Expected indentation of 6 spaces but found 8. Open
onBlur();
- Read upRead up
- Exclude checks
enforce consistent indentation (indent)
There are several common guidelines which require specific indentation of nested blocks and statements, like:
function hello(indentSize, type) {
if (indentSize === 4 && type !== 'tab') {
console.log('Each next indentation will increase on 4 spaces');
}
}
These are the most common scenarios recommended in different style guides:
- Two spaces, not longer and no tabs: Google, npm, Node.js, Idiomatic, Felix
- Tabs: jQuery
- Four spaces: Crockford
Rule Details
This rule enforces a consistent indentation style. The default style is 4 spaces
.
Options
This rule has a mixed option:
For example, for 2-space indentation:
{
"indent": ["error", 2]
}
Or for tabbed indentation:
{
"indent": ["error", "tab"]
}
Examples of incorrect code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
This rule has an object option:
-
"SwitchCase"
(default: 0) enforces indentation level forcase
clauses inswitch
statements -
"VariableDeclarator"
(default: 1) enforces indentation level forvar
declarators; can also take an object to define separate rules forvar
,let
andconst
declarations. -
"outerIIFEBody"
(default: 1) enforces indentation level for file-level IIFEs. -
"MemberExpression"
(off by default) enforces indentation level for multi-line property chains (except in variable declarations and assignments) -
"FunctionDeclaration"
takes an object to define rules for function declarations.-
parameters
(off by default) enforces indentation level for parameters in a function declaration. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the declaration must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function declaration.
-
-
"FunctionExpression"
takes an object to define rules for function expressions.-
parameters
(off by default) enforces indentation level for parameters in a function expression. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the expression must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function expression.
-
-
"CallExpression"
takes an object to define rules for function call expressions.-
arguments
(off by default) enforces indentation level for arguments in a call expression. This can either be a number indicating indentation level, or the string"first"
indicating that all arguments of the expression must be aligned with the first argument.
-
-
"ArrayExpression"
(default: 1) enforces indentation level for elements in arrays. It can also be set to the string"first"
, indicating that all the elements in the array should be aligned with the first element. -
"ObjectExpression"
(default: 1) enforces indentation level for properties in objects. It can be set to the string"first"
, indicating that all properties in the object should be aligned with the first property.
Level of indentation denotes the multiple of the indent specified. Example:
- Indent of 4 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 8 spaces. - Indent of 2 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 4 spaces. - Indent of 2 spaces with
VariableDeclarator
set to{"var": 2, "let": 2, "const": 3}
will indent the multi-line variable declarations with 4 spaces forvar
andlet
, 6 spaces forconst
statements. - Indent of tab with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 2 tabs. - Indent of 2 spaces with
SwitchCase
set to0
will not indentcase
clauses with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to1
will indentcase
clauses with 2 spaces with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to2
will indentcase
clauses with 4 spaces with respect toswitch
statements. - Indent of tab with
SwitchCase
set to2
will indentcase
clauses with 2 tabs with respect toswitch
statements. - Indent of 2 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 2 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 2 spaces. - Indent of 2 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 4 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 8 spaces.
tab
Examples of incorrect code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
/*tab*/b=c;
/*tab*/function foo(d) {
/*tab*//*tab*/e=f;
/*tab*/}
}
SwitchCase
Examples of incorrect code for this rule with the 2, { "SwitchCase": 1 }
options:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
Examples of correct code for this rule with the 2, { "SwitchCase": 1 }
option:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
VariableDeclarator
Examples of incorrect code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 2 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 2 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
outerIIFEBody
Examples of incorrect code for this rule with the options 2, { "outerIIFEBody": 0 }
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
Examples of correct code for this rule with the options 2, {"outerIIFEBody": 0}
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
MemberExpression
Examples of incorrect code for this rule with the 2, { "MemberExpression": 1 }
options:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz()
Examples of correct code for this rule with the 2, { "MemberExpression": 1 }
option:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz();
// Any indentation is permitted in variable declarations and assignments.
var bip = aardvark.badger
.coyote;
FunctionDeclaration
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
FunctionExpression
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
CallExpression
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
ArrayExpression
Examples of incorrect code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of incorrect code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
ObjectExpression
Examples of incorrect code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of correct code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of incorrect code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Examples of correct code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Compatibility
-
JSHint:
indent
- JSCS: validateIndentation Source: http://eslint.org/docs/rules/
Expected indentation of 6 spaces but found 8. Open
this.el = tinymce.DOM.add( contentAreaContainer, editor.settings.placeholder_tag || "label", placeholder_attrs, placeholder_text );
- Read upRead up
- Exclude checks
enforce consistent indentation (indent)
There are several common guidelines which require specific indentation of nested blocks and statements, like:
function hello(indentSize, type) {
if (indentSize === 4 && type !== 'tab') {
console.log('Each next indentation will increase on 4 spaces');
}
}
These are the most common scenarios recommended in different style guides:
- Two spaces, not longer and no tabs: Google, npm, Node.js, Idiomatic, Felix
- Tabs: jQuery
- Four spaces: Crockford
Rule Details
This rule enforces a consistent indentation style. The default style is 4 spaces
.
Options
This rule has a mixed option:
For example, for 2-space indentation:
{
"indent": ["error", 2]
}
Or for tabbed indentation:
{
"indent": ["error", "tab"]
}
Examples of incorrect code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
This rule has an object option:
-
"SwitchCase"
(default: 0) enforces indentation level forcase
clauses inswitch
statements -
"VariableDeclarator"
(default: 1) enforces indentation level forvar
declarators; can also take an object to define separate rules forvar
,let
andconst
declarations. -
"outerIIFEBody"
(default: 1) enforces indentation level for file-level IIFEs. -
"MemberExpression"
(off by default) enforces indentation level for multi-line property chains (except in variable declarations and assignments) -
"FunctionDeclaration"
takes an object to define rules for function declarations.-
parameters
(off by default) enforces indentation level for parameters in a function declaration. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the declaration must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function declaration.
-
-
"FunctionExpression"
takes an object to define rules for function expressions.-
parameters
(off by default) enforces indentation level for parameters in a function expression. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the expression must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function expression.
-
-
"CallExpression"
takes an object to define rules for function call expressions.-
arguments
(off by default) enforces indentation level for arguments in a call expression. This can either be a number indicating indentation level, or the string"first"
indicating that all arguments of the expression must be aligned with the first argument.
-
-
"ArrayExpression"
(default: 1) enforces indentation level for elements in arrays. It can also be set to the string"first"
, indicating that all the elements in the array should be aligned with the first element. -
"ObjectExpression"
(default: 1) enforces indentation level for properties in objects. It can be set to the string"first"
, indicating that all properties in the object should be aligned with the first property.
Level of indentation denotes the multiple of the indent specified. Example:
- Indent of 4 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 8 spaces. - Indent of 2 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 4 spaces. - Indent of 2 spaces with
VariableDeclarator
set to{"var": 2, "let": 2, "const": 3}
will indent the multi-line variable declarations with 4 spaces forvar
andlet
, 6 spaces forconst
statements. - Indent of tab with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 2 tabs. - Indent of 2 spaces with
SwitchCase
set to0
will not indentcase
clauses with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to1
will indentcase
clauses with 2 spaces with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to2
will indentcase
clauses with 4 spaces with respect toswitch
statements. - Indent of tab with
SwitchCase
set to2
will indentcase
clauses with 2 tabs with respect toswitch
statements. - Indent of 2 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 2 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 2 spaces. - Indent of 2 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 4 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 8 spaces.
tab
Examples of incorrect code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
/*tab*/b=c;
/*tab*/function foo(d) {
/*tab*//*tab*/e=f;
/*tab*/}
}
SwitchCase
Examples of incorrect code for this rule with the 2, { "SwitchCase": 1 }
options:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
Examples of correct code for this rule with the 2, { "SwitchCase": 1 }
option:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
VariableDeclarator
Examples of incorrect code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 2 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 2 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
outerIIFEBody
Examples of incorrect code for this rule with the options 2, { "outerIIFEBody": 0 }
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
Examples of correct code for this rule with the options 2, {"outerIIFEBody": 0}
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
MemberExpression
Examples of incorrect code for this rule with the 2, { "MemberExpression": 1 }
options:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz()
Examples of correct code for this rule with the 2, { "MemberExpression": 1 }
option:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz();
// Any indentation is permitted in variable declarations and assignments.
var bip = aardvark.badger
.coyote;
FunctionDeclaration
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
FunctionExpression
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
CallExpression
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
ArrayExpression
Examples of incorrect code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of incorrect code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
ObjectExpression
Examples of incorrect code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of correct code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of incorrect code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Examples of correct code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Compatibility
-
JSHint:
indent
- JSCS: validateIndentation Source: http://eslint.org/docs/rules/
Missing semicolon. Open
}
- Read upRead up
- Exclude checks
require or disallow semicolons instead of ASI (semi)
JavaScript is unique amongst the C-like languages in that it doesn't require semicolons at the end of each statement. In many cases, the JavaScript engine can determine that a semicolon should be in a certain spot and will automatically add it. This feature is known as automatic semicolon insertion (ASI) and is considered one of the more controversial features of JavaScript. For example, the following lines are both valid:
var name = "ESLint"
var website = "eslint.org";
On the first line, the JavaScript engine will automatically insert a semicolon, so this is not considered a syntax error. The JavaScript engine still knows how to interpret the line and knows that the line end indicates the end of the statement.
In the debate over ASI, there are generally two schools of thought. The first is that we should treat ASI as if it didn't exist and always include semicolons manually. The rationale is that it's easier to always include semicolons than to try to remember when they are or are not required, and thus decreases the possibility of introducing an error.
However, the ASI mechanism can sometimes be tricky to people who are using semicolons. For example, consider this code:
return
{
name: "ESLint"
};
This may look like a return
statement that returns an object literal, however, the JavaScript engine will interpret this code as:
return;
{
name: "ESLint";
}
Effectively, a semicolon is inserted after the return
statement, causing the code below it (a labeled literal inside a block) to be unreachable. This rule and the [no-unreachable](no-unreachable.md) rule will protect your code from such cases.
On the other side of the argument are those who says that since semicolons are inserted automatically, they are optional and do not need to be inserted manually. However, the ASI mechanism can also be tricky to people who don't use semicolons. For example, consider this code:
var globalCounter = { }
(function () {
var n = 0
globalCounter.increment = function () {
return ++n
}
})()
In this example, a semicolon will not be inserted after the first line, causing a run-time error (because an empty object is called as if it's a function). The [no-unexpected-multiline](no-unexpected-multiline.md) rule can protect your code from such cases.
Although ASI allows for more freedom over your coding style, it can also make your code behave in an unexpected way, whether you use semicolons or not. Therefore, it is best to know when ASI takes place and when it does not, and have ESLint protect your code from these potentially unexpected cases. In short, as once described by Isaac Schlueter, a \n
character always ends a statement (just like a semicolon) unless one of the following is true:
- The statement has an unclosed paren, array literal, or object literal or ends in some other way that is not a valid way to end a statement. (For instance, ending with
.
or,
.) - The line is
--
or++
(in which case it will decrement/increment the next token.) - It is a
for()
,while()
,do
,if()
, orelse
, and there is no{
- The next line starts with
[
,(
,+
,*
,/
,-
,,
,.
, or some other binary operator that can only be found between two tokens in a single expression.
Rule Details
This rule enforces consistent use of semicolons.
Options
This rule has two options, a string option and an object option.
String option:
-
"always"
(default) requires semicolons at the end of statements -
"never"
disallows semicolons as the end of statements (except to disambiguate statements beginning with[
,(
,/
,+
, or-
)
Object option:
-
"omitLastInOneLineBlock": true
ignores the last semicolon in a block in which its braces (and therefore the content of the block) are in the same line
always
Examples of incorrect code for this rule with the default "always"
option:
/*eslint semi: ["error", "always"]*/
var name = "ESLint"
object.method = function() {
// ...
}
Examples of correct code for this rule with the default "always"
option:
/*eslint semi: "error"*/
var name = "ESLint";
object.method = function() {
// ...
};
never
Examples of incorrect code for this rule with the "never"
option:
/*eslint semi: ["error", "never"]*/
var name = "ESLint";
object.method = function() {
// ...
};
Examples of correct code for this rule with the "never"
option:
/*eslint semi: ["error", "never"]*/
var name = "ESLint"
object.method = function() {
// ...
}
var name = "ESLint"
;(function() {
// ...
})()
omitLastInOneLineBlock
Examples of additional correct code for this rule with the "always", { "omitLastInOneLineBlock": true }
options:
/*eslint semi: ["error", "always", { "omitLastInOneLineBlock": true}] */
if (foo) { bar() }
if (foo) { bar(); baz() }
When Not To Use It
If you do not want to enforce semicolon usage (or omission) in any particular way, then you can turn this rule off.
Further Reading
Related Rules
- [no-extra-semi](no-extra-semi.md)
- [no-unexpected-multiline](no-unexpected-multiline.md)
- [semi-spacing](semi-spacing.md) Source: http://eslint.org/docs/rules/
Expected indentation of 2 spaces but found 4. Open
Label.prototype.hide = function(){
- Read upRead up
- Exclude checks
enforce consistent indentation (indent)
There are several common guidelines which require specific indentation of nested blocks and statements, like:
function hello(indentSize, type) {
if (indentSize === 4 && type !== 'tab') {
console.log('Each next indentation will increase on 4 spaces');
}
}
These are the most common scenarios recommended in different style guides:
- Two spaces, not longer and no tabs: Google, npm, Node.js, Idiomatic, Felix
- Tabs: jQuery
- Four spaces: Crockford
Rule Details
This rule enforces a consistent indentation style. The default style is 4 spaces
.
Options
This rule has a mixed option:
For example, for 2-space indentation:
{
"indent": ["error", 2]
}
Or for tabbed indentation:
{
"indent": ["error", "tab"]
}
Examples of incorrect code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
This rule has an object option:
-
"SwitchCase"
(default: 0) enforces indentation level forcase
clauses inswitch
statements -
"VariableDeclarator"
(default: 1) enforces indentation level forvar
declarators; can also take an object to define separate rules forvar
,let
andconst
declarations. -
"outerIIFEBody"
(default: 1) enforces indentation level for file-level IIFEs. -
"MemberExpression"
(off by default) enforces indentation level for multi-line property chains (except in variable declarations and assignments) -
"FunctionDeclaration"
takes an object to define rules for function declarations.-
parameters
(off by default) enforces indentation level for parameters in a function declaration. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the declaration must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function declaration.
-
-
"FunctionExpression"
takes an object to define rules for function expressions.-
parameters
(off by default) enforces indentation level for parameters in a function expression. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the expression must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function expression.
-
-
"CallExpression"
takes an object to define rules for function call expressions.-
arguments
(off by default) enforces indentation level for arguments in a call expression. This can either be a number indicating indentation level, or the string"first"
indicating that all arguments of the expression must be aligned with the first argument.
-
-
"ArrayExpression"
(default: 1) enforces indentation level for elements in arrays. It can also be set to the string"first"
, indicating that all the elements in the array should be aligned with the first element. -
"ObjectExpression"
(default: 1) enforces indentation level for properties in objects. It can be set to the string"first"
, indicating that all properties in the object should be aligned with the first property.
Level of indentation denotes the multiple of the indent specified. Example:
- Indent of 4 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 8 spaces. - Indent of 2 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 4 spaces. - Indent of 2 spaces with
VariableDeclarator
set to{"var": 2, "let": 2, "const": 3}
will indent the multi-line variable declarations with 4 spaces forvar
andlet
, 6 spaces forconst
statements. - Indent of tab with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 2 tabs. - Indent of 2 spaces with
SwitchCase
set to0
will not indentcase
clauses with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to1
will indentcase
clauses with 2 spaces with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to2
will indentcase
clauses with 4 spaces with respect toswitch
statements. - Indent of tab with
SwitchCase
set to2
will indentcase
clauses with 2 tabs with respect toswitch
statements. - Indent of 2 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 2 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 2 spaces. - Indent of 2 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 4 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 8 spaces.
tab
Examples of incorrect code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
/*tab*/b=c;
/*tab*/function foo(d) {
/*tab*//*tab*/e=f;
/*tab*/}
}
SwitchCase
Examples of incorrect code for this rule with the 2, { "SwitchCase": 1 }
options:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
Examples of correct code for this rule with the 2, { "SwitchCase": 1 }
option:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
VariableDeclarator
Examples of incorrect code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 2 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 2 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
outerIIFEBody
Examples of incorrect code for this rule with the options 2, { "outerIIFEBody": 0 }
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
Examples of correct code for this rule with the options 2, {"outerIIFEBody": 0}
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
MemberExpression
Examples of incorrect code for this rule with the 2, { "MemberExpression": 1 }
options:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz()
Examples of correct code for this rule with the 2, { "MemberExpression": 1 }
option:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz();
// Any indentation is permitted in variable declarations and assignments.
var bip = aardvark.badger
.coyote;
FunctionDeclaration
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
FunctionExpression
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
CallExpression
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
ArrayExpression
Examples of incorrect code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of incorrect code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
ObjectExpression
Examples of incorrect code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of correct code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of incorrect code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Examples of correct code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Compatibility
-
JSHint:
indent
- JSCS: validateIndentation Source: http://eslint.org/docs/rules/
Expected indentation of 6 spaces but found 8. Open
tinymce.DOM.setStyle( this.el, 'display', '' );
- Read upRead up
- Exclude checks
enforce consistent indentation (indent)
There are several common guidelines which require specific indentation of nested blocks and statements, like:
function hello(indentSize, type) {
if (indentSize === 4 && type !== 'tab') {
console.log('Each next indentation will increase on 4 spaces');
}
}
These are the most common scenarios recommended in different style guides:
- Two spaces, not longer and no tabs: Google, npm, Node.js, Idiomatic, Felix
- Tabs: jQuery
- Four spaces: Crockford
Rule Details
This rule enforces a consistent indentation style. The default style is 4 spaces
.
Options
This rule has a mixed option:
For example, for 2-space indentation:
{
"indent": ["error", 2]
}
Or for tabbed indentation:
{
"indent": ["error", "tab"]
}
Examples of incorrect code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
This rule has an object option:
-
"SwitchCase"
(default: 0) enforces indentation level forcase
clauses inswitch
statements -
"VariableDeclarator"
(default: 1) enforces indentation level forvar
declarators; can also take an object to define separate rules forvar
,let
andconst
declarations. -
"outerIIFEBody"
(default: 1) enforces indentation level for file-level IIFEs. -
"MemberExpression"
(off by default) enforces indentation level for multi-line property chains (except in variable declarations and assignments) -
"FunctionDeclaration"
takes an object to define rules for function declarations.-
parameters
(off by default) enforces indentation level for parameters in a function declaration. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the declaration must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function declaration.
-
-
"FunctionExpression"
takes an object to define rules for function expressions.-
parameters
(off by default) enforces indentation level for parameters in a function expression. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the expression must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function expression.
-
-
"CallExpression"
takes an object to define rules for function call expressions.-
arguments
(off by default) enforces indentation level for arguments in a call expression. This can either be a number indicating indentation level, or the string"first"
indicating that all arguments of the expression must be aligned with the first argument.
-
-
"ArrayExpression"
(default: 1) enforces indentation level for elements in arrays. It can also be set to the string"first"
, indicating that all the elements in the array should be aligned with the first element. -
"ObjectExpression"
(default: 1) enforces indentation level for properties in objects. It can be set to the string"first"
, indicating that all properties in the object should be aligned with the first property.
Level of indentation denotes the multiple of the indent specified. Example:
- Indent of 4 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 8 spaces. - Indent of 2 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 4 spaces. - Indent of 2 spaces with
VariableDeclarator
set to{"var": 2, "let": 2, "const": 3}
will indent the multi-line variable declarations with 4 spaces forvar
andlet
, 6 spaces forconst
statements. - Indent of tab with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 2 tabs. - Indent of 2 spaces with
SwitchCase
set to0
will not indentcase
clauses with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to1
will indentcase
clauses with 2 spaces with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to2
will indentcase
clauses with 4 spaces with respect toswitch
statements. - Indent of tab with
SwitchCase
set to2
will indentcase
clauses with 2 tabs with respect toswitch
statements. - Indent of 2 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 2 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 2 spaces. - Indent of 2 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 4 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 8 spaces.
tab
Examples of incorrect code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
/*tab*/b=c;
/*tab*/function foo(d) {
/*tab*//*tab*/e=f;
/*tab*/}
}
SwitchCase
Examples of incorrect code for this rule with the 2, { "SwitchCase": 1 }
options:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
Examples of correct code for this rule with the 2, { "SwitchCase": 1 }
option:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
VariableDeclarator
Examples of incorrect code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 2 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 2 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
outerIIFEBody
Examples of incorrect code for this rule with the options 2, { "outerIIFEBody": 0 }
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
Examples of correct code for this rule with the options 2, {"outerIIFEBody": 0}
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
MemberExpression
Examples of incorrect code for this rule with the 2, { "MemberExpression": 1 }
options:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz()
Examples of correct code for this rule with the 2, { "MemberExpression": 1 }
option:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz();
// Any indentation is permitted in variable declarations and assignments.
var bip = aardvark.badger
.coyote;
FunctionDeclaration
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
FunctionExpression
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
CallExpression
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
ArrayExpression
Examples of incorrect code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of incorrect code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
ObjectExpression
Examples of incorrect code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of correct code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of incorrect code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Examples of correct code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Compatibility
-
JSHint:
indent
- JSCS: validateIndentation Source: http://eslint.org/docs/rules/
Missing space before function parentheses. Open
editor.on('init', function() {
- Read upRead up
- Exclude checks
Require or disallow a space before function parenthesis (space-before-function-paren)
When formatting a function, whitespace is allowed between the function name or function
keyword and the opening paren. Named functions also require a space between the function
keyword and the function name, but anonymous functions require no whitespace. For example:
function withoutSpace(x) {
// ...
}
function withSpace (x) {
// ...
}
var anonymousWithoutSpace = function() {};
var anonymousWithSpace = function () {};
Style guides may require a space after the function
keyword for anonymous functions, while others specify no whitespace. Similarly, the space after a function name may or may not be required.
Rule Details
This rule aims to enforce consistent spacing before function parentheses and as such, will warn whenever whitespace doesn't match the preferences specified.
Options
This rule has a string option or an object option:
{
"space-before-function-paren": ["error", "always"],
// or
"space-before-function-paren": ["error", {
"anonymous": "always",
"named": "always",
"asyncArrow": "ignore"
}],
}
-
always
(default) requires a space followed by the(
of arguments. -
never
disallows any space followed by the(
of arguments.
The string option does not check async arrow function expressions for backward compatibility.
You can also use a separate option for each type of function.
Each of the following options can be set to "always"
, "never"
, or "ignore"
.
Default is "always"
basically.
-
anonymous
is for anonymous function expressions (e.g.function () {}
). -
named
is for named function expressions (e.g.function foo () {}
). -
asyncArrow
is for async arrow function expressions (e.g.async () => {}
).asyncArrow
is set to"ignore"
by default for backwards compatibility.
"always"
Examples of incorrect code for this rule with the default "always"
option:
/*eslint space-before-function-paren: "error"*/
/*eslint-env es6*/
function foo() {
// ...
}
var bar = function() {
// ...
};
var bar = function foo() {
// ...
};
class Foo {
constructor() {
// ...
}
}
var foo = {
bar() {
// ...
}
};
Examples of correct code for this rule with the default "always"
option:
/*eslint space-before-function-paren: "error"*/
/*eslint-env es6*/
function foo () {
// ...
}
var bar = function () {
// ...
};
var bar = function foo () {
// ...
};
class Foo {
constructor () {
// ...
}
}
var foo = {
bar () {
// ...
}
};
// async arrow function expressions are ignored by default.
var foo = async () => 1
var foo = async() => 1
"never"
Examples of incorrect code for this rule with the "never"
option:
/*eslint space-before-function-paren: ["error", "never"]*/
/*eslint-env es6*/
function foo () {
// ...
}
var bar = function () {
// ...
};
var bar = function foo () {
// ...
};
class Foo {
constructor () {
// ...
}
}
var foo = {
bar () {
// ...
}
};
Examples of correct code for this rule with the "never"
option:
/*eslint space-before-function-paren: ["error", "never"]*/
/*eslint-env es6*/
function foo() {
// ...
}
var bar = function() {
// ...
};
var bar = function foo() {
// ...
};
class Foo {
constructor() {
// ...
}
}
var foo = {
bar() {
// ...
}
};
// async arrow function expressions are ignored by default.
var foo = async () => 1
var foo = async() => 1
{"anonymous": "always", "named": "never", "asyncArrow": "always"}
Examples of incorrect code for this rule with the {"anonymous": "always", "named": "never", "asyncArrow": "always"}
option:
/*eslint space-before-function-paren: ["error", {"anonymous": "always", "named": "never", "asyncArrow": "always"}]*/
/*eslint-env es6*/
function foo () {
// ...
}
var bar = function() {
// ...
};
class Foo {
constructor () {
// ...
}
}
var foo = {
bar () {
// ...
}
};
var foo = async(a) => await a
Examples of correct code for this rule with the {"anonymous": "always", "named": "never", "asyncArrow": "always"}
option:
/*eslint space-before-function-paren: ["error", {"anonymous": "always", "named": "never", "asyncArrow": "always"}]*/
/*eslint-env es6*/
function foo() {
// ...
}
var bar = function () {
// ...
};
class Foo {
constructor() {
// ...
}
}
var foo = {
bar() {
// ...
}
};
var foo = async (a) => await a
{"anonymous": "never", "named": "always"}
Examples of incorrect code for this rule with the {"anonymous": "never", "named": "always"}
option:
/*eslint space-before-function-paren: ["error", { "anonymous": "never", "named": "always" }]*/
/*eslint-env es6*/
function foo() {
// ...
}
var bar = function () {
// ...
};
class Foo {
constructor() {
// ...
}
}
var foo = {
bar() {
// ...
}
};
Examples of correct code for this rule with the {"anonymous": "never", "named": "always"}
option:
/*eslint space-before-function-paren: ["error", { "anonymous": "never", "named": "always" }]*/
/*eslint-env es6*/
function foo () {
// ...
}
var bar = function() {
// ...
};
class Foo {
constructor () {
// ...
}
}
var foo = {
bar () {
// ...
}
};
{"anonymous": "ignore", "named": "always"}
Examples of incorrect code for this rule with the {"anonymous": "ignore", "named": "always"}
option:
/*eslint space-before-function-paren: ["error", { "anonymous": "ignore", "named": "always" }]*/
/*eslint-env es6*/
function foo() {
// ...
}
class Foo {
constructor() {
// ...
}
}
var foo = {
bar() {
// ...
}
};
Examples of correct code for this rule with the {"anonymous": "ignore", "named": "always"}
option:
/*eslint space-before-function-paren: ["error", { "anonymous": "ignore", "named": "always" }]*/
/*eslint-env es6*/
var bar = function() {
// ...
};
var bar = function () {
// ...
};
function foo () {
// ...
}
class Foo {
constructor () {
// ...
}
}
var foo = {
bar () {
// ...
}
};
When Not To Use It
You can turn this rule off if you are not concerned with the consistency of spacing before function parenthesis.
Related Rules
- [space-after-keywords](space-after-keywords.md)
- [space-return-throw-case](space-return-throw-case.md) Source: http://eslint.org/docs/rules/
Expected indentation of 6 spaces but found 8. Open
editor.on('setContent', onBlur);
- Read upRead up
- Exclude checks
enforce consistent indentation (indent)
There are several common guidelines which require specific indentation of nested blocks and statements, like:
function hello(indentSize, type) {
if (indentSize === 4 && type !== 'tab') {
console.log('Each next indentation will increase on 4 spaces');
}
}
These are the most common scenarios recommended in different style guides:
- Two spaces, not longer and no tabs: Google, npm, Node.js, Idiomatic, Felix
- Tabs: jQuery
- Four spaces: Crockford
Rule Details
This rule enforces a consistent indentation style. The default style is 4 spaces
.
Options
This rule has a mixed option:
For example, for 2-space indentation:
{
"indent": ["error", 2]
}
Or for tabbed indentation:
{
"indent": ["error", "tab"]
}
Examples of incorrect code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
This rule has an object option:
-
"SwitchCase"
(default: 0) enforces indentation level forcase
clauses inswitch
statements -
"VariableDeclarator"
(default: 1) enforces indentation level forvar
declarators; can also take an object to define separate rules forvar
,let
andconst
declarations. -
"outerIIFEBody"
(default: 1) enforces indentation level for file-level IIFEs. -
"MemberExpression"
(off by default) enforces indentation level for multi-line property chains (except in variable declarations and assignments) -
"FunctionDeclaration"
takes an object to define rules for function declarations.-
parameters
(off by default) enforces indentation level for parameters in a function declaration. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the declaration must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function declaration.
-
-
"FunctionExpression"
takes an object to define rules for function expressions.-
parameters
(off by default) enforces indentation level for parameters in a function expression. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the expression must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function expression.
-
-
"CallExpression"
takes an object to define rules for function call expressions.-
arguments
(off by default) enforces indentation level for arguments in a call expression. This can either be a number indicating indentation level, or the string"first"
indicating that all arguments of the expression must be aligned with the first argument.
-
-
"ArrayExpression"
(default: 1) enforces indentation level for elements in arrays. It can also be set to the string"first"
, indicating that all the elements in the array should be aligned with the first element. -
"ObjectExpression"
(default: 1) enforces indentation level for properties in objects. It can be set to the string"first"
, indicating that all properties in the object should be aligned with the first property.
Level of indentation denotes the multiple of the indent specified. Example:
- Indent of 4 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 8 spaces. - Indent of 2 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 4 spaces. - Indent of 2 spaces with
VariableDeclarator
set to{"var": 2, "let": 2, "const": 3}
will indent the multi-line variable declarations with 4 spaces forvar
andlet
, 6 spaces forconst
statements. - Indent of tab with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 2 tabs. - Indent of 2 spaces with
SwitchCase
set to0
will not indentcase
clauses with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to1
will indentcase
clauses with 2 spaces with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to2
will indentcase
clauses with 4 spaces with respect toswitch
statements. - Indent of tab with
SwitchCase
set to2
will indentcase
clauses with 2 tabs with respect toswitch
statements. - Indent of 2 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 2 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 2 spaces. - Indent of 2 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 4 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 8 spaces.
tab
Examples of incorrect code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
/*tab*/b=c;
/*tab*/function foo(d) {
/*tab*//*tab*/e=f;
/*tab*/}
}
SwitchCase
Examples of incorrect code for this rule with the 2, { "SwitchCase": 1 }
options:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
Examples of correct code for this rule with the 2, { "SwitchCase": 1 }
option:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
VariableDeclarator
Examples of incorrect code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 2 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 2 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
outerIIFEBody
Examples of incorrect code for this rule with the options 2, { "outerIIFEBody": 0 }
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
Examples of correct code for this rule with the options 2, {"outerIIFEBody": 0}
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
MemberExpression
Examples of incorrect code for this rule with the 2, { "MemberExpression": 1 }
options:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz()
Examples of correct code for this rule with the 2, { "MemberExpression": 1 }
option:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz();
// Any indentation is permitted in variable declarations and assignments.
var bip = aardvark.badger
.coyote;
FunctionDeclaration
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
FunctionExpression
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
CallExpression
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
ArrayExpression
Examples of incorrect code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of incorrect code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
ObjectExpression
Examples of incorrect code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of correct code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of incorrect code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Examples of correct code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Compatibility
-
JSHint:
indent
- JSCS: validateIndentation Source: http://eslint.org/docs/rules/
Expected indentation of 10 spaces but found 12. Open
label.hide();
- Read upRead up
- Exclude checks
enforce consistent indentation (indent)
There are several common guidelines which require specific indentation of nested blocks and statements, like:
function hello(indentSize, type) {
if (indentSize === 4 && type !== 'tab') {
console.log('Each next indentation will increase on 4 spaces');
}
}
These are the most common scenarios recommended in different style guides:
- Two spaces, not longer and no tabs: Google, npm, Node.js, Idiomatic, Felix
- Tabs: jQuery
- Four spaces: Crockford
Rule Details
This rule enforces a consistent indentation style. The default style is 4 spaces
.
Options
This rule has a mixed option:
For example, for 2-space indentation:
{
"indent": ["error", 2]
}
Or for tabbed indentation:
{
"indent": ["error", "tab"]
}
Examples of incorrect code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
This rule has an object option:
-
"SwitchCase"
(default: 0) enforces indentation level forcase
clauses inswitch
statements -
"VariableDeclarator"
(default: 1) enforces indentation level forvar
declarators; can also take an object to define separate rules forvar
,let
andconst
declarations. -
"outerIIFEBody"
(default: 1) enforces indentation level for file-level IIFEs. -
"MemberExpression"
(off by default) enforces indentation level for multi-line property chains (except in variable declarations and assignments) -
"FunctionDeclaration"
takes an object to define rules for function declarations.-
parameters
(off by default) enforces indentation level for parameters in a function declaration. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the declaration must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function declaration.
-
-
"FunctionExpression"
takes an object to define rules for function expressions.-
parameters
(off by default) enforces indentation level for parameters in a function expression. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the expression must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function expression.
-
-
"CallExpression"
takes an object to define rules for function call expressions.-
arguments
(off by default) enforces indentation level for arguments in a call expression. This can either be a number indicating indentation level, or the string"first"
indicating that all arguments of the expression must be aligned with the first argument.
-
-
"ArrayExpression"
(default: 1) enforces indentation level for elements in arrays. It can also be set to the string"first"
, indicating that all the elements in the array should be aligned with the first element. -
"ObjectExpression"
(default: 1) enforces indentation level for properties in objects. It can be set to the string"first"
, indicating that all properties in the object should be aligned with the first property.
Level of indentation denotes the multiple of the indent specified. Example:
- Indent of 4 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 8 spaces. - Indent of 2 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 4 spaces. - Indent of 2 spaces with
VariableDeclarator
set to{"var": 2, "let": 2, "const": 3}
will indent the multi-line variable declarations with 4 spaces forvar
andlet
, 6 spaces forconst
statements. - Indent of tab with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 2 tabs. - Indent of 2 spaces with
SwitchCase
set to0
will not indentcase
clauses with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to1
will indentcase
clauses with 2 spaces with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to2
will indentcase
clauses with 4 spaces with respect toswitch
statements. - Indent of tab with
SwitchCase
set to2
will indentcase
clauses with 2 tabs with respect toswitch
statements. - Indent of 2 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 2 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 2 spaces. - Indent of 2 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 4 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 8 spaces.
tab
Examples of incorrect code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
/*tab*/b=c;
/*tab*/function foo(d) {
/*tab*//*tab*/e=f;
/*tab*/}
}
SwitchCase
Examples of incorrect code for this rule with the 2, { "SwitchCase": 1 }
options:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
Examples of correct code for this rule with the 2, { "SwitchCase": 1 }
option:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
VariableDeclarator
Examples of incorrect code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 2 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 2 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
outerIIFEBody
Examples of incorrect code for this rule with the options 2, { "outerIIFEBody": 0 }
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
Examples of correct code for this rule with the options 2, {"outerIIFEBody": 0}
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
MemberExpression
Examples of incorrect code for this rule with the 2, { "MemberExpression": 1 }
options:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz()
Examples of correct code for this rule with the 2, { "MemberExpression": 1 }
option:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz();
// Any indentation is permitted in variable declarations and assignments.
var bip = aardvark.badger
.coyote;
FunctionDeclaration
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
FunctionExpression
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
CallExpression
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
ArrayExpression
Examples of incorrect code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of incorrect code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
ObjectExpression
Examples of incorrect code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of correct code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of incorrect code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Examples of correct code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Compatibility
-
JSHint:
indent
- JSCS: validateIndentation Source: http://eslint.org/docs/rules/
A space is required after '{'. Open
var placeholder_attrs = editor.settings.placeholder_attrs || {style: {position: 'absolute', top:'5px', left:0, color: '#888', padding: '1%', width:'98%', overflow: 'hidden', 'white-space': 'pre-wrap'} };
- Read upRead up
- Exclude checks
enforce consistent spacing inside braces (object-curly-spacing)
While formatting preferences are very personal, a number of style guides require or disallow spaces between curly braces in the following situations:
// simple object literals
var obj = { foo: "bar" };
// nested object literals
var obj = { foo: { zoo: "bar" } };
// destructuring assignment (EcmaScript 6)
var { x, y } = y;
// import/export declarations (EcmaScript 6)
import { foo } from "bar";
export { foo };
Rule Details
This rule enforce consistent spacing inside braces of object literals, destructuring assignments, and import/export specifiers.
Options
This rule has two options, a string option and an object option.
String option:
-
"never"
(default) disallows spacing inside of braces -
"always"
requires spacing inside of braces (except{}
)
Object option:
-
"arraysInObjects": true
requires spacing inside of braces of objects beginning and/or ending with an array element (applies when the first option is set tonever
) -
"arraysInObjects": false
disallows spacing inside of braces of objects beginning and/or ending with an array element (applies when the first option is set toalways
) -
"objectsInObjects": true
requires spacing inside of braces of objects beginning and/or ending with an object element (applies when the first option is set tonever
) -
"objectsInObjects": false
disallows spacing inside of braces of objects beginning and/or ending with an object element (applies when the first option is set toalways
)
never
Examples of incorrect code for this rule with the default "never"
option:
/*eslint object-curly-spacing: ["error", "never"]*/
var obj = { 'foo': 'bar' };
var obj = {'foo': 'bar' };
var obj = { baz: {'foo': 'qux'}, bar};
var obj = {baz: { 'foo': 'qux'}, bar};
var {x } = y;
import { foo } from 'bar';
Examples of correct code for this rule with the default "never"
option:
/*eslint object-curly-spacing: ["error", "never"]*/
var obj = {'foo': 'bar'};
var obj = {'foo': {'bar': 'baz'}, 'qux': 'quxx'};
var obj = {
'foo': 'bar'
};
var obj = {'foo': 'bar'
};
var obj = {
'foo':'bar'};
var obj = {};
var {x} = y;
import {foo} from 'bar';
always
Examples of incorrect code for this rule with the "always"
option:
/*eslint object-curly-spacing: ["error", "always"]*/
var obj = {'foo': 'bar'};
var obj = {'foo': 'bar' };
var obj = { baz: {'foo': 'qux'}, bar};
var obj = {baz: { 'foo': 'qux' }, bar};
var obj = {'foo': 'bar'
};
var obj = {
'foo':'bar'};
var {x} = y;
import {foo } from 'bar';
Examples of correct code for this rule with the "always"
option:
/*eslint object-curly-spacing: ["error", "always"]*/
var obj = {};
var obj = { 'foo': 'bar' };
var obj = { 'foo': { 'bar': 'baz' }, 'qux': 'quxx' };
var obj = {
'foo': 'bar'
};
var { x } = y;
import { foo } from 'bar';
arraysInObjects
Examples of additional correct code for this rule with the "never", { "arraysInObjects": true }
options:
/*eslint object-curly-spacing: ["error", "never", { "arraysInObjects": true }]*/
var obj = {"foo": [ 1, 2 ] };
var obj = {"foo": [ "baz", "bar" ] };
Examples of additional correct code for this rule with the "always", { "arraysInObjects": false }
options:
/*eslint object-curly-spacing: ["error", "always", { "arraysInObjects": false }]*/
var obj = { "foo": [ 1, 2 ]};
var obj = { "foo": [ "baz", "bar" ]};
objectsInObjects
Examples of additional correct code for this rule with the "never", { "objectsInObjects": true }
options:
/*eslint object-curly-spacing: ["error", "never", { "objectsInObjects": true }]*/
var obj = {"foo": {"baz": 1, "bar": 2} };
Examples of additional correct code for this rule with the "always", { "objectsInObjects": false }
options:
/*eslint object-curly-spacing: ["error", "always", { "objectsInObjects": false }]*/
var obj = { "foo": { "baz": 1, "bar": 2 }};
When Not To Use It
You can turn this rule off if you are not concerned with the consistency of spacing between curly braces.
Related Rules
- [comma-spacing](comma-spacing.md)
- [space-in-parens](space-in-parens.md) Source: http://eslint.org/docs/rules/
Unexpected var, use let or const instead. Open
var label = new Label;
- Read upRead up
- Exclude checks
require let
or const
instead of var
(no-var)
ECMAScript 6 allows programmers to create variables with block scope instead of function scope using the let
and const
keywords. Block scope is common in many other programming languages and helps programmers avoid mistakes
such as:
var count = people.length;
var enoughFood = count > sandwiches.length;
if (enoughFood) {
var count = sandwiches.length; // accidentally overriding the count variable
console.log("We have " + count + " sandwiches for everyone. Plenty for all!");
}
// our count variable is no longer accurate
console.log("We have " + count + " people and " + sandwiches.length + " sandwiches!");
Rule Details
This rule is aimed at discouraging the use of var
and encouraging the use of const
or let
instead.
Examples
Examples of incorrect code for this rule:
/*eslint no-var: "error"*/
var x = "y";
var CONFIG = {};
Examples of correct code for this rule:
/*eslint no-var: "error"*/
/*eslint-env es6*/
let x = "y";
const CONFIG = {};
When Not To Use It
In addition to non-ES6 environments, existing JavaScript projects that are beginning to introduce ES6 into their
codebase may not want to apply this rule if the cost of migrating from var
to let
is too costly.
Source: http://eslint.org/docs/rules/
Missing '()' invoking a constructor. Open
var label = new Label;
- Read upRead up
- Exclude checks
require parentheses when invoking a constructor with no arguments (new-parens)
JavaScript allows the omission of parentheses when invoking a function via the new
keyword and the constructor has no arguments. However, some coders believe that omitting the parentheses is inconsistent with the rest of the language and thus makes code less clear.
var person = new Person;
Rule Details
This rule requires parentheses when invoking a constructor with no arguments using the new
keyword in order to increase code clarity.
Examples of incorrect code for this rule:
/*eslint new-parens: "error"*/
var person = new Person;
var person = new (Person);
Examples of correct code for this rule:
/*eslint new-parens: "error"*/
var person = new Person();
var person = new (Person)();
Source: http://eslint.org/docs/rules/
Expected indentation of 10 spaces but found 12. Open
if (editor.getContent() == '') {
- Read upRead up
- Exclude checks
enforce consistent indentation (indent)
There are several common guidelines which require specific indentation of nested blocks and statements, like:
function hello(indentSize, type) {
if (indentSize === 4 && type !== 'tab') {
console.log('Each next indentation will increase on 4 spaces');
}
}
These are the most common scenarios recommended in different style guides:
- Two spaces, not longer and no tabs: Google, npm, Node.js, Idiomatic, Felix
- Tabs: jQuery
- Four spaces: Crockford
Rule Details
This rule enforces a consistent indentation style. The default style is 4 spaces
.
Options
This rule has a mixed option:
For example, for 2-space indentation:
{
"indent": ["error", 2]
}
Or for tabbed indentation:
{
"indent": ["error", "tab"]
}
Examples of incorrect code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
This rule has an object option:
-
"SwitchCase"
(default: 0) enforces indentation level forcase
clauses inswitch
statements -
"VariableDeclarator"
(default: 1) enforces indentation level forvar
declarators; can also take an object to define separate rules forvar
,let
andconst
declarations. -
"outerIIFEBody"
(default: 1) enforces indentation level for file-level IIFEs. -
"MemberExpression"
(off by default) enforces indentation level for multi-line property chains (except in variable declarations and assignments) -
"FunctionDeclaration"
takes an object to define rules for function declarations.-
parameters
(off by default) enforces indentation level for parameters in a function declaration. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the declaration must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function declaration.
-
-
"FunctionExpression"
takes an object to define rules for function expressions.-
parameters
(off by default) enforces indentation level for parameters in a function expression. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the expression must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function expression.
-
-
"CallExpression"
takes an object to define rules for function call expressions.-
arguments
(off by default) enforces indentation level for arguments in a call expression. This can either be a number indicating indentation level, or the string"first"
indicating that all arguments of the expression must be aligned with the first argument.
-
-
"ArrayExpression"
(default: 1) enforces indentation level for elements in arrays. It can also be set to the string"first"
, indicating that all the elements in the array should be aligned with the first element. -
"ObjectExpression"
(default: 1) enforces indentation level for properties in objects. It can be set to the string"first"
, indicating that all properties in the object should be aligned with the first property.
Level of indentation denotes the multiple of the indent specified. Example:
- Indent of 4 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 8 spaces. - Indent of 2 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 4 spaces. - Indent of 2 spaces with
VariableDeclarator
set to{"var": 2, "let": 2, "const": 3}
will indent the multi-line variable declarations with 4 spaces forvar
andlet
, 6 spaces forconst
statements. - Indent of tab with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 2 tabs. - Indent of 2 spaces with
SwitchCase
set to0
will not indentcase
clauses with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to1
will indentcase
clauses with 2 spaces with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to2
will indentcase
clauses with 4 spaces with respect toswitch
statements. - Indent of tab with
SwitchCase
set to2
will indentcase
clauses with 2 tabs with respect toswitch
statements. - Indent of 2 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 2 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 2 spaces. - Indent of 2 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 4 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 8 spaces.
tab
Examples of incorrect code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
/*tab*/b=c;
/*tab*/function foo(d) {
/*tab*//*tab*/e=f;
/*tab*/}
}
SwitchCase
Examples of incorrect code for this rule with the 2, { "SwitchCase": 1 }
options:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
Examples of correct code for this rule with the 2, { "SwitchCase": 1 }
option:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
VariableDeclarator
Examples of incorrect code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 2 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 2 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
outerIIFEBody
Examples of incorrect code for this rule with the options 2, { "outerIIFEBody": 0 }
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
Examples of correct code for this rule with the options 2, {"outerIIFEBody": 0}
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
MemberExpression
Examples of incorrect code for this rule with the 2, { "MemberExpression": 1 }
options:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz()
Examples of correct code for this rule with the 2, { "MemberExpression": 1 }
option:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz();
// Any indentation is permitted in variable declarations and assignments.
var bip = aardvark.badger
.coyote;
FunctionDeclaration
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
FunctionExpression
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
CallExpression
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
ArrayExpression
Examples of incorrect code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of incorrect code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
ObjectExpression
Examples of incorrect code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of correct code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of incorrect code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Examples of correct code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Compatibility
-
JSHint:
indent
- JSCS: validateIndentation Source: http://eslint.org/docs/rules/
Unexpected var, use let or const instead. Open
var contentAreaContainer = editor.getContentAreaContainer();
- Read upRead up
- Exclude checks
require let
or const
instead of var
(no-var)
ECMAScript 6 allows programmers to create variables with block scope instead of function scope using the let
and const
keywords. Block scope is common in many other programming languages and helps programmers avoid mistakes
such as:
var count = people.length;
var enoughFood = count > sandwiches.length;
if (enoughFood) {
var count = sandwiches.length; // accidentally overriding the count variable
console.log("We have " + count + " sandwiches for everyone. Plenty for all!");
}
// our count variable is no longer accurate
console.log("We have " + count + " people and " + sandwiches.length + " sandwiches!");
Rule Details
This rule is aimed at discouraging the use of var
and encouraging the use of const
or let
instead.
Examples
Examples of incorrect code for this rule:
/*eslint no-var: "error"*/
var x = "y";
var CONFIG = {};
Examples of correct code for this rule:
/*eslint no-var: "error"*/
/*eslint-env es6*/
let x = "y";
const CONFIG = {};
When Not To Use It
In addition to non-ES6 environments, existing JavaScript projects that are beginning to introduce ES6 into their
codebase may not want to apply this rule if the cost of migrating from var
to let
is too costly.
Source: http://eslint.org/docs/rules/
Expected indentation of 2 spaces but found 4. Open
Label.prototype.show = function(){
- Read upRead up
- Exclude checks
enforce consistent indentation (indent)
There are several common guidelines which require specific indentation of nested blocks and statements, like:
function hello(indentSize, type) {
if (indentSize === 4 && type !== 'tab') {
console.log('Each next indentation will increase on 4 spaces');
}
}
These are the most common scenarios recommended in different style guides:
- Two spaces, not longer and no tabs: Google, npm, Node.js, Idiomatic, Felix
- Tabs: jQuery
- Four spaces: Crockford
Rule Details
This rule enforces a consistent indentation style. The default style is 4 spaces
.
Options
This rule has a mixed option:
For example, for 2-space indentation:
{
"indent": ["error", 2]
}
Or for tabbed indentation:
{
"indent": ["error", "tab"]
}
Examples of incorrect code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
This rule has an object option:
-
"SwitchCase"
(default: 0) enforces indentation level forcase
clauses inswitch
statements -
"VariableDeclarator"
(default: 1) enforces indentation level forvar
declarators; can also take an object to define separate rules forvar
,let
andconst
declarations. -
"outerIIFEBody"
(default: 1) enforces indentation level for file-level IIFEs. -
"MemberExpression"
(off by default) enforces indentation level for multi-line property chains (except in variable declarations and assignments) -
"FunctionDeclaration"
takes an object to define rules for function declarations.-
parameters
(off by default) enforces indentation level for parameters in a function declaration. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the declaration must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function declaration.
-
-
"FunctionExpression"
takes an object to define rules for function expressions.-
parameters
(off by default) enforces indentation level for parameters in a function expression. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the expression must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function expression.
-
-
"CallExpression"
takes an object to define rules for function call expressions.-
arguments
(off by default) enforces indentation level for arguments in a call expression. This can either be a number indicating indentation level, or the string"first"
indicating that all arguments of the expression must be aligned with the first argument.
-
-
"ArrayExpression"
(default: 1) enforces indentation level for elements in arrays. It can also be set to the string"first"
, indicating that all the elements in the array should be aligned with the first element. -
"ObjectExpression"
(default: 1) enforces indentation level for properties in objects. It can be set to the string"first"
, indicating that all properties in the object should be aligned with the first property.
Level of indentation denotes the multiple of the indent specified. Example:
- Indent of 4 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 8 spaces. - Indent of 2 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 4 spaces. - Indent of 2 spaces with
VariableDeclarator
set to{"var": 2, "let": 2, "const": 3}
will indent the multi-line variable declarations with 4 spaces forvar
andlet
, 6 spaces forconst
statements. - Indent of tab with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 2 tabs. - Indent of 2 spaces with
SwitchCase
set to0
will not indentcase
clauses with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to1
will indentcase
clauses with 2 spaces with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to2
will indentcase
clauses with 4 spaces with respect toswitch
statements. - Indent of tab with
SwitchCase
set to2
will indentcase
clauses with 2 tabs with respect toswitch
statements. - Indent of 2 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 2 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 2 spaces. - Indent of 2 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 4 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 8 spaces.
tab
Examples of incorrect code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
/*tab*/b=c;
/*tab*/function foo(d) {
/*tab*//*tab*/e=f;
/*tab*/}
}
SwitchCase
Examples of incorrect code for this rule with the 2, { "SwitchCase": 1 }
options:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
Examples of correct code for this rule with the 2, { "SwitchCase": 1 }
option:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
VariableDeclarator
Examples of incorrect code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 2 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 2 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
outerIIFEBody
Examples of incorrect code for this rule with the options 2, { "outerIIFEBody": 0 }
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
Examples of correct code for this rule with the options 2, {"outerIIFEBody": 0}
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
MemberExpression
Examples of incorrect code for this rule with the 2, { "MemberExpression": 1 }
options:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz()
Examples of correct code for this rule with the 2, { "MemberExpression": 1 }
option:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz();
// Any indentation is permitted in variable declarations and assignments.
var bip = aardvark.badger
.coyote;
FunctionDeclaration
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
FunctionExpression
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
CallExpression
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
ArrayExpression
Examples of incorrect code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of incorrect code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
ObjectExpression
Examples of incorrect code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of correct code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of incorrect code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Examples of correct code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Compatibility
-
JSHint:
indent
- JSCS: validateIndentation Source: http://eslint.org/docs/rules/
Unexpected function expression. Open
tinymce.PluginManager.add('placeholder', function(editor) {
- Read upRead up
- Exclude checks
Suggest using arrow functions as callbacks. (prefer-arrow-callback)
Arrow functions are suited to callbacks, because:
-
this
keywords in arrow functions bind to the upper scope's. - The notation of the arrow function is shorter than function expression's.
Rule Details
This rule is aimed to flag usage of function expressions in an argument list.
The following patterns are considered problems:
/*eslint prefer-arrow-callback: "error"*/
foo(function(a) { return a; });
foo(function() { return this.a; }.bind(this));
The following patterns are not considered problems:
/*eslint prefer-arrow-callback: "error"*/
/*eslint-env es6*/
foo(a => a);
foo(function*() { yield; });
// this is not a callback.
var foo = function foo(a) { return a; };
// using `this` without `.bind(this)`.
foo(function() { return this.a; });
// recursively.
foo(function bar(n) { return n && n + bar(n - 1); });
Options
This rule takes one optional argument, an object which is an options object.
allowNamedFunctions
This is a boolean
option and it is false
by default. When set to true
, the rule doesn't warn on named functions used as callbacks.
Examples of correct code for the { "allowNamedFunctions": true }
option:
/*eslint prefer-arrow-callback: ["error", { "allowNamedFunctions": true }]*/
foo(function bar() {});
allowUnboundThis
This is a boolean
option and it is true
by default. When set to false
, this option allows the use of this
without restriction and checks for dynamically assigned this
values such as when using Array.prototype.map
with a context
argument. Normally, the rule will flag the use of this
whenever a function does not use bind()
to specify the value of this
constantly.
Examples of incorrect code for the { "allowUnboundThis": false }
option:
/*eslint prefer-arrow-callback: ["error", { "allowUnboundThis": false }]*/
/*eslint-env es6*/
foo(function() { this.a; });
foo(function() { (() => this); });
someArray.map(function (itm) { return this.doSomething(itm); }, someObject);
When Not To Use It
This rule should not be used in ES3/5 environments.
In ES2015 (ES6) or later, if you don't want to be notified about function expressions in an argument list, you can safely disable this rule. Source: http://eslint.org/docs/rules/
Missing space before opening brace. Open
var Label = function(){
- Read upRead up
- Exclude checks
Require Or Disallow Space Before Blocks (space-before-blocks)
Consistency is an important part of any style guide. While it is a personal preference where to put the opening brace of blocks, it should be consistent across a whole project. Having an inconsistent style distracts the reader from seeing the important parts of the code.
Rule Details
This rule will enforce consistency of spacing before blocks. It is only applied on blocks that don’t begin on a new line.
- This rule ignores spacing which is between
=>
and a block. The spacing is handled by thearrow-spacing
rule. - This rule ignores spacing which is between a keyword and a block. The spacing is handled by the
keyword-spacing
rule.
Options
This rule takes one argument. If it is "always"
then blocks must always have at least one preceding space. If "never"
then all blocks should never have any preceding space. If different spacing is desired for function
blocks, keyword blocks and classes, an optional configuration object can be passed as the rule argument to
configure the cases separately.
( e.g. { "functions": "never", "keywords": "always", "classes": "always" }
)
The default is "always"
.
"always"
Examples of incorrect code for this rule with the "always" option:
/*eslint space-before-blocks: "error"*/
if (a){
b();
}
function a(){}
for (;;){
b();
}
try {} catch(a){}
class Foo{
constructor(){}
}
Examples of correct code for this rule with the "always" option:
/*eslint space-before-blocks: "error"*/
if (a) {
b();
}
if (a) {
b();
} else{ /*no error. this is checked by `keyword-spacing` rule.*/
c();
}
function a() {}
for (;;) {
b();
}
try {} catch(a) {}
"never"
Examples of incorrect code for this rule with the "never" option:
/*eslint space-before-blocks: ["error", "never"]*/
if (a) {
b();
}
function a() {}
for (;;) {
b();
}
try {} catch(a) {}
Examples of correct code for this rule with the "never" option:
/*eslint space-before-blocks: ["error", "never"]*/
if (a){
b();
}
function a(){}
for (;;){
b();
}
try{} catch(a){}
class Foo{
constructor(){}
}
Examples of incorrect code for this rule when configured { "functions": "never", "keywords": "always", "classes": "never" }
:
/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "always", "classes": "never" }]*/
/*eslint-env es6*/
function a() {}
try {} catch(a){}
class Foo{
constructor() {}
}
Examples of correct code for this rule when configured { "functions": "never", "keywords": "always", "classes": "never" }
:
/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "always", "classes": "never" }]*/
/*eslint-env es6*/
for (;;) {
// ...
}
describe(function(){
// ...
});
class Foo {
constructor(){}
}
Examples of incorrect code for this rule when configured { "functions": "always", "keywords": "never", "classes": "never" }
:
/*eslint space-before-blocks: ["error", { "functions": "always", "keywords": "never", "classes": "never" }]*/
/*eslint-env es6*/
function a(){}
try {} catch(a) {}
class Foo {
constructor(){}
}
Examples of correct code for this rule when configured { "functions": "always", "keywords": "never", "classes": "never" }
:
/*eslint space-before-blocks: ["error", { "functions": "always", "keywords": "never", "classes": "never" }]*/
/*eslint-env es6*/
if (a){
b();
}
var a = function() {}
class Foo{
constructor() {}
}
Examples of incorrect code for this rule when configured { "functions": "never", "keywords": "never", "classes": "always" }
:
/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "never", "classes": "always" }]*/
/*eslint-env es6*/
class Foo{
constructor(){}
}
Examples of correct code for this rule when configured { "functions": "never", "keywords": "never", "classes": "always" }
:
/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "never", "classes": "always" }]*/
/*eslint-env es6*/
class Foo {
constructor(){}
}
When Not To Use It
You can turn this rule off if you are not concerned with the consistency of spacing before blocks.
Related Rules
- [keyword-spacing](keyword-spacing.md)
- [arrow-spacing](arrow-spacing.md)
- [brace-style](brace-style.md) Source: http://eslint.org/docs/rules/
Strings must use singlequote. Open
var placeholder_text = editor.getElement().getAttribute("placeholder") || editor.settings.placeholder;
- Read upRead up
- Exclude checks
enforce the consistent use of either backticks, double, or single quotes (quotes)
JavaScript allows you to define strings in one of three ways: double quotes, single quotes, and backticks (as of ECMAScript 6). For example:
/*eslint-env es6*/
var double = "double";
var single = 'single';
var backtick = `backtick`; // ES6 only
Each of these lines creates a string and, in some cases, can be used interchangeably. The choice of how to define strings in a codebase is a stylistic one outside of template literals (which allow embedded of expressions to be interpreted).
Many codebases require strings to be defined in a consistent manner.
Rule Details
This rule enforces the consistent use of either backticks, double, or single quotes.
Options
This rule has two options, a string option and an object option.
String option:
-
"double"
(default) requires the use of double quotes wherever possible -
"single"
requires the use of single quotes wherever possible -
"backtick"
requires the use of backticks wherever possible
Object option:
-
"avoidEscape": true
allows strings to use single-quotes or double-quotes so long as the string contains a quote that would have to be escaped otherwise -
"allowTemplateLiterals": true
allows strings to use backticks
Deprecated: The object property avoid-escape
is deprecated; please use the object property avoidEscape
instead.
double
Examples of incorrect code for this rule with the default "double"
option:
/*eslint quotes: ["error", "double"]*/
var single = 'single';
var unescaped = 'a string containing "double" quotes';
Examples of correct code for this rule with the default "double"
option:
/*eslint quotes: ["error", "double"]*/
/*eslint-env es6*/
var double = "double";
var backtick = `back\ntick`; // backticks are allowed due to newline
var backtick = tag`backtick`; // backticks are allowed due to tag
single
Examples of incorrect code for this rule with the "single"
option:
/*eslint quotes: ["error", "single"]*/
var double = "double";
var unescaped = "a string containing 'single' quotes";
Examples of correct code for this rule with the "single"
option:
/*eslint quotes: ["error", "single"]*/
/*eslint-env es6*/
var single = 'single';
var backtick = `back${x}tick`; // backticks are allowed due to substitution
backticks
Examples of incorrect code for this rule with the "backtick"
option:
/*eslint quotes: ["error", "backtick"]*/
var single = 'single';
var double = "double";
var unescaped = 'a string containing `backticks`';
Examples of correct code for this rule with the "backtick"
option:
/*eslint quotes: ["error", "backtick"]*/
/*eslint-env es6*/
var backtick = `backtick`;
avoidEscape
Examples of additional correct code for this rule with the "double", { "avoidEscape": true }
options:
/*eslint quotes: ["error", "double", { "avoidEscape": true }]*/
var single = 'a string containing "double" quotes';
Examples of additional correct code for this rule with the "single", { "avoidEscape": true }
options:
/*eslint quotes: ["error", "single", { "avoidEscape": true }]*/
var double = "a string containing 'single' quotes";
Examples of additional correct code for this rule with the "backtick", { "avoidEscape": true }
options:
/*eslint quotes: ["error", "backtick", { "avoidEscape": true }]*/
var double = "a string containing `backtick` quotes"
allowTemplateLiterals
Examples of additional correct code for this rule with the "double", { "allowTemplateLiterals": true }
options:
/*eslint quotes: ["error", "double", { "allowTemplateLiterals": true }]*/
var double = "double";
var double = `double`;
Examples of additional correct code for this rule with the "single", { "allowTemplateLiterals": true }
options:
/*eslint quotes: ["error", "single", { "allowTemplateLiterals": true }]*/
var single = 'single';
var single = `single`;
When Not To Use It
If you do not need consistency in your string styles, you can safely disable this rule. Source: http://eslint.org/docs/rules/
A space is required before '}'. Open
var placeholder_attrs = editor.settings.placeholder_attrs || {style: {position: 'absolute', top:'5px', left:0, color: '#888', padding: '1%', width:'98%', overflow: 'hidden', 'white-space': 'pre-wrap'} };
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enforce consistent spacing inside braces (object-curly-spacing)
While formatting preferences are very personal, a number of style guides require or disallow spaces between curly braces in the following situations:
// simple object literals
var obj = { foo: "bar" };
// nested object literals
var obj = { foo: { zoo: "bar" } };
// destructuring assignment (EcmaScript 6)
var { x, y } = y;
// import/export declarations (EcmaScript 6)
import { foo } from "bar";
export { foo };
Rule Details
This rule enforce consistent spacing inside braces of object literals, destructuring assignments, and import/export specifiers.
Options
This rule has two options, a string option and an object option.
String option:
-
"never"
(default) disallows spacing inside of braces -
"always"
requires spacing inside of braces (except{}
)
Object option:
-
"arraysInObjects": true
requires spacing inside of braces of objects beginning and/or ending with an array element (applies when the first option is set tonever
) -
"arraysInObjects": false
disallows spacing inside of braces of objects beginning and/or ending with an array element (applies when the first option is set toalways
) -
"objectsInObjects": true
requires spacing inside of braces of objects beginning and/or ending with an object element (applies when the first option is set tonever
) -
"objectsInObjects": false
disallows spacing inside of braces of objects beginning and/or ending with an object element (applies when the first option is set toalways
)
never
Examples of incorrect code for this rule with the default "never"
option:
/*eslint object-curly-spacing: ["error", "never"]*/
var obj = { 'foo': 'bar' };
var obj = {'foo': 'bar' };
var obj = { baz: {'foo': 'qux'}, bar};
var obj = {baz: { 'foo': 'qux'}, bar};
var {x } = y;
import { foo } from 'bar';
Examples of correct code for this rule with the default "never"
option:
/*eslint object-curly-spacing: ["error", "never"]*/
var obj = {'foo': 'bar'};
var obj = {'foo': {'bar': 'baz'}, 'qux': 'quxx'};
var obj = {
'foo': 'bar'
};
var obj = {'foo': 'bar'
};
var obj = {
'foo':'bar'};
var obj = {};
var {x} = y;
import {foo} from 'bar';
always
Examples of incorrect code for this rule with the "always"
option:
/*eslint object-curly-spacing: ["error", "always"]*/
var obj = {'foo': 'bar'};
var obj = {'foo': 'bar' };
var obj = { baz: {'foo': 'qux'}, bar};
var obj = {baz: { 'foo': 'qux' }, bar};
var obj = {'foo': 'bar'
};
var obj = {
'foo':'bar'};
var {x} = y;
import {foo } from 'bar';
Examples of correct code for this rule with the "always"
option:
/*eslint object-curly-spacing: ["error", "always"]*/
var obj = {};
var obj = { 'foo': 'bar' };
var obj = { 'foo': { 'bar': 'baz' }, 'qux': 'quxx' };
var obj = {
'foo': 'bar'
};
var { x } = y;
import { foo } from 'bar';
arraysInObjects
Examples of additional correct code for this rule with the "never", { "arraysInObjects": true }
options:
/*eslint object-curly-spacing: ["error", "never", { "arraysInObjects": true }]*/
var obj = {"foo": [ 1, 2 ] };
var obj = {"foo": [ "baz", "bar" ] };
Examples of additional correct code for this rule with the "always", { "arraysInObjects": false }
options:
/*eslint object-curly-spacing: ["error", "always", { "arraysInObjects": false }]*/
var obj = { "foo": [ 1, 2 ]};
var obj = { "foo": [ "baz", "bar" ]};
objectsInObjects
Examples of additional correct code for this rule with the "never", { "objectsInObjects": true }
options:
/*eslint object-curly-spacing: ["error", "never", { "objectsInObjects": true }]*/
var obj = {"foo": {"baz": 1, "bar": 2} };
Examples of additional correct code for this rule with the "always", { "objectsInObjects": false }
options:
/*eslint object-curly-spacing: ["error", "always", { "objectsInObjects": false }]*/
var obj = { "foo": { "baz": 1, "bar": 2 }};
When Not To Use It
You can turn this rule off if you are not concerned with the consistency of spacing between curly braces.
Related Rules
- [comma-spacing](comma-spacing.md)
- [space-in-parens](space-in-parens.md) Source: http://eslint.org/docs/rules/
There should be no spaces inside this paren. Open
this.el = tinymce.DOM.add( contentAreaContainer, editor.settings.placeholder_tag || "label", placeholder_attrs, placeholder_text );
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Disallow or enforce spaces inside of parentheses (space-in-parens)
Some style guides require or disallow spaces inside of parentheses:
foo( 'bar' );
var x = ( 1 + 2 ) * 3;
foo('bar');
var x = (1 + 2) * 3;
Rule Details
This rule will enforce consistency of spacing directly inside of parentheses, by disallowing or requiring one or more spaces to the right of (
and to the left of )
. In either case, ()
will still be allowed.
Options
There are two options for this rule:
-
"never"
(default) enforces zero spaces inside of parentheses -
"always"
enforces a space inside of parentheses
Depending on your coding conventions, you can choose either option by specifying it in your configuration:
"space-in-parens": ["error", "always"]
"never"
Examples of incorrect code for this rule with the default "never"
option:
/*eslint space-in-parens: ["error", "never"]*/
foo( 'bar');
foo('bar' );
foo( 'bar' );
var foo = ( 1 + 2 ) * 3;
( function () { return 'bar'; }() );
Examples of correct code for this rule with the default "never"
option:
/*eslint space-in-parens: ["error", "never"]*/
foo();
foo('bar');
var foo = (1 + 2) * 3;
(function () { return 'bar'; }());
"always"
Examples of incorrect code for this rule with the "always"
option:
/*eslint space-in-parens: ["error", "always"]*/
foo( 'bar');
foo('bar' );
foo('bar');
var foo = (1 + 2) * 3;
(function () { return 'bar'; }());
Examples of correct code for this rule with the "always"
option:
/*eslint space-in-parens: ["error", "always"]*/
foo();
foo( 'bar' );
var foo = ( 1 + 2 ) * 3;
( function () { return 'bar'; }() );
Exceptions
An object literal may be used as a third array item to specify exceptions, with the key "exceptions"
and an array as the value. These exceptions work in the context of the first option. That is, if "always"
is set to enforce spacing, then any "exception" will disallow spacing. Conversely, if "never"
is set to disallow spacing, then any "exception" will enforce spacing.
The following exceptions are available: ["{}", "[]", "()", "empty"]
.
Examples of incorrect code for this rule with the "never", { "exceptions": ["{}"] }
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["{}"] }]*/
foo({bar: 'baz'});
foo(1, {bar: 'baz'});
Examples of correct code for this rule with the "never", { "exceptions": ["{}"] }
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["{}"] }]*/
foo( {bar: 'baz'} );
foo(1, {bar: 'baz'} );
Examples of incorrect code for this rule with the "always", { "exceptions": ["{}"] }
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["{}"] }]*/
foo( {bar: 'baz'} );
foo( 1, {bar: 'baz'} );
Examples of correct code for this rule with the "always", { "exceptions": ["{}"] }
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["{}"] }]*/
foo({bar: 'baz'});
foo( 1, {bar: 'baz'});
Examples of incorrect code for this rule with the "never", { "exceptions": ["[]"] }
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["[]"] }]*/
foo([bar, baz]);
foo([bar, baz], 1);
Examples of correct code for this rule with the "never", { "exceptions": ["[]"] }
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["[]"] }]*/
foo( [bar, baz] );
foo( [bar, baz], 1);
Examples of incorrect code for this rule with the "always", { "exceptions": ["[]"] }
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["[]"] }]*/
foo( [bar, baz] );
foo( [bar, baz], 1 );
Examples of correct code for this rule with the "always", { "exceptions": ["[]"] }
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["[]"] }]*/
foo([bar, baz]);
foo([bar, baz], 1 );
Examples of incorrect code for this rule with the "never", { "exceptions": ["()"] }]
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["()"] }]*/
foo((1 + 2));
foo((1 + 2), 1);
Examples of correct code for this rule with the "never", { "exceptions": ["()"] }]
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["()"] }]*/
foo( (1 + 2) );
foo( (1 + 2), 1);
Examples of incorrect code for this rule with the "always", { "exceptions": ["()"] }]
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["()"] }]*/
foo( ( 1 + 2 ) );
foo( ( 1 + 2 ), 1 );
Examples of correct code for this rule with the "always", { "exceptions": ["()"] }]
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["()"] }]*/
foo(( 1 + 2 ));
foo(( 1 + 2 ), 1 );
The "empty"
exception concerns empty parentheses, and works the same way as the other exceptions, inverting the first option.
Example of incorrect code for this rule with the "never", { "exceptions": ["empty"] }]
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["empty"] }]*/
foo();
Example of correct code for this rule with the "never", { "exceptions": ["empty"] }]
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["empty"] }]*/
foo( );
Example of incorrect code for this rule with the "always", { "exceptions": ["empty"] }]
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["empty"] }]*/
foo( );
Example of correct code for this rule with the "always", { "exceptions": ["empty"] }]
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["empty"] }]*/
foo();
You can include multiple entries in the "exceptions"
array.
Examples of incorrect code for this rule with the "always", { "exceptions": ["{}", "[]"] }]
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["{}", "[]"] }]*/
bar( {bar:'baz'} );
baz( 1, [1,2] );
foo( {bar: 'baz'}, [1, 2] );
Examples of correct code for this rule with the "always", { "exceptions": ["{}", "[]"] }]
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["{}", "[]"] }]*/
bar({bar:'baz'});
baz( 1, [1,2]);
foo({bar: 'baz'}, [1, 2]);
When Not To Use It
You can turn this rule off if you are not concerned with the consistency of spacing between parentheses.
Related Rules
- [space-in-brackets](space-in-brackets.md) (deprecated) Source: http://eslint.org/docs/rules/
Strings must use singlequote. Open
this.el = tinymce.DOM.add( contentAreaContainer, editor.settings.placeholder_tag || "label", placeholder_attrs, placeholder_text );
- Read upRead up
- Exclude checks
enforce the consistent use of either backticks, double, or single quotes (quotes)
JavaScript allows you to define strings in one of three ways: double quotes, single quotes, and backticks (as of ECMAScript 6). For example:
/*eslint-env es6*/
var double = "double";
var single = 'single';
var backtick = `backtick`; // ES6 only
Each of these lines creates a string and, in some cases, can be used interchangeably. The choice of how to define strings in a codebase is a stylistic one outside of template literals (which allow embedded of expressions to be interpreted).
Many codebases require strings to be defined in a consistent manner.
Rule Details
This rule enforces the consistent use of either backticks, double, or single quotes.
Options
This rule has two options, a string option and an object option.
String option:
-
"double"
(default) requires the use of double quotes wherever possible -
"single"
requires the use of single quotes wherever possible -
"backtick"
requires the use of backticks wherever possible
Object option:
-
"avoidEscape": true
allows strings to use single-quotes or double-quotes so long as the string contains a quote that would have to be escaped otherwise -
"allowTemplateLiterals": true
allows strings to use backticks
Deprecated: The object property avoid-escape
is deprecated; please use the object property avoidEscape
instead.
double
Examples of incorrect code for this rule with the default "double"
option:
/*eslint quotes: ["error", "double"]*/
var single = 'single';
var unescaped = 'a string containing "double" quotes';
Examples of correct code for this rule with the default "double"
option:
/*eslint quotes: ["error", "double"]*/
/*eslint-env es6*/
var double = "double";
var backtick = `back\ntick`; // backticks are allowed due to newline
var backtick = tag`backtick`; // backticks are allowed due to tag
single
Examples of incorrect code for this rule with the "single"
option:
/*eslint quotes: ["error", "single"]*/
var double = "double";
var unescaped = "a string containing 'single' quotes";
Examples of correct code for this rule with the "single"
option:
/*eslint quotes: ["error", "single"]*/
/*eslint-env es6*/
var single = 'single';
var backtick = `back${x}tick`; // backticks are allowed due to substitution
backticks
Examples of incorrect code for this rule with the "backtick"
option:
/*eslint quotes: ["error", "backtick"]*/
var single = 'single';
var double = "double";
var unescaped = 'a string containing `backticks`';
Examples of correct code for this rule with the "backtick"
option:
/*eslint quotes: ["error", "backtick"]*/
/*eslint-env es6*/
var backtick = `backtick`;
avoidEscape
Examples of additional correct code for this rule with the "double", { "avoidEscape": true }
options:
/*eslint quotes: ["error", "double", { "avoidEscape": true }]*/
var single = 'a string containing "double" quotes';
Examples of additional correct code for this rule with the "single", { "avoidEscape": true }
options:
/*eslint quotes: ["error", "single", { "avoidEscape": true }]*/
var double = "a string containing 'single' quotes";
Examples of additional correct code for this rule with the "backtick", { "avoidEscape": true }
options:
/*eslint quotes: ["error", "backtick", { "avoidEscape": true }]*/
var double = "a string containing `backtick` quotes"
allowTemplateLiterals
Examples of additional correct code for this rule with the "double", { "allowTemplateLiterals": true }
options:
/*eslint quotes: ["error", "double", { "allowTemplateLiterals": true }]*/
var double = "double";
var double = `double`;
Examples of additional correct code for this rule with the "single", { "allowTemplateLiterals": true }
options:
/*eslint quotes: ["error", "single", { "allowTemplateLiterals": true }]*/
var single = 'single';
var single = `single`;
When Not To Use It
If you do not need consistency in your string styles, you can safely disable this rule. Source: http://eslint.org/docs/rules/
Expected indentation of 2 spaces but found 4. Open
editor.on('init', function() {
- Read upRead up
- Exclude checks
enforce consistent indentation (indent)
There are several common guidelines which require specific indentation of nested blocks and statements, like:
function hello(indentSize, type) {
if (indentSize === 4 && type !== 'tab') {
console.log('Each next indentation will increase on 4 spaces');
}
}
These are the most common scenarios recommended in different style guides:
- Two spaces, not longer and no tabs: Google, npm, Node.js, Idiomatic, Felix
- Tabs: jQuery
- Four spaces: Crockford
Rule Details
This rule enforces a consistent indentation style. The default style is 4 spaces
.
Options
This rule has a mixed option:
For example, for 2-space indentation:
{
"indent": ["error", 2]
}
Or for tabbed indentation:
{
"indent": ["error", "tab"]
}
Examples of incorrect code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
This rule has an object option:
-
"SwitchCase"
(default: 0) enforces indentation level forcase
clauses inswitch
statements -
"VariableDeclarator"
(default: 1) enforces indentation level forvar
declarators; can also take an object to define separate rules forvar
,let
andconst
declarations. -
"outerIIFEBody"
(default: 1) enforces indentation level for file-level IIFEs. -
"MemberExpression"
(off by default) enforces indentation level for multi-line property chains (except in variable declarations and assignments) -
"FunctionDeclaration"
takes an object to define rules for function declarations.-
parameters
(off by default) enforces indentation level for parameters in a function declaration. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the declaration must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function declaration.
-
-
"FunctionExpression"
takes an object to define rules for function expressions.-
parameters
(off by default) enforces indentation level for parameters in a function expression. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the expression must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function expression.
-
-
"CallExpression"
takes an object to define rules for function call expressions.-
arguments
(off by default) enforces indentation level for arguments in a call expression. This can either be a number indicating indentation level, or the string"first"
indicating that all arguments of the expression must be aligned with the first argument.
-
-
"ArrayExpression"
(default: 1) enforces indentation level for elements in arrays. It can also be set to the string"first"
, indicating that all the elements in the array should be aligned with the first element. -
"ObjectExpression"
(default: 1) enforces indentation level for properties in objects. It can be set to the string"first"
, indicating that all properties in the object should be aligned with the first property.
Level of indentation denotes the multiple of the indent specified. Example:
- Indent of 4 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 8 spaces. - Indent of 2 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 4 spaces. - Indent of 2 spaces with
VariableDeclarator
set to{"var": 2, "let": 2, "const": 3}
will indent the multi-line variable declarations with 4 spaces forvar
andlet
, 6 spaces forconst
statements. - Indent of tab with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 2 tabs. - Indent of 2 spaces with
SwitchCase
set to0
will not indentcase
clauses with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to1
will indentcase
clauses with 2 spaces with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to2
will indentcase
clauses with 4 spaces with respect toswitch
statements. - Indent of tab with
SwitchCase
set to2
will indentcase
clauses with 2 tabs with respect toswitch
statements. - Indent of 2 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 2 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 2 spaces. - Indent of 2 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 4 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 8 spaces.
tab
Examples of incorrect code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
/*tab*/b=c;
/*tab*/function foo(d) {
/*tab*//*tab*/e=f;
/*tab*/}
}
SwitchCase
Examples of incorrect code for this rule with the 2, { "SwitchCase": 1 }
options:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
Examples of correct code for this rule with the 2, { "SwitchCase": 1 }
option:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
VariableDeclarator
Examples of incorrect code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 2 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 2 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
outerIIFEBody
Examples of incorrect code for this rule with the options 2, { "outerIIFEBody": 0 }
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
Examples of correct code for this rule with the options 2, {"outerIIFEBody": 0}
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
MemberExpression
Examples of incorrect code for this rule with the 2, { "MemberExpression": 1 }
options:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz()
Examples of correct code for this rule with the 2, { "MemberExpression": 1 }
option:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz();
// Any indentation is permitted in variable declarations and assignments.
var bip = aardvark.badger
.coyote;
FunctionDeclaration
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
FunctionExpression
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
CallExpression
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
ArrayExpression
Examples of incorrect code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of incorrect code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
ObjectExpression
Examples of incorrect code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of correct code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of incorrect code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Examples of correct code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Compatibility
-
JSHint:
indent
- JSCS: validateIndentation Source: http://eslint.org/docs/rules/
Expected indentation of 6 spaces but found 8. Open
var placeholder_attrs = editor.settings.placeholder_attrs || {style: {position: 'absolute', top:'5px', left:0, color: '#888', padding: '1%', width:'98%', overflow: 'hidden', 'white-space': 'pre-wrap'} };
- Read upRead up
- Exclude checks
enforce consistent indentation (indent)
There are several common guidelines which require specific indentation of nested blocks and statements, like:
function hello(indentSize, type) {
if (indentSize === 4 && type !== 'tab') {
console.log('Each next indentation will increase on 4 spaces');
}
}
These are the most common scenarios recommended in different style guides:
- Two spaces, not longer and no tabs: Google, npm, Node.js, Idiomatic, Felix
- Tabs: jQuery
- Four spaces: Crockford
Rule Details
This rule enforces a consistent indentation style. The default style is 4 spaces
.
Options
This rule has a mixed option:
For example, for 2-space indentation:
{
"indent": ["error", 2]
}
Or for tabbed indentation:
{
"indent": ["error", "tab"]
}
Examples of incorrect code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
This rule has an object option:
-
"SwitchCase"
(default: 0) enforces indentation level forcase
clauses inswitch
statements -
"VariableDeclarator"
(default: 1) enforces indentation level forvar
declarators; can also take an object to define separate rules forvar
,let
andconst
declarations. -
"outerIIFEBody"
(default: 1) enforces indentation level for file-level IIFEs. -
"MemberExpression"
(off by default) enforces indentation level for multi-line property chains (except in variable declarations and assignments) -
"FunctionDeclaration"
takes an object to define rules for function declarations.-
parameters
(off by default) enforces indentation level for parameters in a function declaration. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the declaration must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function declaration.
-
-
"FunctionExpression"
takes an object to define rules for function expressions.-
parameters
(off by default) enforces indentation level for parameters in a function expression. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the expression must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function expression.
-
-
"CallExpression"
takes an object to define rules for function call expressions.-
arguments
(off by default) enforces indentation level for arguments in a call expression. This can either be a number indicating indentation level, or the string"first"
indicating that all arguments of the expression must be aligned with the first argument.
-
-
"ArrayExpression"
(default: 1) enforces indentation level for elements in arrays. It can also be set to the string"first"
, indicating that all the elements in the array should be aligned with the first element. -
"ObjectExpression"
(default: 1) enforces indentation level for properties in objects. It can be set to the string"first"
, indicating that all properties in the object should be aligned with the first property.
Level of indentation denotes the multiple of the indent specified. Example:
- Indent of 4 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 8 spaces. - Indent of 2 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 4 spaces. - Indent of 2 spaces with
VariableDeclarator
set to{"var": 2, "let": 2, "const": 3}
will indent the multi-line variable declarations with 4 spaces forvar
andlet
, 6 spaces forconst
statements. - Indent of tab with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 2 tabs. - Indent of 2 spaces with
SwitchCase
set to0
will not indentcase
clauses with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to1
will indentcase
clauses with 2 spaces with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to2
will indentcase
clauses with 4 spaces with respect toswitch
statements. - Indent of tab with
SwitchCase
set to2
will indentcase
clauses with 2 tabs with respect toswitch
statements. - Indent of 2 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 2 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 2 spaces. - Indent of 2 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 4 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 8 spaces.
tab
Examples of incorrect code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
/*tab*/b=c;
/*tab*/function foo(d) {
/*tab*//*tab*/e=f;
/*tab*/}
}
SwitchCase
Examples of incorrect code for this rule with the 2, { "SwitchCase": 1 }
options:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
Examples of correct code for this rule with the 2, { "SwitchCase": 1 }
option:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
VariableDeclarator
Examples of incorrect code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 2 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 2 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
outerIIFEBody
Examples of incorrect code for this rule with the options 2, { "outerIIFEBody": 0 }
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
Examples of correct code for this rule with the options 2, {"outerIIFEBody": 0}
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
MemberExpression
Examples of incorrect code for this rule with the 2, { "MemberExpression": 1 }
options:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz()
Examples of correct code for this rule with the 2, { "MemberExpression": 1 }
option:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz();
// Any indentation is permitted in variable declarations and assignments.
var bip = aardvark.badger
.coyote;
FunctionDeclaration
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
FunctionExpression
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
CallExpression
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
ArrayExpression
Examples of incorrect code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of incorrect code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
ObjectExpression
Examples of incorrect code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of correct code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of incorrect code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Examples of correct code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Compatibility
-
JSHint:
indent
- JSCS: validateIndentation Source: http://eslint.org/docs/rules/
There should be no spaces inside this paren. Open
tinymce.DOM.setStyle( this.el, 'display', 'none' );
- Read upRead up
- Exclude checks
Disallow or enforce spaces inside of parentheses (space-in-parens)
Some style guides require or disallow spaces inside of parentheses:
foo( 'bar' );
var x = ( 1 + 2 ) * 3;
foo('bar');
var x = (1 + 2) * 3;
Rule Details
This rule will enforce consistency of spacing directly inside of parentheses, by disallowing or requiring one or more spaces to the right of (
and to the left of )
. In either case, ()
will still be allowed.
Options
There are two options for this rule:
-
"never"
(default) enforces zero spaces inside of parentheses -
"always"
enforces a space inside of parentheses
Depending on your coding conventions, you can choose either option by specifying it in your configuration:
"space-in-parens": ["error", "always"]
"never"
Examples of incorrect code for this rule with the default "never"
option:
/*eslint space-in-parens: ["error", "never"]*/
foo( 'bar');
foo('bar' );
foo( 'bar' );
var foo = ( 1 + 2 ) * 3;
( function () { return 'bar'; }() );
Examples of correct code for this rule with the default "never"
option:
/*eslint space-in-parens: ["error", "never"]*/
foo();
foo('bar');
var foo = (1 + 2) * 3;
(function () { return 'bar'; }());
"always"
Examples of incorrect code for this rule with the "always"
option:
/*eslint space-in-parens: ["error", "always"]*/
foo( 'bar');
foo('bar' );
foo('bar');
var foo = (1 + 2) * 3;
(function () { return 'bar'; }());
Examples of correct code for this rule with the "always"
option:
/*eslint space-in-parens: ["error", "always"]*/
foo();
foo( 'bar' );
var foo = ( 1 + 2 ) * 3;
( function () { return 'bar'; }() );
Exceptions
An object literal may be used as a third array item to specify exceptions, with the key "exceptions"
and an array as the value. These exceptions work in the context of the first option. That is, if "always"
is set to enforce spacing, then any "exception" will disallow spacing. Conversely, if "never"
is set to disallow spacing, then any "exception" will enforce spacing.
The following exceptions are available: ["{}", "[]", "()", "empty"]
.
Examples of incorrect code for this rule with the "never", { "exceptions": ["{}"] }
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["{}"] }]*/
foo({bar: 'baz'});
foo(1, {bar: 'baz'});
Examples of correct code for this rule with the "never", { "exceptions": ["{}"] }
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["{}"] }]*/
foo( {bar: 'baz'} );
foo(1, {bar: 'baz'} );
Examples of incorrect code for this rule with the "always", { "exceptions": ["{}"] }
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["{}"] }]*/
foo( {bar: 'baz'} );
foo( 1, {bar: 'baz'} );
Examples of correct code for this rule with the "always", { "exceptions": ["{}"] }
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["{}"] }]*/
foo({bar: 'baz'});
foo( 1, {bar: 'baz'});
Examples of incorrect code for this rule with the "never", { "exceptions": ["[]"] }
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["[]"] }]*/
foo([bar, baz]);
foo([bar, baz], 1);
Examples of correct code for this rule with the "never", { "exceptions": ["[]"] }
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["[]"] }]*/
foo( [bar, baz] );
foo( [bar, baz], 1);
Examples of incorrect code for this rule with the "always", { "exceptions": ["[]"] }
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["[]"] }]*/
foo( [bar, baz] );
foo( [bar, baz], 1 );
Examples of correct code for this rule with the "always", { "exceptions": ["[]"] }
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["[]"] }]*/
foo([bar, baz]);
foo([bar, baz], 1 );
Examples of incorrect code for this rule with the "never", { "exceptions": ["()"] }]
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["()"] }]*/
foo((1 + 2));
foo((1 + 2), 1);
Examples of correct code for this rule with the "never", { "exceptions": ["()"] }]
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["()"] }]*/
foo( (1 + 2) );
foo( (1 + 2), 1);
Examples of incorrect code for this rule with the "always", { "exceptions": ["()"] }]
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["()"] }]*/
foo( ( 1 + 2 ) );
foo( ( 1 + 2 ), 1 );
Examples of correct code for this rule with the "always", { "exceptions": ["()"] }]
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["()"] }]*/
foo(( 1 + 2 ));
foo(( 1 + 2 ), 1 );
The "empty"
exception concerns empty parentheses, and works the same way as the other exceptions, inverting the first option.
Example of incorrect code for this rule with the "never", { "exceptions": ["empty"] }]
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["empty"] }]*/
foo();
Example of correct code for this rule with the "never", { "exceptions": ["empty"] }]
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["empty"] }]*/
foo( );
Example of incorrect code for this rule with the "always", { "exceptions": ["empty"] }]
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["empty"] }]*/
foo( );
Example of correct code for this rule with the "always", { "exceptions": ["empty"] }]
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["empty"] }]*/
foo();
You can include multiple entries in the "exceptions"
array.
Examples of incorrect code for this rule with the "always", { "exceptions": ["{}", "[]"] }]
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["{}", "[]"] }]*/
bar( {bar:'baz'} );
baz( 1, [1,2] );
foo( {bar: 'baz'}, [1, 2] );
Examples of correct code for this rule with the "always", { "exceptions": ["{}", "[]"] }]
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["{}", "[]"] }]*/
bar({bar:'baz'});
baz( 1, [1,2]);
foo({bar: 'baz'}, [1, 2]);
When Not To Use It
You can turn this rule off if you are not concerned with the consistency of spacing between parentheses.
Related Rules
- [space-in-brackets](space-in-brackets.md) (deprecated) Source: http://eslint.org/docs/rules/
Missing space before function parentheses. Open
tinymce.PluginManager.add('placeholder', function(editor) {
- Read upRead up
- Exclude checks
Require or disallow a space before function parenthesis (space-before-function-paren)
When formatting a function, whitespace is allowed between the function name or function
keyword and the opening paren. Named functions also require a space between the function
keyword and the function name, but anonymous functions require no whitespace. For example:
function withoutSpace(x) {
// ...
}
function withSpace (x) {
// ...
}
var anonymousWithoutSpace = function() {};
var anonymousWithSpace = function () {};
Style guides may require a space after the function
keyword for anonymous functions, while others specify no whitespace. Similarly, the space after a function name may or may not be required.
Rule Details
This rule aims to enforce consistent spacing before function parentheses and as such, will warn whenever whitespace doesn't match the preferences specified.
Options
This rule has a string option or an object option:
{
"space-before-function-paren": ["error", "always"],
// or
"space-before-function-paren": ["error", {
"anonymous": "always",
"named": "always",
"asyncArrow": "ignore"
}],
}
-
always
(default) requires a space followed by the(
of arguments. -
never
disallows any space followed by the(
of arguments.
The string option does not check async arrow function expressions for backward compatibility.
You can also use a separate option for each type of function.
Each of the following options can be set to "always"
, "never"
, or "ignore"
.
Default is "always"
basically.
-
anonymous
is for anonymous function expressions (e.g.function () {}
). -
named
is for named function expressions (e.g.function foo () {}
). -
asyncArrow
is for async arrow function expressions (e.g.async () => {}
).asyncArrow
is set to"ignore"
by default for backwards compatibility.
"always"
Examples of incorrect code for this rule with the default "always"
option:
/*eslint space-before-function-paren: "error"*/
/*eslint-env es6*/
function foo() {
// ...
}
var bar = function() {
// ...
};
var bar = function foo() {
// ...
};
class Foo {
constructor() {
// ...
}
}
var foo = {
bar() {
// ...
}
};
Examples of correct code for this rule with the default "always"
option:
/*eslint space-before-function-paren: "error"*/
/*eslint-env es6*/
function foo () {
// ...
}
var bar = function () {
// ...
};
var bar = function foo () {
// ...
};
class Foo {
constructor () {
// ...
}
}
var foo = {
bar () {
// ...
}
};
// async arrow function expressions are ignored by default.
var foo = async () => 1
var foo = async() => 1
"never"
Examples of incorrect code for this rule with the "never"
option:
/*eslint space-before-function-paren: ["error", "never"]*/
/*eslint-env es6*/
function foo () {
// ...
}
var bar = function () {
// ...
};
var bar = function foo () {
// ...
};
class Foo {
constructor () {
// ...
}
}
var foo = {
bar () {
// ...
}
};
Examples of correct code for this rule with the "never"
option:
/*eslint space-before-function-paren: ["error", "never"]*/
/*eslint-env es6*/
function foo() {
// ...
}
var bar = function() {
// ...
};
var bar = function foo() {
// ...
};
class Foo {
constructor() {
// ...
}
}
var foo = {
bar() {
// ...
}
};
// async arrow function expressions are ignored by default.
var foo = async () => 1
var foo = async() => 1
{"anonymous": "always", "named": "never", "asyncArrow": "always"}
Examples of incorrect code for this rule with the {"anonymous": "always", "named": "never", "asyncArrow": "always"}
option:
/*eslint space-before-function-paren: ["error", {"anonymous": "always", "named": "never", "asyncArrow": "always"}]*/
/*eslint-env es6*/
function foo () {
// ...
}
var bar = function() {
// ...
};
class Foo {
constructor () {
// ...
}
}
var foo = {
bar () {
// ...
}
};
var foo = async(a) => await a
Examples of correct code for this rule with the {"anonymous": "always", "named": "never", "asyncArrow": "always"}
option:
/*eslint space-before-function-paren: ["error", {"anonymous": "always", "named": "never", "asyncArrow": "always"}]*/
/*eslint-env es6*/
function foo() {
// ...
}
var bar = function () {
// ...
};
class Foo {
constructor() {
// ...
}
}
var foo = {
bar() {
// ...
}
};
var foo = async (a) => await a
{"anonymous": "never", "named": "always"}
Examples of incorrect code for this rule with the {"anonymous": "never", "named": "always"}
option:
/*eslint space-before-function-paren: ["error", { "anonymous": "never", "named": "always" }]*/
/*eslint-env es6*/
function foo() {
// ...
}
var bar = function () {
// ...
};
class Foo {
constructor() {
// ...
}
}
var foo = {
bar() {
// ...
}
};
Examples of correct code for this rule with the {"anonymous": "never", "named": "always"}
option:
/*eslint space-before-function-paren: ["error", { "anonymous": "never", "named": "always" }]*/
/*eslint-env es6*/
function foo () {
// ...
}
var bar = function() {
// ...
};
class Foo {
constructor () {
// ...
}
}
var foo = {
bar () {
// ...
}
};
{"anonymous": "ignore", "named": "always"}
Examples of incorrect code for this rule with the {"anonymous": "ignore", "named": "always"}
option:
/*eslint space-before-function-paren: ["error", { "anonymous": "ignore", "named": "always" }]*/
/*eslint-env es6*/
function foo() {
// ...
}
class Foo {
constructor() {
// ...
}
}
var foo = {
bar() {
// ...
}
};
Examples of correct code for this rule with the {"anonymous": "ignore", "named": "always"}
option:
/*eslint space-before-function-paren: ["error", { "anonymous": "ignore", "named": "always" }]*/
/*eslint-env es6*/
var bar = function() {
// ...
};
var bar = function () {
// ...
};
function foo () {
// ...
}
class Foo {
constructor () {
// ...
}
}
var foo = {
bar () {
// ...
}
};
When Not To Use It
You can turn this rule off if you are not concerned with the consistency of spacing before function parenthesis.
Related Rules
- [space-after-keywords](space-after-keywords.md)
- [space-return-throw-case](space-return-throw-case.md) Source: http://eslint.org/docs/rules/
Expected indentation of 6 spaces but found 8. Open
var label = new Label;
- Read upRead up
- Exclude checks
enforce consistent indentation (indent)
There are several common guidelines which require specific indentation of nested blocks and statements, like:
function hello(indentSize, type) {
if (indentSize === 4 && type !== 'tab') {
console.log('Each next indentation will increase on 4 spaces');
}
}
These are the most common scenarios recommended in different style guides:
- Two spaces, not longer and no tabs: Google, npm, Node.js, Idiomatic, Felix
- Tabs: jQuery
- Four spaces: Crockford
Rule Details
This rule enforces a consistent indentation style. The default style is 4 spaces
.
Options
This rule has a mixed option:
For example, for 2-space indentation:
{
"indent": ["error", 2]
}
Or for tabbed indentation:
{
"indent": ["error", "tab"]
}
Examples of incorrect code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
This rule has an object option:
-
"SwitchCase"
(default: 0) enforces indentation level forcase
clauses inswitch
statements -
"VariableDeclarator"
(default: 1) enforces indentation level forvar
declarators; can also take an object to define separate rules forvar
,let
andconst
declarations. -
"outerIIFEBody"
(default: 1) enforces indentation level for file-level IIFEs. -
"MemberExpression"
(off by default) enforces indentation level for multi-line property chains (except in variable declarations and assignments) -
"FunctionDeclaration"
takes an object to define rules for function declarations.-
parameters
(off by default) enforces indentation level for parameters in a function declaration. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the declaration must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function declaration.
-
-
"FunctionExpression"
takes an object to define rules for function expressions.-
parameters
(off by default) enforces indentation level for parameters in a function expression. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the expression must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function expression.
-
-
"CallExpression"
takes an object to define rules for function call expressions.-
arguments
(off by default) enforces indentation level for arguments in a call expression. This can either be a number indicating indentation level, or the string"first"
indicating that all arguments of the expression must be aligned with the first argument.
-
-
"ArrayExpression"
(default: 1) enforces indentation level for elements in arrays. It can also be set to the string"first"
, indicating that all the elements in the array should be aligned with the first element. -
"ObjectExpression"
(default: 1) enforces indentation level for properties in objects. It can be set to the string"first"
, indicating that all properties in the object should be aligned with the first property.
Level of indentation denotes the multiple of the indent specified. Example:
- Indent of 4 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 8 spaces. - Indent of 2 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 4 spaces. - Indent of 2 spaces with
VariableDeclarator
set to{"var": 2, "let": 2, "const": 3}
will indent the multi-line variable declarations with 4 spaces forvar
andlet
, 6 spaces forconst
statements. - Indent of tab with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 2 tabs. - Indent of 2 spaces with
SwitchCase
set to0
will not indentcase
clauses with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to1
will indentcase
clauses with 2 spaces with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to2
will indentcase
clauses with 4 spaces with respect toswitch
statements. - Indent of tab with
SwitchCase
set to2
will indentcase
clauses with 2 tabs with respect toswitch
statements. - Indent of 2 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 2 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 2 spaces. - Indent of 2 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 4 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 8 spaces.
tab
Examples of incorrect code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
/*tab*/b=c;
/*tab*/function foo(d) {
/*tab*//*tab*/e=f;
/*tab*/}
}
SwitchCase
Examples of incorrect code for this rule with the 2, { "SwitchCase": 1 }
options:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
Examples of correct code for this rule with the 2, { "SwitchCase": 1 }
option:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
VariableDeclarator
Examples of incorrect code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 2 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 2 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
outerIIFEBody
Examples of incorrect code for this rule with the options 2, { "outerIIFEBody": 0 }
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
Examples of correct code for this rule with the options 2, {"outerIIFEBody": 0}
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
MemberExpression
Examples of incorrect code for this rule with the 2, { "MemberExpression": 1 }
options:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz()
Examples of correct code for this rule with the 2, { "MemberExpression": 1 }
option:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz();
// Any indentation is permitted in variable declarations and assignments.
var bip = aardvark.badger
.coyote;
FunctionDeclaration
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
FunctionExpression
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
CallExpression
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
ArrayExpression
Examples of incorrect code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of incorrect code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
ObjectExpression
Examples of incorrect code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of correct code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of incorrect code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Examples of correct code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Compatibility
-
JSHint:
indent
- JSCS: validateIndentation Source: http://eslint.org/docs/rules/
Expected indentation of 6 spaces but found 8. Open
editor.on('change', onBlur);
- Read upRead up
- Exclude checks
enforce consistent indentation (indent)
There are several common guidelines which require specific indentation of nested blocks and statements, like:
function hello(indentSize, type) {
if (indentSize === 4 && type !== 'tab') {
console.log('Each next indentation will increase on 4 spaces');
}
}
These are the most common scenarios recommended in different style guides:
- Two spaces, not longer and no tabs: Google, npm, Node.js, Idiomatic, Felix
- Tabs: jQuery
- Four spaces: Crockford
Rule Details
This rule enforces a consistent indentation style. The default style is 4 spaces
.
Options
This rule has a mixed option:
For example, for 2-space indentation:
{
"indent": ["error", 2]
}
Or for tabbed indentation:
{
"indent": ["error", "tab"]
}
Examples of incorrect code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
This rule has an object option:
-
"SwitchCase"
(default: 0) enforces indentation level forcase
clauses inswitch
statements -
"VariableDeclarator"
(default: 1) enforces indentation level forvar
declarators; can also take an object to define separate rules forvar
,let
andconst
declarations. -
"outerIIFEBody"
(default: 1) enforces indentation level for file-level IIFEs. -
"MemberExpression"
(off by default) enforces indentation level for multi-line property chains (except in variable declarations and assignments) -
"FunctionDeclaration"
takes an object to define rules for function declarations.-
parameters
(off by default) enforces indentation level for parameters in a function declaration. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the declaration must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function declaration.
-
-
"FunctionExpression"
takes an object to define rules for function expressions.-
parameters
(off by default) enforces indentation level for parameters in a function expression. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the expression must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function expression.
-
-
"CallExpression"
takes an object to define rules for function call expressions.-
arguments
(off by default) enforces indentation level for arguments in a call expression. This can either be a number indicating indentation level, or the string"first"
indicating that all arguments of the expression must be aligned with the first argument.
-
-
"ArrayExpression"
(default: 1) enforces indentation level for elements in arrays. It can also be set to the string"first"
, indicating that all the elements in the array should be aligned with the first element. -
"ObjectExpression"
(default: 1) enforces indentation level for properties in objects. It can be set to the string"first"
, indicating that all properties in the object should be aligned with the first property.
Level of indentation denotes the multiple of the indent specified. Example:
- Indent of 4 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 8 spaces. - Indent of 2 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 4 spaces. - Indent of 2 spaces with
VariableDeclarator
set to{"var": 2, "let": 2, "const": 3}
will indent the multi-line variable declarations with 4 spaces forvar
andlet
, 6 spaces forconst
statements. - Indent of tab with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 2 tabs. - Indent of 2 spaces with
SwitchCase
set to0
will not indentcase
clauses with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to1
will indentcase
clauses with 2 spaces with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to2
will indentcase
clauses with 4 spaces with respect toswitch
statements. - Indent of tab with
SwitchCase
set to2
will indentcase
clauses with 2 tabs with respect toswitch
statements. - Indent of 2 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 2 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 2 spaces. - Indent of 2 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 4 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 8 spaces.
tab
Examples of incorrect code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
/*tab*/b=c;
/*tab*/function foo(d) {
/*tab*//*tab*/e=f;
/*tab*/}
}
SwitchCase
Examples of incorrect code for this rule with the 2, { "SwitchCase": 1 }
options:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
Examples of correct code for this rule with the 2, { "SwitchCase": 1 }
option:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
VariableDeclarator
Examples of incorrect code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 2 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 2 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
outerIIFEBody
Examples of incorrect code for this rule with the options 2, { "outerIIFEBody": 0 }
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
Examples of correct code for this rule with the options 2, {"outerIIFEBody": 0}
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
MemberExpression
Examples of incorrect code for this rule with the 2, { "MemberExpression": 1 }
options:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz()
Examples of correct code for this rule with the 2, { "MemberExpression": 1 }
option:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz();
// Any indentation is permitted in variable declarations and assignments.
var bip = aardvark.badger
.coyote;
FunctionDeclaration
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
FunctionExpression
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
CallExpression
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
ArrayExpression
Examples of incorrect code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of incorrect code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
ObjectExpression
Examples of incorrect code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of correct code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of incorrect code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Examples of correct code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Compatibility
-
JSHint:
indent
- JSCS: validateIndentation Source: http://eslint.org/docs/rules/
Expected indentation of 6 spaces but found 8. Open
function onFocus() {
- Read upRead up
- Exclude checks
enforce consistent indentation (indent)
There are several common guidelines which require specific indentation of nested blocks and statements, like:
function hello(indentSize, type) {
if (indentSize === 4 && type !== 'tab') {
console.log('Each next indentation will increase on 4 spaces');
}
}
These are the most common scenarios recommended in different style guides:
- Two spaces, not longer and no tabs: Google, npm, Node.js, Idiomatic, Felix
- Tabs: jQuery
- Four spaces: Crockford
Rule Details
This rule enforces a consistent indentation style. The default style is 4 spaces
.
Options
This rule has a mixed option:
For example, for 2-space indentation:
{
"indent": ["error", 2]
}
Or for tabbed indentation:
{
"indent": ["error", "tab"]
}
Examples of incorrect code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
This rule has an object option:
-
"SwitchCase"
(default: 0) enforces indentation level forcase
clauses inswitch
statements -
"VariableDeclarator"
(default: 1) enforces indentation level forvar
declarators; can also take an object to define separate rules forvar
,let
andconst
declarations. -
"outerIIFEBody"
(default: 1) enforces indentation level for file-level IIFEs. -
"MemberExpression"
(off by default) enforces indentation level for multi-line property chains (except in variable declarations and assignments) -
"FunctionDeclaration"
takes an object to define rules for function declarations.-
parameters
(off by default) enforces indentation level for parameters in a function declaration. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the declaration must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function declaration.
-
-
"FunctionExpression"
takes an object to define rules for function expressions.-
parameters
(off by default) enforces indentation level for parameters in a function expression. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the expression must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function expression.
-
-
"CallExpression"
takes an object to define rules for function call expressions.-
arguments
(off by default) enforces indentation level for arguments in a call expression. This can either be a number indicating indentation level, or the string"first"
indicating that all arguments of the expression must be aligned with the first argument.
-
-
"ArrayExpression"
(default: 1) enforces indentation level for elements in arrays. It can also be set to the string"first"
, indicating that all the elements in the array should be aligned with the first element. -
"ObjectExpression"
(default: 1) enforces indentation level for properties in objects. It can be set to the string"first"
, indicating that all properties in the object should be aligned with the first property.
Level of indentation denotes the multiple of the indent specified. Example:
- Indent of 4 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 8 spaces. - Indent of 2 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 4 spaces. - Indent of 2 spaces with
VariableDeclarator
set to{"var": 2, "let": 2, "const": 3}
will indent the multi-line variable declarations with 4 spaces forvar
andlet
, 6 spaces forconst
statements. - Indent of tab with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 2 tabs. - Indent of 2 spaces with
SwitchCase
set to0
will not indentcase
clauses with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to1
will indentcase
clauses with 2 spaces with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to2
will indentcase
clauses with 4 spaces with respect toswitch
statements. - Indent of tab with
SwitchCase
set to2
will indentcase
clauses with 2 tabs with respect toswitch
statements. - Indent of 2 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 2 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 2 spaces. - Indent of 2 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 4 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 8 spaces.
tab
Examples of incorrect code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
/*tab*/b=c;
/*tab*/function foo(d) {
/*tab*//*tab*/e=f;
/*tab*/}
}
SwitchCase
Examples of incorrect code for this rule with the 2, { "SwitchCase": 1 }
options:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
Examples of correct code for this rule with the 2, { "SwitchCase": 1 }
option:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
VariableDeclarator
Examples of incorrect code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 2 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 2 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
outerIIFEBody
Examples of incorrect code for this rule with the options 2, { "outerIIFEBody": 0 }
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
Examples of correct code for this rule with the options 2, {"outerIIFEBody": 0}
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
MemberExpression
Examples of incorrect code for this rule with the 2, { "MemberExpression": 1 }
options:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz()
Examples of correct code for this rule with the 2, { "MemberExpression": 1 }
option:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz();
// Any indentation is permitted in variable declarations and assignments.
var bip = aardvark.badger
.coyote;
FunctionDeclaration
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
FunctionExpression
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
CallExpression
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
ArrayExpression
Examples of incorrect code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of incorrect code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
ObjectExpression
Examples of incorrect code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of correct code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of incorrect code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Examples of correct code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Compatibility
-
JSHint:
indent
- JSCS: validateIndentation Source: http://eslint.org/docs/rules/
Missing space before value for key 'width'. Open
var placeholder_attrs = editor.settings.placeholder_attrs || {style: {position: 'absolute', top:'5px', left:0, color: '#888', padding: '1%', width:'98%', overflow: 'hidden', 'white-space': 'pre-wrap'} };
- Read upRead up
- Exclude checks
enforce consistent spacing between keys and values in object literal properties (key-spacing)
This rule enforces spacing around the colon in object literal properties. It can verify each property individually, or it can ensure horizontal alignment of adjacent properties in an object literal.
Rule Details
This rule enforces consistent spacing between keys and values in object literal properties. In the case of long lines, it is acceptable to add a new line wherever whitespace is allowed.
Options
This rule has an object option:
-
"beforeColon": false
(default) disallows spaces between the key and the colon in object literals. -
"beforeColon": true
requires at least one space between the key and the colon in object literals. -
"afterColon": true
(default) requires at least one space between the colon and the value in object literals. -
"afterColon": false
disallows spaces between the colon and the value in object literals. -
"mode": "strict"
(default) enforces exactly one space before or after colons in object literals. -
"mode": "minimum"
enforces one or more spaces before or after colons in object literals. -
"align": "value"
enforces horizontal alignment of values in object literals. -
"align": "colon"
enforces horizontal alignment of both colons and values in object literals. -
"align"
with an object value allows for fine-grained spacing when values are being aligned in object literals. -
"singleLine"
specifies a spacing style for single-line object literals. -
"multiLine"
specifies a spacing style for multi-line object literals.
Please note that you can either use the top-level options or the grouped options (singleLine
and multiLine
) but not both.
beforeColon
Examples of incorrect code for this rule with the default { "beforeColon": false }
option:
/*eslint key-spacing: ["error", { "beforeColon": false }]*/
var obj = { "foo" : 42 };
Examples of correct code for this rule with the default { "beforeColon": false }
option:
/*eslint key-spacing: ["error", { "beforeColon": false }]*/
var obj = { "foo": 42 };
Examples of incorrect code for this rule with the { "beforeColon": true }
option:
/*eslint key-spacing: ["error", { "beforeColon": true }]*/
var obj = { "foo": 42 };
Examples of correct code for this rule with the { "beforeColon": true }
option:
/*eslint key-spacing: ["error", { "beforeColon": true }]*/
var obj = { "foo" : 42 };
afterColon
Examples of incorrect code for this rule with the default { "afterColon": true }
option:
/*eslint key-spacing: ["error", { "afterColon": true }]*/
var obj = { "foo":42 };
Examples of correct code for this rule with the default { "afterColon": true }
option:
/*eslint key-spacing: ["error", { "afterColon": true }]*/
var obj = { "foo": 42 };
Examples of incorrect code for this rule with the { "afterColon": false }
option:
/*eslint key-spacing: ["error", { "afterColon": false }]*/
var obj = { "foo": 42 };
Examples of correct code for this rule with the { "afterColon": false }
option:
/*eslint key-spacing: ["error", { "afterColon": false }]*/
var obj = { "foo":42 };
mode
Examples of incorrect code for this rule with the default { "mode": "strict" }
option:
/*eslint key-spacing: ["error", { "mode": "strict" }]*/
call({
foobar: 42,
bat: 2 * 2
});
Examples of correct code for this rule with the default { "mode": "strict" }
option:
/*eslint key-spacing: ["error", { "mode": "strict" }]*/
call({
foobar: 42,
bat: 2 * 2
});
Examples of correct code for this rule with the { "mode": "minimum" }
option:
/*eslint key-spacing: ["error", { "mode": "minimum" }]*/
call({
foobar: 42,
bat: 2 * 2
});
align
Examples of incorrect code for this rule with the { "align": "value" }
option:
/*eslint key-spacing: ["error", { "align": "value" }]*/
var obj = {
a: value,
bcde: 42,
fg : foo()
};
Examples of correct code for this rule with the { "align": "value" }
option:
/*eslint key-spacing: ["error", { "align": "value" }]*/
var obj = {
a: value,
bcde: 42,
fg: foo(),
h: function() {
return this.a;
},
ijkl: 'Non-consecutive lines form a new group'
};
var obj = { a: "foo", longPropertyName: "bar" };
Examples of incorrect code for this rule with the { "align": "colon" }
option:
/*eslint key-spacing: ["error", { "align": "colon" }]*/
call({
foobar: 42,
bat: 2 * 2
});
Examples of correct code for this rule with the { "align": "colon" }
option:
/*eslint key-spacing: ["error", { "align": "colon" }]*/
call({
foobar: 42,
bat : 2 * 2
});
align
The align
option can take additional configuration through the beforeColon
, afterColon
, mode
, and on
options.
If align
is defined as an object, but not all of the parameters are provided, undefined parameters will default to the following:
// Defaults
align: {
"beforeColon": false,
"afterColon": true,
"on": "colon",
"mode": "strict"
}
Examples of correct code for this rule with sample { "align": { } }
options:
/*eslint key-spacing: ["error", {
"align": {
"beforeColon": true,
"afterColon": true,
"on": "colon"
}
}]*/
var obj = {
"one" : 1,
"seven" : 7
}
/*eslint key-spacing: ["error", {
"align": {
"beforeColon": false,
"afterColon": false,
"on": "value"
}
}]*/
var obj = {
"one": 1,
"seven":7
}
align and multiLine
The multiLine
and align
options can differ, which allows for fine-tuned control over the key-spacing
of your files. align
will not inherit from multiLine
if align
is configured as an object.
multiLine
is used any time an object literal spans multiple lines. The align
configuration is used when there is a group of properties in the same object. For example:
var myObj = {
key1: 1, // uses multiLine
key2: 2, // uses align (when defined)
key3: 3, // uses align (when defined)
key4: 4 // uses multiLine
}
Examples of incorrect code for this rule with sample { "align": { }, "multiLine": { } }
options:
/*eslint key-spacing: ["error", {
"multiLine": {
"beforeColon": false,
"afterColon":true
},
"align": {
"beforeColon": true,
"afterColon": true,
"on": "colon"
}
}]*/
var obj = {
"myObjectFunction": function() {
// Do something
},
"one" : 1,
"seven" : 7
}
Examples of correct code for this rule with sample { "align": { }, "multiLine": { } }
options:
/*eslint key-spacing: ["error", {
"multiLine": {
"beforeColon": false,
"afterColon": true
},
"align": {
"beforeColon": true,
"afterColon": true,
"on": "colon"
}
}]*/
var obj = {
"myObjectFunction": function() {
// Do something
//
}, // These are two separate groups, so no alignment between `myObjectFuction` and `one`
"one" : 1,
"seven" : 7 // `one` and `seven` are in their own group, and therefore aligned
}
singleLine and multiLine
Examples of correct code for this rule with sample { "singleLine": { }, "multiLine": { } }
options:
/*eslint "key-spacing": [2, {
"singleLine": {
"beforeColon": false,
"afterColon": true
},
"multiLine": {
"beforeColon": true,
"afterColon": true,
"align": "colon"
}
}]*/
var obj = { one: 1, "two": 2, three: 3 };
var obj2 = {
"two" : 2,
three : 3
};
When Not To Use It
If you have another convention for property spacing that might not be consistent with the available options, or if you want to permit multiple styles concurrently you can safely disable this rule. Source: http://eslint.org/docs/rules/
Expected indentation of 6 spaces but found 8. Open
editor.on('keydown', onKeydown);
- Read upRead up
- Exclude checks
enforce consistent indentation (indent)
There are several common guidelines which require specific indentation of nested blocks and statements, like:
function hello(indentSize, type) {
if (indentSize === 4 && type !== 'tab') {
console.log('Each next indentation will increase on 4 spaces');
}
}
These are the most common scenarios recommended in different style guides:
- Two spaces, not longer and no tabs: Google, npm, Node.js, Idiomatic, Felix
- Tabs: jQuery
- Four spaces: Crockford
Rule Details
This rule enforces a consistent indentation style. The default style is 4 spaces
.
Options
This rule has a mixed option:
For example, for 2-space indentation:
{
"indent": ["error", 2]
}
Or for tabbed indentation:
{
"indent": ["error", "tab"]
}
Examples of incorrect code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
This rule has an object option:
-
"SwitchCase"
(default: 0) enforces indentation level forcase
clauses inswitch
statements -
"VariableDeclarator"
(default: 1) enforces indentation level forvar
declarators; can also take an object to define separate rules forvar
,let
andconst
declarations. -
"outerIIFEBody"
(default: 1) enforces indentation level for file-level IIFEs. -
"MemberExpression"
(off by default) enforces indentation level for multi-line property chains (except in variable declarations and assignments) -
"FunctionDeclaration"
takes an object to define rules for function declarations.-
parameters
(off by default) enforces indentation level for parameters in a function declaration. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the declaration must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function declaration.
-
-
"FunctionExpression"
takes an object to define rules for function expressions.-
parameters
(off by default) enforces indentation level for parameters in a function expression. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the expression must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function expression.
-
-
"CallExpression"
takes an object to define rules for function call expressions.-
arguments
(off by default) enforces indentation level for arguments in a call expression. This can either be a number indicating indentation level, or the string"first"
indicating that all arguments of the expression must be aligned with the first argument.
-
-
"ArrayExpression"
(default: 1) enforces indentation level for elements in arrays. It can also be set to the string"first"
, indicating that all the elements in the array should be aligned with the first element. -
"ObjectExpression"
(default: 1) enforces indentation level for properties in objects. It can be set to the string"first"
, indicating that all properties in the object should be aligned with the first property.
Level of indentation denotes the multiple of the indent specified. Example:
- Indent of 4 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 8 spaces. - Indent of 2 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 4 spaces. - Indent of 2 spaces with
VariableDeclarator
set to{"var": 2, "let": 2, "const": 3}
will indent the multi-line variable declarations with 4 spaces forvar
andlet
, 6 spaces forconst
statements. - Indent of tab with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 2 tabs. - Indent of 2 spaces with
SwitchCase
set to0
will not indentcase
clauses with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to1
will indentcase
clauses with 2 spaces with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to2
will indentcase
clauses with 4 spaces with respect toswitch
statements. - Indent of tab with
SwitchCase
set to2
will indentcase
clauses with 2 tabs with respect toswitch
statements. - Indent of 2 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 2 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 2 spaces. - Indent of 2 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 4 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 8 spaces.
tab
Examples of incorrect code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
/*tab*/b=c;
/*tab*/function foo(d) {
/*tab*//*tab*/e=f;
/*tab*/}
}
SwitchCase
Examples of incorrect code for this rule with the 2, { "SwitchCase": 1 }
options:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
Examples of correct code for this rule with the 2, { "SwitchCase": 1 }
option:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
VariableDeclarator
Examples of incorrect code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 2 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 2 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
outerIIFEBody
Examples of incorrect code for this rule with the options 2, { "outerIIFEBody": 0 }
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
Examples of correct code for this rule with the options 2, {"outerIIFEBody": 0}
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
MemberExpression
Examples of incorrect code for this rule with the 2, { "MemberExpression": 1 }
options:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz()
Examples of correct code for this rule with the 2, { "MemberExpression": 1 }
option:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz();
// Any indentation is permitted in variable declarations and assignments.
var bip = aardvark.badger
.coyote;
FunctionDeclaration
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
FunctionExpression
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
CallExpression
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
ArrayExpression
Examples of incorrect code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of incorrect code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
ObjectExpression
Examples of incorrect code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of correct code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of incorrect code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Examples of correct code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Compatibility
-
JSHint:
indent
- JSCS: validateIndentation Source: http://eslint.org/docs/rules/
Expected indentation of 10 spaces but found 12. Open
if (!editor.settings.readonly === true) {
- Read upRead up
- Exclude checks
enforce consistent indentation (indent)
There are several common guidelines which require specific indentation of nested blocks and statements, like:
function hello(indentSize, type) {
if (indentSize === 4 && type !== 'tab') {
console.log('Each next indentation will increase on 4 spaces');
}
}
These are the most common scenarios recommended in different style guides:
- Two spaces, not longer and no tabs: Google, npm, Node.js, Idiomatic, Felix
- Tabs: jQuery
- Four spaces: Crockford
Rule Details
This rule enforces a consistent indentation style. The default style is 4 spaces
.
Options
This rule has a mixed option:
For example, for 2-space indentation:
{
"indent": ["error", 2]
}
Or for tabbed indentation:
{
"indent": ["error", "tab"]
}
Examples of incorrect code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
This rule has an object option:
-
"SwitchCase"
(default: 0) enforces indentation level forcase
clauses inswitch
statements -
"VariableDeclarator"
(default: 1) enforces indentation level forvar
declarators; can also take an object to define separate rules forvar
,let
andconst
declarations. -
"outerIIFEBody"
(default: 1) enforces indentation level for file-level IIFEs. -
"MemberExpression"
(off by default) enforces indentation level for multi-line property chains (except in variable declarations and assignments) -
"FunctionDeclaration"
takes an object to define rules for function declarations.-
parameters
(off by default) enforces indentation level for parameters in a function declaration. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the declaration must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function declaration.
-
-
"FunctionExpression"
takes an object to define rules for function expressions.-
parameters
(off by default) enforces indentation level for parameters in a function expression. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the expression must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function expression.
-
-
"CallExpression"
takes an object to define rules for function call expressions.-
arguments
(off by default) enforces indentation level for arguments in a call expression. This can either be a number indicating indentation level, or the string"first"
indicating that all arguments of the expression must be aligned with the first argument.
-
-
"ArrayExpression"
(default: 1) enforces indentation level for elements in arrays. It can also be set to the string"first"
, indicating that all the elements in the array should be aligned with the first element. -
"ObjectExpression"
(default: 1) enforces indentation level for properties in objects. It can be set to the string"first"
, indicating that all properties in the object should be aligned with the first property.
Level of indentation denotes the multiple of the indent specified. Example:
- Indent of 4 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 8 spaces. - Indent of 2 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 4 spaces. - Indent of 2 spaces with
VariableDeclarator
set to{"var": 2, "let": 2, "const": 3}
will indent the multi-line variable declarations with 4 spaces forvar
andlet
, 6 spaces forconst
statements. - Indent of tab with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 2 tabs. - Indent of 2 spaces with
SwitchCase
set to0
will not indentcase
clauses with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to1
will indentcase
clauses with 2 spaces with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to2
will indentcase
clauses with 4 spaces with respect toswitch
statements. - Indent of tab with
SwitchCase
set to2
will indentcase
clauses with 2 tabs with respect toswitch
statements. - Indent of 2 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 2 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 2 spaces. - Indent of 2 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 4 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 8 spaces.
tab
Examples of incorrect code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
/*tab*/b=c;
/*tab*/function foo(d) {
/*tab*//*tab*/e=f;
/*tab*/}
}
SwitchCase
Examples of incorrect code for this rule with the 2, { "SwitchCase": 1 }
options:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
Examples of correct code for this rule with the 2, { "SwitchCase": 1 }
option:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
VariableDeclarator
Examples of incorrect code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 2 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 2 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
outerIIFEBody
Examples of incorrect code for this rule with the options 2, { "outerIIFEBody": 0 }
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
Examples of correct code for this rule with the options 2, {"outerIIFEBody": 0}
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
MemberExpression
Examples of incorrect code for this rule with the 2, { "MemberExpression": 1 }
options:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz()
Examples of correct code for this rule with the 2, { "MemberExpression": 1 }
option:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz();
// Any indentation is permitted in variable declarations and assignments.
var bip = aardvark.badger
.coyote;
FunctionDeclaration
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
FunctionExpression
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
CallExpression
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
ArrayExpression
Examples of incorrect code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of incorrect code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
ObjectExpression
Examples of incorrect code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of correct code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of incorrect code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Examples of correct code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Compatibility
-
JSHint:
indent
- JSCS: validateIndentation Source: http://eslint.org/docs/rules/
Expected indentation of 14 spaces but found 16. Open
label.hide();
- Read upRead up
- Exclude checks
enforce consistent indentation (indent)
There are several common guidelines which require specific indentation of nested blocks and statements, like:
function hello(indentSize, type) {
if (indentSize === 4 && type !== 'tab') {
console.log('Each next indentation will increase on 4 spaces');
}
}
These are the most common scenarios recommended in different style guides:
- Two spaces, not longer and no tabs: Google, npm, Node.js, Idiomatic, Felix
- Tabs: jQuery
- Four spaces: Crockford
Rule Details
This rule enforces a consistent indentation style. The default style is 4 spaces
.
Options
This rule has a mixed option:
For example, for 2-space indentation:
{
"indent": ["error", 2]
}
Or for tabbed indentation:
{
"indent": ["error", "tab"]
}
Examples of incorrect code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
This rule has an object option:
-
"SwitchCase"
(default: 0) enforces indentation level forcase
clauses inswitch
statements -
"VariableDeclarator"
(default: 1) enforces indentation level forvar
declarators; can also take an object to define separate rules forvar
,let
andconst
declarations. -
"outerIIFEBody"
(default: 1) enforces indentation level for file-level IIFEs. -
"MemberExpression"
(off by default) enforces indentation level for multi-line property chains (except in variable declarations and assignments) -
"FunctionDeclaration"
takes an object to define rules for function declarations.-
parameters
(off by default) enforces indentation level for parameters in a function declaration. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the declaration must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function declaration.
-
-
"FunctionExpression"
takes an object to define rules for function expressions.-
parameters
(off by default) enforces indentation level for parameters in a function expression. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the expression must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function expression.
-
-
"CallExpression"
takes an object to define rules for function call expressions.-
arguments
(off by default) enforces indentation level for arguments in a call expression. This can either be a number indicating indentation level, or the string"first"
indicating that all arguments of the expression must be aligned with the first argument.
-
-
"ArrayExpression"
(default: 1) enforces indentation level for elements in arrays. It can also be set to the string"first"
, indicating that all the elements in the array should be aligned with the first element. -
"ObjectExpression"
(default: 1) enforces indentation level for properties in objects. It can be set to the string"first"
, indicating that all properties in the object should be aligned with the first property.
Level of indentation denotes the multiple of the indent specified. Example:
- Indent of 4 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 8 spaces. - Indent of 2 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 4 spaces. - Indent of 2 spaces with
VariableDeclarator
set to{"var": 2, "let": 2, "const": 3}
will indent the multi-line variable declarations with 4 spaces forvar
andlet
, 6 spaces forconst
statements. - Indent of tab with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 2 tabs. - Indent of 2 spaces with
SwitchCase
set to0
will not indentcase
clauses with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to1
will indentcase
clauses with 2 spaces with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to2
will indentcase
clauses with 4 spaces with respect toswitch
statements. - Indent of tab with
SwitchCase
set to2
will indentcase
clauses with 2 tabs with respect toswitch
statements. - Indent of 2 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 2 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 2 spaces. - Indent of 2 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 4 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 8 spaces.
tab
Examples of incorrect code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
/*tab*/b=c;
/*tab*/function foo(d) {
/*tab*//*tab*/e=f;
/*tab*/}
}
SwitchCase
Examples of incorrect code for this rule with the 2, { "SwitchCase": 1 }
options:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
Examples of correct code for this rule with the 2, { "SwitchCase": 1 }
option:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
VariableDeclarator
Examples of incorrect code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 2 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 2 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
outerIIFEBody
Examples of incorrect code for this rule with the options 2, { "outerIIFEBody": 0 }
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
Examples of correct code for this rule with the options 2, {"outerIIFEBody": 0}
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
MemberExpression
Examples of incorrect code for this rule with the 2, { "MemberExpression": 1 }
options:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz()
Examples of correct code for this rule with the 2, { "MemberExpression": 1 }
option:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz();
// Any indentation is permitted in variable declarations and assignments.
var bip = aardvark.badger
.coyote;
FunctionDeclaration
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
FunctionExpression
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
CallExpression
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
ArrayExpression
Examples of incorrect code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of incorrect code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
ObjectExpression
Examples of incorrect code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of correct code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of incorrect code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Examples of correct code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Compatibility
-
JSHint:
indent
- JSCS: validateIndentation Source: http://eslint.org/docs/rules/
Unexpected var, use let or const instead. Open
var Label = function(){
- Read upRead up
- Exclude checks
require let
or const
instead of var
(no-var)
ECMAScript 6 allows programmers to create variables with block scope instead of function scope using the let
and const
keywords. Block scope is common in many other programming languages and helps programmers avoid mistakes
such as:
var count = people.length;
var enoughFood = count > sandwiches.length;
if (enoughFood) {
var count = sandwiches.length; // accidentally overriding the count variable
console.log("We have " + count + " sandwiches for everyone. Plenty for all!");
}
// our count variable is no longer accurate
console.log("We have " + count + " people and " + sandwiches.length + " sandwiches!");
Rule Details
This rule is aimed at discouraging the use of var
and encouraging the use of const
or let
instead.
Examples
Examples of incorrect code for this rule:
/*eslint no-var: "error"*/
var x = "y";
var CONFIG = {};
Examples of correct code for this rule:
/*eslint no-var: "error"*/
/*eslint-env es6*/
let x = "y";
const CONFIG = {};
When Not To Use It
In addition to non-ES6 environments, existing JavaScript projects that are beginning to introduce ES6 into their
codebase may not want to apply this rule if the cost of migrating from var
to let
is too costly.
Source: http://eslint.org/docs/rules/
Unexpected var, use let or const instead. Open
var placeholder_attrs = editor.settings.placeholder_attrs || {style: {position: 'absolute', top:'5px', left:0, color: '#888', padding: '1%', width:'98%', overflow: 'hidden', 'white-space': 'pre-wrap'} };
- Read upRead up
- Exclude checks
require let
or const
instead of var
(no-var)
ECMAScript 6 allows programmers to create variables with block scope instead of function scope using the let
and const
keywords. Block scope is common in many other programming languages and helps programmers avoid mistakes
such as:
var count = people.length;
var enoughFood = count > sandwiches.length;
if (enoughFood) {
var count = sandwiches.length; // accidentally overriding the count variable
console.log("We have " + count + " sandwiches for everyone. Plenty for all!");
}
// our count variable is no longer accurate
console.log("We have " + count + " people and " + sandwiches.length + " sandwiches!");
Rule Details
This rule is aimed at discouraging the use of var
and encouraging the use of const
or let
instead.
Examples
Examples of incorrect code for this rule:
/*eslint no-var: "error"*/
var x = "y";
var CONFIG = {};
Examples of correct code for this rule:
/*eslint no-var: "error"*/
/*eslint-env es6*/
let x = "y";
const CONFIG = {};
When Not To Use It
In addition to non-ES6 environments, existing JavaScript projects that are beginning to introduce ES6 into their
codebase may not want to apply this rule if the cost of migrating from var
to let
is too costly.
Source: http://eslint.org/docs/rules/
Expected indentation of 6 spaces but found 8. Open
tinymce.DOM.bind(label.el, 'click', onFocus);
- Read upRead up
- Exclude checks
enforce consistent indentation (indent)
There are several common guidelines which require specific indentation of nested blocks and statements, like:
function hello(indentSize, type) {
if (indentSize === 4 && type !== 'tab') {
console.log('Each next indentation will increase on 4 spaces');
}
}
These are the most common scenarios recommended in different style guides:
- Two spaces, not longer and no tabs: Google, npm, Node.js, Idiomatic, Felix
- Tabs: jQuery
- Four spaces: Crockford
Rule Details
This rule enforces a consistent indentation style. The default style is 4 spaces
.
Options
This rule has a mixed option:
For example, for 2-space indentation:
{
"indent": ["error", 2]
}
Or for tabbed indentation:
{
"indent": ["error", "tab"]
}
Examples of incorrect code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
This rule has an object option:
-
"SwitchCase"
(default: 0) enforces indentation level forcase
clauses inswitch
statements -
"VariableDeclarator"
(default: 1) enforces indentation level forvar
declarators; can also take an object to define separate rules forvar
,let
andconst
declarations. -
"outerIIFEBody"
(default: 1) enforces indentation level for file-level IIFEs. -
"MemberExpression"
(off by default) enforces indentation level for multi-line property chains (except in variable declarations and assignments) -
"FunctionDeclaration"
takes an object to define rules for function declarations.-
parameters
(off by default) enforces indentation level for parameters in a function declaration. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the declaration must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function declaration.
-
-
"FunctionExpression"
takes an object to define rules for function expressions.-
parameters
(off by default) enforces indentation level for parameters in a function expression. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the expression must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function expression.
-
-
"CallExpression"
takes an object to define rules for function call expressions.-
arguments
(off by default) enforces indentation level for arguments in a call expression. This can either be a number indicating indentation level, or the string"first"
indicating that all arguments of the expression must be aligned with the first argument.
-
-
"ArrayExpression"
(default: 1) enforces indentation level for elements in arrays. It can also be set to the string"first"
, indicating that all the elements in the array should be aligned with the first element. -
"ObjectExpression"
(default: 1) enforces indentation level for properties in objects. It can be set to the string"first"
, indicating that all properties in the object should be aligned with the first property.
Level of indentation denotes the multiple of the indent specified. Example:
- Indent of 4 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 8 spaces. - Indent of 2 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 4 spaces. - Indent of 2 spaces with
VariableDeclarator
set to{"var": 2, "let": 2, "const": 3}
will indent the multi-line variable declarations with 4 spaces forvar
andlet
, 6 spaces forconst
statements. - Indent of tab with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 2 tabs. - Indent of 2 spaces with
SwitchCase
set to0
will not indentcase
clauses with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to1
will indentcase
clauses with 2 spaces with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to2
will indentcase
clauses with 4 spaces with respect toswitch
statements. - Indent of tab with
SwitchCase
set to2
will indentcase
clauses with 2 tabs with respect toswitch
statements. - Indent of 2 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 2 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 2 spaces. - Indent of 2 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 4 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 8 spaces.
tab
Examples of incorrect code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
/*tab*/b=c;
/*tab*/function foo(d) {
/*tab*//*tab*/e=f;
/*tab*/}
}
SwitchCase
Examples of incorrect code for this rule with the 2, { "SwitchCase": 1 }
options:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
Examples of correct code for this rule with the 2, { "SwitchCase": 1 }
option:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
VariableDeclarator
Examples of incorrect code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 2 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 2 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
outerIIFEBody
Examples of incorrect code for this rule with the options 2, { "outerIIFEBody": 0 }
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
Examples of correct code for this rule with the options 2, {"outerIIFEBody": 0}
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
MemberExpression
Examples of incorrect code for this rule with the 2, { "MemberExpression": 1 }
options:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz()
Examples of correct code for this rule with the 2, { "MemberExpression": 1 }
option:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz();
// Any indentation is permitted in variable declarations and assignments.
var bip = aardvark.badger
.coyote;
FunctionDeclaration
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
FunctionExpression
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
CallExpression
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
ArrayExpression
Examples of incorrect code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of incorrect code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
ObjectExpression
Examples of incorrect code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of correct code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of incorrect code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Examples of correct code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Compatibility
-
JSHint:
indent
- JSCS: validateIndentation Source: http://eslint.org/docs/rules/
Unexpected function expression. Open
editor.on('init', function() {
- Read upRead up
- Exclude checks
Suggest using arrow functions as callbacks. (prefer-arrow-callback)
Arrow functions are suited to callbacks, because:
-
this
keywords in arrow functions bind to the upper scope's. - The notation of the arrow function is shorter than function expression's.
Rule Details
This rule is aimed to flag usage of function expressions in an argument list.
The following patterns are considered problems:
/*eslint prefer-arrow-callback: "error"*/
foo(function(a) { return a; });
foo(function() { return this.a; }.bind(this));
The following patterns are not considered problems:
/*eslint prefer-arrow-callback: "error"*/
/*eslint-env es6*/
foo(a => a);
foo(function*() { yield; });
// this is not a callback.
var foo = function foo(a) { return a; };
// using `this` without `.bind(this)`.
foo(function() { return this.a; });
// recursively.
foo(function bar(n) { return n && n + bar(n - 1); });
Options
This rule takes one optional argument, an object which is an options object.
allowNamedFunctions
This is a boolean
option and it is false
by default. When set to true
, the rule doesn't warn on named functions used as callbacks.
Examples of correct code for the { "allowNamedFunctions": true }
option:
/*eslint prefer-arrow-callback: ["error", { "allowNamedFunctions": true }]*/
foo(function bar() {});
allowUnboundThis
This is a boolean
option and it is true
by default. When set to false
, this option allows the use of this
without restriction and checks for dynamically assigned this
values such as when using Array.prototype.map
with a context
argument. Normally, the rule will flag the use of this
whenever a function does not use bind()
to specify the value of this
constantly.
Examples of incorrect code for the { "allowUnboundThis": false }
option:
/*eslint prefer-arrow-callback: ["error", { "allowUnboundThis": false }]*/
/*eslint-env es6*/
foo(function() { this.a; });
foo(function() { (() => this); });
someArray.map(function (itm) { return this.doSomething(itm); }, someObject);
When Not To Use It
This rule should not be used in ES3/5 environments.
In ES2015 (ES6) or later, if you don't want to be notified about function expressions in an argument list, you can safely disable this rule. Source: http://eslint.org/docs/rules/
Unexpected var, use let or const instead. Open
var placeholder_text = editor.getElement().getAttribute("placeholder") || editor.settings.placeholder;
- Read upRead up
- Exclude checks
require let
or const
instead of var
(no-var)
ECMAScript 6 allows programmers to create variables with block scope instead of function scope using the let
and const
keywords. Block scope is common in many other programming languages and helps programmers avoid mistakes
such as:
var count = people.length;
var enoughFood = count > sandwiches.length;
if (enoughFood) {
var count = sandwiches.length; // accidentally overriding the count variable
console.log("We have " + count + " sandwiches for everyone. Plenty for all!");
}
// our count variable is no longer accurate
console.log("We have " + count + " people and " + sandwiches.length + " sandwiches!");
Rule Details
This rule is aimed at discouraging the use of var
and encouraging the use of const
or let
instead.
Examples
Examples of incorrect code for this rule:
/*eslint no-var: "error"*/
var x = "y";
var CONFIG = {};
Examples of correct code for this rule:
/*eslint no-var: "error"*/
/*eslint-env es6*/
let x = "y";
const CONFIG = {};
When Not To Use It
In addition to non-ES6 environments, existing JavaScript projects that are beginning to introduce ES6 into their
codebase may not want to apply this rule if the cost of migrating from var
to let
is too costly.
Source: http://eslint.org/docs/rules/
Identifier 'placeholder_text' is not in camel case. Open
var placeholder_text = editor.getElement().getAttribute("placeholder") || editor.settings.placeholder;
- Read upRead up
- Exclude checks
Require Camelcase (camelcase)
When it comes to naming variables, style guides generally fall into one of two camps: camelcase (variableName
) and underscores (variable_name
). This rule focuses on using the camelcase approach. If your style guide calls for camelcasing your variable names, then this rule is for you!
Rule Details
This rule looks for any underscores (_
) located within the source code. It ignores leading and trailing underscores and only checks those in the middle of a variable name. If ESLint decides that the variable is a constant (all uppercase), then no warning will be thrown. Otherwise, a warning will be thrown. This rule only flags definitions and assignments but not function calls. In case of ES6 import
statements, this rule only targets the name of the variable that will be imported into the local module scope.
Options
This rule has an object option:
-
"properties": "always"
(default) enforces camelcase style for property names -
"properties": "never"
does not check property names
always
Examples of incorrect code for this rule with the default { "properties": "always" }
option:
/*eslint camelcase: "error"*/
import { no_camelcased } from "external-module"
var my_favorite_color = "#112C85";
function do_something() {
// ...
}
obj.do_something = function() {
// ...
};
var obj = {
my_pref: 1
};
Examples of correct code for this rule with the default { "properties": "always" }
option:
/*eslint camelcase: "error"*/
import { no_camelcased as camelCased } from "external-module";
var myFavoriteColor = "#112C85";
var _myFavoriteColor = "#112C85";
var myFavoriteColor_ = "#112C85";
var MY_FAVORITE_COLOR = "#112C85";
var foo = bar.baz_boom;
var foo = { qux: bar.baz_boom };
obj.do_something();
do_something();
new do_something();
var { category_id: category } = query;
never
Examples of correct code for this rule with the { "properties": "never" }
option:
/*eslint camelcase: ["error", {properties: "never"}]*/
var obj = {
my_pref: 1
};
When Not To Use It
If you have established coding standards using a different naming convention (separating words with underscores), turn this rule off. Source: http://eslint.org/docs/rules/
Expected indentation of 14 spaces but found 16. Open
label.show();
- Read upRead up
- Exclude checks
enforce consistent indentation (indent)
There are several common guidelines which require specific indentation of nested blocks and statements, like:
function hello(indentSize, type) {
if (indentSize === 4 && type !== 'tab') {
console.log('Each next indentation will increase on 4 spaces');
}
}
These are the most common scenarios recommended in different style guides:
- Two spaces, not longer and no tabs: Google, npm, Node.js, Idiomatic, Felix
- Tabs: jQuery
- Four spaces: Crockford
Rule Details
This rule enforces a consistent indentation style. The default style is 4 spaces
.
Options
This rule has a mixed option:
For example, for 2-space indentation:
{
"indent": ["error", 2]
}
Or for tabbed indentation:
{
"indent": ["error", "tab"]
}
Examples of incorrect code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
This rule has an object option:
-
"SwitchCase"
(default: 0) enforces indentation level forcase
clauses inswitch
statements -
"VariableDeclarator"
(default: 1) enforces indentation level forvar
declarators; can also take an object to define separate rules forvar
,let
andconst
declarations. -
"outerIIFEBody"
(default: 1) enforces indentation level for file-level IIFEs. -
"MemberExpression"
(off by default) enforces indentation level for multi-line property chains (except in variable declarations and assignments) -
"FunctionDeclaration"
takes an object to define rules for function declarations.-
parameters
(off by default) enforces indentation level for parameters in a function declaration. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the declaration must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function declaration.
-
-
"FunctionExpression"
takes an object to define rules for function expressions.-
parameters
(off by default) enforces indentation level for parameters in a function expression. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the expression must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function expression.
-
-
"CallExpression"
takes an object to define rules for function call expressions.-
arguments
(off by default) enforces indentation level for arguments in a call expression. This can either be a number indicating indentation level, or the string"first"
indicating that all arguments of the expression must be aligned with the first argument.
-
-
"ArrayExpression"
(default: 1) enforces indentation level for elements in arrays. It can also be set to the string"first"
, indicating that all the elements in the array should be aligned with the first element. -
"ObjectExpression"
(default: 1) enforces indentation level for properties in objects. It can be set to the string"first"
, indicating that all properties in the object should be aligned with the first property.
Level of indentation denotes the multiple of the indent specified. Example:
- Indent of 4 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 8 spaces. - Indent of 2 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 4 spaces. - Indent of 2 spaces with
VariableDeclarator
set to{"var": 2, "let": 2, "const": 3}
will indent the multi-line variable declarations with 4 spaces forvar
andlet
, 6 spaces forconst
statements. - Indent of tab with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 2 tabs. - Indent of 2 spaces with
SwitchCase
set to0
will not indentcase
clauses with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to1
will indentcase
clauses with 2 spaces with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to2
will indentcase
clauses with 4 spaces with respect toswitch
statements. - Indent of tab with
SwitchCase
set to2
will indentcase
clauses with 2 tabs with respect toswitch
statements. - Indent of 2 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 2 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 2 spaces. - Indent of 2 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 4 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 8 spaces.
tab
Examples of incorrect code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
/*tab*/b=c;
/*tab*/function foo(d) {
/*tab*//*tab*/e=f;
/*tab*/}
}
SwitchCase
Examples of incorrect code for this rule with the 2, { "SwitchCase": 1 }
options:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
Examples of correct code for this rule with the 2, { "SwitchCase": 1 }
option:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
VariableDeclarator
Examples of incorrect code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 2 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 2 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
outerIIFEBody
Examples of incorrect code for this rule with the options 2, { "outerIIFEBody": 0 }
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
Examples of correct code for this rule with the options 2, {"outerIIFEBody": 0}
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
MemberExpression
Examples of incorrect code for this rule with the 2, { "MemberExpression": 1 }
options:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz()
Examples of correct code for this rule with the 2, { "MemberExpression": 1 }
option:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz();
// Any indentation is permitted in variable declarations and assignments.
var bip = aardvark.badger
.coyote;
FunctionDeclaration
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
FunctionExpression
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
CallExpression
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
ArrayExpression
Examples of incorrect code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of incorrect code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
ObjectExpression
Examples of incorrect code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of correct code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of incorrect code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Examples of correct code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Compatibility
-
JSHint:
indent
- JSCS: validateIndentation Source: http://eslint.org/docs/rules/
There should be no spaces inside this paren. Open
this.el = tinymce.DOM.add( contentAreaContainer, editor.settings.placeholder_tag || "label", placeholder_attrs, placeholder_text );
- Read upRead up
- Exclude checks
Disallow or enforce spaces inside of parentheses (space-in-parens)
Some style guides require or disallow spaces inside of parentheses:
foo( 'bar' );
var x = ( 1 + 2 ) * 3;
foo('bar');
var x = (1 + 2) * 3;
Rule Details
This rule will enforce consistency of spacing directly inside of parentheses, by disallowing or requiring one or more spaces to the right of (
and to the left of )
. In either case, ()
will still be allowed.
Options
There are two options for this rule:
-
"never"
(default) enforces zero spaces inside of parentheses -
"always"
enforces a space inside of parentheses
Depending on your coding conventions, you can choose either option by specifying it in your configuration:
"space-in-parens": ["error", "always"]
"never"
Examples of incorrect code for this rule with the default "never"
option:
/*eslint space-in-parens: ["error", "never"]*/
foo( 'bar');
foo('bar' );
foo( 'bar' );
var foo = ( 1 + 2 ) * 3;
( function () { return 'bar'; }() );
Examples of correct code for this rule with the default "never"
option:
/*eslint space-in-parens: ["error", "never"]*/
foo();
foo('bar');
var foo = (1 + 2) * 3;
(function () { return 'bar'; }());
"always"
Examples of incorrect code for this rule with the "always"
option:
/*eslint space-in-parens: ["error", "always"]*/
foo( 'bar');
foo('bar' );
foo('bar');
var foo = (1 + 2) * 3;
(function () { return 'bar'; }());
Examples of correct code for this rule with the "always"
option:
/*eslint space-in-parens: ["error", "always"]*/
foo();
foo( 'bar' );
var foo = ( 1 + 2 ) * 3;
( function () { return 'bar'; }() );
Exceptions
An object literal may be used as a third array item to specify exceptions, with the key "exceptions"
and an array as the value. These exceptions work in the context of the first option. That is, if "always"
is set to enforce spacing, then any "exception" will disallow spacing. Conversely, if "never"
is set to disallow spacing, then any "exception" will enforce spacing.
The following exceptions are available: ["{}", "[]", "()", "empty"]
.
Examples of incorrect code for this rule with the "never", { "exceptions": ["{}"] }
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["{}"] }]*/
foo({bar: 'baz'});
foo(1, {bar: 'baz'});
Examples of correct code for this rule with the "never", { "exceptions": ["{}"] }
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["{}"] }]*/
foo( {bar: 'baz'} );
foo(1, {bar: 'baz'} );
Examples of incorrect code for this rule with the "always", { "exceptions": ["{}"] }
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["{}"] }]*/
foo( {bar: 'baz'} );
foo( 1, {bar: 'baz'} );
Examples of correct code for this rule with the "always", { "exceptions": ["{}"] }
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["{}"] }]*/
foo({bar: 'baz'});
foo( 1, {bar: 'baz'});
Examples of incorrect code for this rule with the "never", { "exceptions": ["[]"] }
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["[]"] }]*/
foo([bar, baz]);
foo([bar, baz], 1);
Examples of correct code for this rule with the "never", { "exceptions": ["[]"] }
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["[]"] }]*/
foo( [bar, baz] );
foo( [bar, baz], 1);
Examples of incorrect code for this rule with the "always", { "exceptions": ["[]"] }
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["[]"] }]*/
foo( [bar, baz] );
foo( [bar, baz], 1 );
Examples of correct code for this rule with the "always", { "exceptions": ["[]"] }
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["[]"] }]*/
foo([bar, baz]);
foo([bar, baz], 1 );
Examples of incorrect code for this rule with the "never", { "exceptions": ["()"] }]
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["()"] }]*/
foo((1 + 2));
foo((1 + 2), 1);
Examples of correct code for this rule with the "never", { "exceptions": ["()"] }]
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["()"] }]*/
foo( (1 + 2) );
foo( (1 + 2), 1);
Examples of incorrect code for this rule with the "always", { "exceptions": ["()"] }]
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["()"] }]*/
foo( ( 1 + 2 ) );
foo( ( 1 + 2 ), 1 );
Examples of correct code for this rule with the "always", { "exceptions": ["()"] }]
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["()"] }]*/
foo(( 1 + 2 ));
foo(( 1 + 2 ), 1 );
The "empty"
exception concerns empty parentheses, and works the same way as the other exceptions, inverting the first option.
Example of incorrect code for this rule with the "never", { "exceptions": ["empty"] }]
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["empty"] }]*/
foo();
Example of correct code for this rule with the "never", { "exceptions": ["empty"] }]
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["empty"] }]*/
foo( );
Example of incorrect code for this rule with the "always", { "exceptions": ["empty"] }]
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["empty"] }]*/
foo( );
Example of correct code for this rule with the "always", { "exceptions": ["empty"] }]
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["empty"] }]*/
foo();
You can include multiple entries in the "exceptions"
array.
Examples of incorrect code for this rule with the "always", { "exceptions": ["{}", "[]"] }]
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["{}", "[]"] }]*/
bar( {bar:'baz'} );
baz( 1, [1,2] );
foo( {bar: 'baz'}, [1, 2] );
Examples of correct code for this rule with the "always", { "exceptions": ["{}", "[]"] }]
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["{}", "[]"] }]*/
bar({bar:'baz'});
baz( 1, [1,2]);
foo({bar: 'baz'}, [1, 2]);
When Not To Use It
You can turn this rule off if you are not concerned with the consistency of spacing between parentheses.
Related Rules
- [space-in-brackets](space-in-brackets.md) (deprecated) Source: http://eslint.org/docs/rules/
Expected indentation of 2 spaces but found 4. Open
var Label = function(){
- Read upRead up
- Exclude checks
enforce consistent indentation (indent)
There are several common guidelines which require specific indentation of nested blocks and statements, like:
function hello(indentSize, type) {
if (indentSize === 4 && type !== 'tab') {
console.log('Each next indentation will increase on 4 spaces');
}
}
These are the most common scenarios recommended in different style guides:
- Two spaces, not longer and no tabs: Google, npm, Node.js, Idiomatic, Felix
- Tabs: jQuery
- Four spaces: Crockford
Rule Details
This rule enforces a consistent indentation style. The default style is 4 spaces
.
Options
This rule has a mixed option:
For example, for 2-space indentation:
{
"indent": ["error", 2]
}
Or for tabbed indentation:
{
"indent": ["error", "tab"]
}
Examples of incorrect code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
This rule has an object option:
-
"SwitchCase"
(default: 0) enforces indentation level forcase
clauses inswitch
statements -
"VariableDeclarator"
(default: 1) enforces indentation level forvar
declarators; can also take an object to define separate rules forvar
,let
andconst
declarations. -
"outerIIFEBody"
(default: 1) enforces indentation level for file-level IIFEs. -
"MemberExpression"
(off by default) enforces indentation level for multi-line property chains (except in variable declarations and assignments) -
"FunctionDeclaration"
takes an object to define rules for function declarations.-
parameters
(off by default) enforces indentation level for parameters in a function declaration. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the declaration must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function declaration.
-
-
"FunctionExpression"
takes an object to define rules for function expressions.-
parameters
(off by default) enforces indentation level for parameters in a function expression. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the expression must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function expression.
-
-
"CallExpression"
takes an object to define rules for function call expressions.-
arguments
(off by default) enforces indentation level for arguments in a call expression. This can either be a number indicating indentation level, or the string"first"
indicating that all arguments of the expression must be aligned with the first argument.
-
-
"ArrayExpression"
(default: 1) enforces indentation level for elements in arrays. It can also be set to the string"first"
, indicating that all the elements in the array should be aligned with the first element. -
"ObjectExpression"
(default: 1) enforces indentation level for properties in objects. It can be set to the string"first"
, indicating that all properties in the object should be aligned with the first property.
Level of indentation denotes the multiple of the indent specified. Example:
- Indent of 4 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 8 spaces. - Indent of 2 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 4 spaces. - Indent of 2 spaces with
VariableDeclarator
set to{"var": 2, "let": 2, "const": 3}
will indent the multi-line variable declarations with 4 spaces forvar
andlet
, 6 spaces forconst
statements. - Indent of tab with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 2 tabs. - Indent of 2 spaces with
SwitchCase
set to0
will not indentcase
clauses with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to1
will indentcase
clauses with 2 spaces with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to2
will indentcase
clauses with 4 spaces with respect toswitch
statements. - Indent of tab with
SwitchCase
set to2
will indentcase
clauses with 2 tabs with respect toswitch
statements. - Indent of 2 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 2 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 2 spaces. - Indent of 2 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 4 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 8 spaces.
tab
Examples of incorrect code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
/*tab*/b=c;
/*tab*/function foo(d) {
/*tab*//*tab*/e=f;
/*tab*/}
}
SwitchCase
Examples of incorrect code for this rule with the 2, { "SwitchCase": 1 }
options:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
Examples of correct code for this rule with the 2, { "SwitchCase": 1 }
option:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
VariableDeclarator
Examples of incorrect code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 2 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 2 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
outerIIFEBody
Examples of incorrect code for this rule with the options 2, { "outerIIFEBody": 0 }
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
Examples of correct code for this rule with the options 2, {"outerIIFEBody": 0}
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
MemberExpression
Examples of incorrect code for this rule with the 2, { "MemberExpression": 1 }
options:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz()
Examples of correct code for this rule with the 2, { "MemberExpression": 1 }
option:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz();
// Any indentation is permitted in variable declarations and assignments.
var bip = aardvark.badger
.coyote;
FunctionDeclaration
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
FunctionExpression
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
CallExpression
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
ArrayExpression
Examples of incorrect code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of incorrect code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
ObjectExpression
Examples of incorrect code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of correct code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of incorrect code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Examples of correct code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Compatibility
-
JSHint:
indent
- JSCS: validateIndentation Source: http://eslint.org/docs/rules/
Expected indentation of 6 spaces but found 8. Open
editor.on('blur', onBlur);
- Read upRead up
- Exclude checks
enforce consistent indentation (indent)
There are several common guidelines which require specific indentation of nested blocks and statements, like:
function hello(indentSize, type) {
if (indentSize === 4 && type !== 'tab') {
console.log('Each next indentation will increase on 4 spaces');
}
}
These are the most common scenarios recommended in different style guides:
- Two spaces, not longer and no tabs: Google, npm, Node.js, Idiomatic, Felix
- Tabs: jQuery
- Four spaces: Crockford
Rule Details
This rule enforces a consistent indentation style. The default style is 4 spaces
.
Options
This rule has a mixed option:
For example, for 2-space indentation:
{
"indent": ["error", 2]
}
Or for tabbed indentation:
{
"indent": ["error", "tab"]
}
Examples of incorrect code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
This rule has an object option:
-
"SwitchCase"
(default: 0) enforces indentation level forcase
clauses inswitch
statements -
"VariableDeclarator"
(default: 1) enforces indentation level forvar
declarators; can also take an object to define separate rules forvar
,let
andconst
declarations. -
"outerIIFEBody"
(default: 1) enforces indentation level for file-level IIFEs. -
"MemberExpression"
(off by default) enforces indentation level for multi-line property chains (except in variable declarations and assignments) -
"FunctionDeclaration"
takes an object to define rules for function declarations.-
parameters
(off by default) enforces indentation level for parameters in a function declaration. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the declaration must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function declaration.
-
-
"FunctionExpression"
takes an object to define rules for function expressions.-
parameters
(off by default) enforces indentation level for parameters in a function expression. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the expression must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function expression.
-
-
"CallExpression"
takes an object to define rules for function call expressions.-
arguments
(off by default) enforces indentation level for arguments in a call expression. This can either be a number indicating indentation level, or the string"first"
indicating that all arguments of the expression must be aligned with the first argument.
-
-
"ArrayExpression"
(default: 1) enforces indentation level for elements in arrays. It can also be set to the string"first"
, indicating that all the elements in the array should be aligned with the first element. -
"ObjectExpression"
(default: 1) enforces indentation level for properties in objects. It can be set to the string"first"
, indicating that all properties in the object should be aligned with the first property.
Level of indentation denotes the multiple of the indent specified. Example:
- Indent of 4 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 8 spaces. - Indent of 2 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 4 spaces. - Indent of 2 spaces with
VariableDeclarator
set to{"var": 2, "let": 2, "const": 3}
will indent the multi-line variable declarations with 4 spaces forvar
andlet
, 6 spaces forconst
statements. - Indent of tab with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 2 tabs. - Indent of 2 spaces with
SwitchCase
set to0
will not indentcase
clauses with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to1
will indentcase
clauses with 2 spaces with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to2
will indentcase
clauses with 4 spaces with respect toswitch
statements. - Indent of tab with
SwitchCase
set to2
will indentcase
clauses with 2 tabs with respect toswitch
statements. - Indent of 2 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 2 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 2 spaces. - Indent of 2 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 4 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 8 spaces.
tab
Examples of incorrect code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
/*tab*/b=c;
/*tab*/function foo(d) {
/*tab*//*tab*/e=f;
/*tab*/}
}
SwitchCase
Examples of incorrect code for this rule with the 2, { "SwitchCase": 1 }
options:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
Examples of correct code for this rule with the 2, { "SwitchCase": 1 }
option:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
VariableDeclarator
Examples of incorrect code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 2 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 2 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
outerIIFEBody
Examples of incorrect code for this rule with the options 2, { "outerIIFEBody": 0 }
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
Examples of correct code for this rule with the options 2, {"outerIIFEBody": 0}
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
MemberExpression
Examples of incorrect code for this rule with the 2, { "MemberExpression": 1 }
options:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz()
Examples of correct code for this rule with the 2, { "MemberExpression": 1 }
option:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz();
// Any indentation is permitted in variable declarations and assignments.
var bip = aardvark.badger
.coyote;
FunctionDeclaration
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
FunctionExpression
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
CallExpression
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
ArrayExpression
Examples of incorrect code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of incorrect code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
ObjectExpression
Examples of incorrect code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of correct code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of incorrect code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Examples of correct code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Compatibility
-
JSHint:
indent
- JSCS: validateIndentation Source: http://eslint.org/docs/rules/
Expected indentation of 6 spaces but found 8. Open
var placeholder_text = editor.getElement().getAttribute("placeholder") || editor.settings.placeholder;
- Read upRead up
- Exclude checks
enforce consistent indentation (indent)
There are several common guidelines which require specific indentation of nested blocks and statements, like:
function hello(indentSize, type) {
if (indentSize === 4 && type !== 'tab') {
console.log('Each next indentation will increase on 4 spaces');
}
}
These are the most common scenarios recommended in different style guides:
- Two spaces, not longer and no tabs: Google, npm, Node.js, Idiomatic, Felix
- Tabs: jQuery
- Four spaces: Crockford
Rule Details
This rule enforces a consistent indentation style. The default style is 4 spaces
.
Options
This rule has a mixed option:
For example, for 2-space indentation:
{
"indent": ["error", 2]
}
Or for tabbed indentation:
{
"indent": ["error", "tab"]
}
Examples of incorrect code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
This rule has an object option:
-
"SwitchCase"
(default: 0) enforces indentation level forcase
clauses inswitch
statements -
"VariableDeclarator"
(default: 1) enforces indentation level forvar
declarators; can also take an object to define separate rules forvar
,let
andconst
declarations. -
"outerIIFEBody"
(default: 1) enforces indentation level for file-level IIFEs. -
"MemberExpression"
(off by default) enforces indentation level for multi-line property chains (except in variable declarations and assignments) -
"FunctionDeclaration"
takes an object to define rules for function declarations.-
parameters
(off by default) enforces indentation level for parameters in a function declaration. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the declaration must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function declaration.
-
-
"FunctionExpression"
takes an object to define rules for function expressions.-
parameters
(off by default) enforces indentation level for parameters in a function expression. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the expression must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function expression.
-
-
"CallExpression"
takes an object to define rules for function call expressions.-
arguments
(off by default) enforces indentation level for arguments in a call expression. This can either be a number indicating indentation level, or the string"first"
indicating that all arguments of the expression must be aligned with the first argument.
-
-
"ArrayExpression"
(default: 1) enforces indentation level for elements in arrays. It can also be set to the string"first"
, indicating that all the elements in the array should be aligned with the first element. -
"ObjectExpression"
(default: 1) enforces indentation level for properties in objects. It can be set to the string"first"
, indicating that all properties in the object should be aligned with the first property.
Level of indentation denotes the multiple of the indent specified. Example:
- Indent of 4 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 8 spaces. - Indent of 2 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 4 spaces. - Indent of 2 spaces with
VariableDeclarator
set to{"var": 2, "let": 2, "const": 3}
will indent the multi-line variable declarations with 4 spaces forvar
andlet
, 6 spaces forconst
statements. - Indent of tab with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 2 tabs. - Indent of 2 spaces with
SwitchCase
set to0
will not indentcase
clauses with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to1
will indentcase
clauses with 2 spaces with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to2
will indentcase
clauses with 4 spaces with respect toswitch
statements. - Indent of tab with
SwitchCase
set to2
will indentcase
clauses with 2 tabs with respect toswitch
statements. - Indent of 2 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 2 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 2 spaces. - Indent of 2 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 4 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 8 spaces.
tab
Examples of incorrect code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
/*tab*/b=c;
/*tab*/function foo(d) {
/*tab*//*tab*/e=f;
/*tab*/}
}
SwitchCase
Examples of incorrect code for this rule with the 2, { "SwitchCase": 1 }
options:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
Examples of correct code for this rule with the 2, { "SwitchCase": 1 }
option:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
VariableDeclarator
Examples of incorrect code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 2 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 2 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
outerIIFEBody
Examples of incorrect code for this rule with the options 2, { "outerIIFEBody": 0 }
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
Examples of correct code for this rule with the options 2, {"outerIIFEBody": 0}
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
MemberExpression
Examples of incorrect code for this rule with the 2, { "MemberExpression": 1 }
options:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz()
Examples of correct code for this rule with the 2, { "MemberExpression": 1 }
option:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz();
// Any indentation is permitted in variable declarations and assignments.
var bip = aardvark.badger
.coyote;
FunctionDeclaration
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
FunctionExpression
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
CallExpression
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
ArrayExpression
Examples of incorrect code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of incorrect code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
ObjectExpression
Examples of incorrect code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of correct code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of incorrect code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Examples of correct code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Compatibility
-
JSHint:
indent
- JSCS: validateIndentation Source: http://eslint.org/docs/rules/
Expected indentation of 10 spaces but found 12. Open
editor.execCommand('mceFocus', false);
- Read upRead up
- Exclude checks
enforce consistent indentation (indent)
There are several common guidelines which require specific indentation of nested blocks and statements, like:
function hello(indentSize, type) {
if (indentSize === 4 && type !== 'tab') {
console.log('Each next indentation will increase on 4 spaces');
}
}
These are the most common scenarios recommended in different style guides:
- Two spaces, not longer and no tabs: Google, npm, Node.js, Idiomatic, Felix
- Tabs: jQuery
- Four spaces: Crockford
Rule Details
This rule enforces a consistent indentation style. The default style is 4 spaces
.
Options
This rule has a mixed option:
For example, for 2-space indentation:
{
"indent": ["error", 2]
}
Or for tabbed indentation:
{
"indent": ["error", "tab"]
}
Examples of incorrect code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
This rule has an object option:
-
"SwitchCase"
(default: 0) enforces indentation level forcase
clauses inswitch
statements -
"VariableDeclarator"
(default: 1) enforces indentation level forvar
declarators; can also take an object to define separate rules forvar
,let
andconst
declarations. -
"outerIIFEBody"
(default: 1) enforces indentation level for file-level IIFEs. -
"MemberExpression"
(off by default) enforces indentation level for multi-line property chains (except in variable declarations and assignments) -
"FunctionDeclaration"
takes an object to define rules for function declarations.-
parameters
(off by default) enforces indentation level for parameters in a function declaration. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the declaration must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function declaration.
-
-
"FunctionExpression"
takes an object to define rules for function expressions.-
parameters
(off by default) enforces indentation level for parameters in a function expression. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the expression must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function expression.
-
-
"CallExpression"
takes an object to define rules for function call expressions.-
arguments
(off by default) enforces indentation level for arguments in a call expression. This can either be a number indicating indentation level, or the string"first"
indicating that all arguments of the expression must be aligned with the first argument.
-
-
"ArrayExpression"
(default: 1) enforces indentation level for elements in arrays. It can also be set to the string"first"
, indicating that all the elements in the array should be aligned with the first element. -
"ObjectExpression"
(default: 1) enforces indentation level for properties in objects. It can be set to the string"first"
, indicating that all properties in the object should be aligned with the first property.
Level of indentation denotes the multiple of the indent specified. Example:
- Indent of 4 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 8 spaces. - Indent of 2 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 4 spaces. - Indent of 2 spaces with
VariableDeclarator
set to{"var": 2, "let": 2, "const": 3}
will indent the multi-line variable declarations with 4 spaces forvar
andlet
, 6 spaces forconst
statements. - Indent of tab with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 2 tabs. - Indent of 2 spaces with
SwitchCase
set to0
will not indentcase
clauses with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to1
will indentcase
clauses with 2 spaces with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to2
will indentcase
clauses with 4 spaces with respect toswitch
statements. - Indent of tab with
SwitchCase
set to2
will indentcase
clauses with 2 tabs with respect toswitch
statements. - Indent of 2 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 2 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 2 spaces. - Indent of 2 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 4 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 8 spaces.
tab
Examples of incorrect code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
/*tab*/b=c;
/*tab*/function foo(d) {
/*tab*//*tab*/e=f;
/*tab*/}
}
SwitchCase
Examples of incorrect code for this rule with the 2, { "SwitchCase": 1 }
options:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
Examples of correct code for this rule with the 2, { "SwitchCase": 1 }
option:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
VariableDeclarator
Examples of incorrect code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 2 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 2 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
outerIIFEBody
Examples of incorrect code for this rule with the options 2, { "outerIIFEBody": 0 }
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
Examples of correct code for this rule with the options 2, {"outerIIFEBody": 0}
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
MemberExpression
Examples of incorrect code for this rule with the 2, { "MemberExpression": 1 }
options:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz()
Examples of correct code for this rule with the 2, { "MemberExpression": 1 }
option:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz();
// Any indentation is permitted in variable declarations and assignments.
var bip = aardvark.badger
.coyote;
FunctionDeclaration
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
FunctionExpression
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
CallExpression
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
ArrayExpression
Examples of incorrect code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of incorrect code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
ObjectExpression
Examples of incorrect code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of correct code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of incorrect code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Examples of correct code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Compatibility
-
JSHint:
indent
- JSCS: validateIndentation Source: http://eslint.org/docs/rules/
Missing space before opening brace. Open
function onKeydown(){
- Read upRead up
- Exclude checks
Require Or Disallow Space Before Blocks (space-before-blocks)
Consistency is an important part of any style guide. While it is a personal preference where to put the opening brace of blocks, it should be consistent across a whole project. Having an inconsistent style distracts the reader from seeing the important parts of the code.
Rule Details
This rule will enforce consistency of spacing before blocks. It is only applied on blocks that don’t begin on a new line.
- This rule ignores spacing which is between
=>
and a block. The spacing is handled by thearrow-spacing
rule. - This rule ignores spacing which is between a keyword and a block. The spacing is handled by the
keyword-spacing
rule.
Options
This rule takes one argument. If it is "always"
then blocks must always have at least one preceding space. If "never"
then all blocks should never have any preceding space. If different spacing is desired for function
blocks, keyword blocks and classes, an optional configuration object can be passed as the rule argument to
configure the cases separately.
( e.g. { "functions": "never", "keywords": "always", "classes": "always" }
)
The default is "always"
.
"always"
Examples of incorrect code for this rule with the "always" option:
/*eslint space-before-blocks: "error"*/
if (a){
b();
}
function a(){}
for (;;){
b();
}
try {} catch(a){}
class Foo{
constructor(){}
}
Examples of correct code for this rule with the "always" option:
/*eslint space-before-blocks: "error"*/
if (a) {
b();
}
if (a) {
b();
} else{ /*no error. this is checked by `keyword-spacing` rule.*/
c();
}
function a() {}
for (;;) {
b();
}
try {} catch(a) {}
"never"
Examples of incorrect code for this rule with the "never" option:
/*eslint space-before-blocks: ["error", "never"]*/
if (a) {
b();
}
function a() {}
for (;;) {
b();
}
try {} catch(a) {}
Examples of correct code for this rule with the "never" option:
/*eslint space-before-blocks: ["error", "never"]*/
if (a){
b();
}
function a(){}
for (;;){
b();
}
try{} catch(a){}
class Foo{
constructor(){}
}
Examples of incorrect code for this rule when configured { "functions": "never", "keywords": "always", "classes": "never" }
:
/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "always", "classes": "never" }]*/
/*eslint-env es6*/
function a() {}
try {} catch(a){}
class Foo{
constructor() {}
}
Examples of correct code for this rule when configured { "functions": "never", "keywords": "always", "classes": "never" }
:
/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "always", "classes": "never" }]*/
/*eslint-env es6*/
for (;;) {
// ...
}
describe(function(){
// ...
});
class Foo {
constructor(){}
}
Examples of incorrect code for this rule when configured { "functions": "always", "keywords": "never", "classes": "never" }
:
/*eslint space-before-blocks: ["error", { "functions": "always", "keywords": "never", "classes": "never" }]*/
/*eslint-env es6*/
function a(){}
try {} catch(a) {}
class Foo {
constructor(){}
}
Examples of correct code for this rule when configured { "functions": "always", "keywords": "never", "classes": "never" }
:
/*eslint space-before-blocks: ["error", { "functions": "always", "keywords": "never", "classes": "never" }]*/
/*eslint-env es6*/
if (a){
b();
}
var a = function() {}
class Foo{
constructor() {}
}
Examples of incorrect code for this rule when configured { "functions": "never", "keywords": "never", "classes": "always" }
:
/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "never", "classes": "always" }]*/
/*eslint-env es6*/
class Foo{
constructor(){}
}
Examples of correct code for this rule when configured { "functions": "never", "keywords": "never", "classes": "always" }
:
/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "never", "classes": "always" }]*/
/*eslint-env es6*/
class Foo {
constructor(){}
}
When Not To Use It
You can turn this rule off if you are not concerned with the consistency of spacing before blocks.
Related Rules
- [keyword-spacing](keyword-spacing.md)
- [arrow-spacing](arrow-spacing.md)
- [brace-style](brace-style.md) Source: http://eslint.org/docs/rules/
Expected indentation of 14 spaces but found 16. Open
label.hide();
- Read upRead up
- Exclude checks
enforce consistent indentation (indent)
There are several common guidelines which require specific indentation of nested blocks and statements, like:
function hello(indentSize, type) {
if (indentSize === 4 && type !== 'tab') {
console.log('Each next indentation will increase on 4 spaces');
}
}
These are the most common scenarios recommended in different style guides:
- Two spaces, not longer and no tabs: Google, npm, Node.js, Idiomatic, Felix
- Tabs: jQuery
- Four spaces: Crockford
Rule Details
This rule enforces a consistent indentation style. The default style is 4 spaces
.
Options
This rule has a mixed option:
For example, for 2-space indentation:
{
"indent": ["error", 2]
}
Or for tabbed indentation:
{
"indent": ["error", "tab"]
}
Examples of incorrect code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
This rule has an object option:
-
"SwitchCase"
(default: 0) enforces indentation level forcase
clauses inswitch
statements -
"VariableDeclarator"
(default: 1) enforces indentation level forvar
declarators; can also take an object to define separate rules forvar
,let
andconst
declarations. -
"outerIIFEBody"
(default: 1) enforces indentation level for file-level IIFEs. -
"MemberExpression"
(off by default) enforces indentation level for multi-line property chains (except in variable declarations and assignments) -
"FunctionDeclaration"
takes an object to define rules for function declarations.-
parameters
(off by default) enforces indentation level for parameters in a function declaration. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the declaration must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function declaration.
-
-
"FunctionExpression"
takes an object to define rules for function expressions.-
parameters
(off by default) enforces indentation level for parameters in a function expression. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the expression must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function expression.
-
-
"CallExpression"
takes an object to define rules for function call expressions.-
arguments
(off by default) enforces indentation level for arguments in a call expression. This can either be a number indicating indentation level, or the string"first"
indicating that all arguments of the expression must be aligned with the first argument.
-
-
"ArrayExpression"
(default: 1) enforces indentation level for elements in arrays. It can also be set to the string"first"
, indicating that all the elements in the array should be aligned with the first element. -
"ObjectExpression"
(default: 1) enforces indentation level for properties in objects. It can be set to the string"first"
, indicating that all properties in the object should be aligned with the first property.
Level of indentation denotes the multiple of the indent specified. Example:
- Indent of 4 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 8 spaces. - Indent of 2 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 4 spaces. - Indent of 2 spaces with
VariableDeclarator
set to{"var": 2, "let": 2, "const": 3}
will indent the multi-line variable declarations with 4 spaces forvar
andlet
, 6 spaces forconst
statements. - Indent of tab with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 2 tabs. - Indent of 2 spaces with
SwitchCase
set to0
will not indentcase
clauses with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to1
will indentcase
clauses with 2 spaces with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to2
will indentcase
clauses with 4 spaces with respect toswitch
statements. - Indent of tab with
SwitchCase
set to2
will indentcase
clauses with 2 tabs with respect toswitch
statements. - Indent of 2 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 2 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 2 spaces. - Indent of 2 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 4 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 8 spaces.
tab
Examples of incorrect code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
/*tab*/b=c;
/*tab*/function foo(d) {
/*tab*//*tab*/e=f;
/*tab*/}
}
SwitchCase
Examples of incorrect code for this rule with the 2, { "SwitchCase": 1 }
options:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
Examples of correct code for this rule with the 2, { "SwitchCase": 1 }
option:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
VariableDeclarator
Examples of incorrect code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 2 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 2 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
outerIIFEBody
Examples of incorrect code for this rule with the options 2, { "outerIIFEBody": 0 }
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
Examples of correct code for this rule with the options 2, {"outerIIFEBody": 0}
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
MemberExpression
Examples of incorrect code for this rule with the 2, { "MemberExpression": 1 }
options:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz()
Examples of correct code for this rule with the 2, { "MemberExpression": 1 }
option:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz();
// Any indentation is permitted in variable declarations and assignments.
var bip = aardvark.badger
.coyote;
FunctionDeclaration
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
FunctionExpression
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
CallExpression
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
ArrayExpression
Examples of incorrect code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of incorrect code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
ObjectExpression
Examples of incorrect code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of correct code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of incorrect code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Examples of correct code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Compatibility
-
JSHint:
indent
- JSCS: validateIndentation Source: http://eslint.org/docs/rules/
Missing space before function parentheses. Open
var Label = function(){
- Read upRead up
- Exclude checks
Require or disallow a space before function parenthesis (space-before-function-paren)
When formatting a function, whitespace is allowed between the function name or function
keyword and the opening paren. Named functions also require a space between the function
keyword and the function name, but anonymous functions require no whitespace. For example:
function withoutSpace(x) {
// ...
}
function withSpace (x) {
// ...
}
var anonymousWithoutSpace = function() {};
var anonymousWithSpace = function () {};
Style guides may require a space after the function
keyword for anonymous functions, while others specify no whitespace. Similarly, the space after a function name may or may not be required.
Rule Details
This rule aims to enforce consistent spacing before function parentheses and as such, will warn whenever whitespace doesn't match the preferences specified.
Options
This rule has a string option or an object option:
{
"space-before-function-paren": ["error", "always"],
// or
"space-before-function-paren": ["error", {
"anonymous": "always",
"named": "always",
"asyncArrow": "ignore"
}],
}
-
always
(default) requires a space followed by the(
of arguments. -
never
disallows any space followed by the(
of arguments.
The string option does not check async arrow function expressions for backward compatibility.
You can also use a separate option for each type of function.
Each of the following options can be set to "always"
, "never"
, or "ignore"
.
Default is "always"
basically.
-
anonymous
is for anonymous function expressions (e.g.function () {}
). -
named
is for named function expressions (e.g.function foo () {}
). -
asyncArrow
is for async arrow function expressions (e.g.async () => {}
).asyncArrow
is set to"ignore"
by default for backwards compatibility.
"always"
Examples of incorrect code for this rule with the default "always"
option:
/*eslint space-before-function-paren: "error"*/
/*eslint-env es6*/
function foo() {
// ...
}
var bar = function() {
// ...
};
var bar = function foo() {
// ...
};
class Foo {
constructor() {
// ...
}
}
var foo = {
bar() {
// ...
}
};
Examples of correct code for this rule with the default "always"
option:
/*eslint space-before-function-paren: "error"*/
/*eslint-env es6*/
function foo () {
// ...
}
var bar = function () {
// ...
};
var bar = function foo () {
// ...
};
class Foo {
constructor () {
// ...
}
}
var foo = {
bar () {
// ...
}
};
// async arrow function expressions are ignored by default.
var foo = async () => 1
var foo = async() => 1
"never"
Examples of incorrect code for this rule with the "never"
option:
/*eslint space-before-function-paren: ["error", "never"]*/
/*eslint-env es6*/
function foo () {
// ...
}
var bar = function () {
// ...
};
var bar = function foo () {
// ...
};
class Foo {
constructor () {
// ...
}
}
var foo = {
bar () {
// ...
}
};
Examples of correct code for this rule with the "never"
option:
/*eslint space-before-function-paren: ["error", "never"]*/
/*eslint-env es6*/
function foo() {
// ...
}
var bar = function() {
// ...
};
var bar = function foo() {
// ...
};
class Foo {
constructor() {
// ...
}
}
var foo = {
bar() {
// ...
}
};
// async arrow function expressions are ignored by default.
var foo = async () => 1
var foo = async() => 1
{"anonymous": "always", "named": "never", "asyncArrow": "always"}
Examples of incorrect code for this rule with the {"anonymous": "always", "named": "never", "asyncArrow": "always"}
option:
/*eslint space-before-function-paren: ["error", {"anonymous": "always", "named": "never", "asyncArrow": "always"}]*/
/*eslint-env es6*/
function foo () {
// ...
}
var bar = function() {
// ...
};
class Foo {
constructor () {
// ...
}
}
var foo = {
bar () {
// ...
}
};
var foo = async(a) => await a
Examples of correct code for this rule with the {"anonymous": "always", "named": "never", "asyncArrow": "always"}
option:
/*eslint space-before-function-paren: ["error", {"anonymous": "always", "named": "never", "asyncArrow": "always"}]*/
/*eslint-env es6*/
function foo() {
// ...
}
var bar = function () {
// ...
};
class Foo {
constructor() {
// ...
}
}
var foo = {
bar() {
// ...
}
};
var foo = async (a) => await a
{"anonymous": "never", "named": "always"}
Examples of incorrect code for this rule with the {"anonymous": "never", "named": "always"}
option:
/*eslint space-before-function-paren: ["error", { "anonymous": "never", "named": "always" }]*/
/*eslint-env es6*/
function foo() {
// ...
}
var bar = function () {
// ...
};
class Foo {
constructor() {
// ...
}
}
var foo = {
bar() {
// ...
}
};
Examples of correct code for this rule with the {"anonymous": "never", "named": "always"}
option:
/*eslint space-before-function-paren: ["error", { "anonymous": "never", "named": "always" }]*/
/*eslint-env es6*/
function foo () {
// ...
}
var bar = function() {
// ...
};
class Foo {
constructor () {
// ...
}
}
var foo = {
bar () {
// ...
}
};
{"anonymous": "ignore", "named": "always"}
Examples of incorrect code for this rule with the {"anonymous": "ignore", "named": "always"}
option:
/*eslint space-before-function-paren: ["error", { "anonymous": "ignore", "named": "always" }]*/
/*eslint-env es6*/
function foo() {
// ...
}
class Foo {
constructor() {
// ...
}
}
var foo = {
bar() {
// ...
}
};
Examples of correct code for this rule with the {"anonymous": "ignore", "named": "always"}
option:
/*eslint space-before-function-paren: ["error", { "anonymous": "ignore", "named": "always" }]*/
/*eslint-env es6*/
var bar = function() {
// ...
};
var bar = function () {
// ...
};
function foo () {
// ...
}
class Foo {
constructor () {
// ...
}
}
var foo = {
bar () {
// ...
}
};
When Not To Use It
You can turn this rule off if you are not concerned with the consistency of spacing before function parenthesis.
Related Rules
- [space-after-keywords](space-after-keywords.md)
- [space-return-throw-case](space-return-throw-case.md) Source: http://eslint.org/docs/rules/
Expected indentation of 6 spaces but found 8. Open
var contentAreaContainer = editor.getContentAreaContainer();
- Read upRead up
- Exclude checks
enforce consistent indentation (indent)
There are several common guidelines which require specific indentation of nested blocks and statements, like:
function hello(indentSize, type) {
if (indentSize === 4 && type !== 'tab') {
console.log('Each next indentation will increase on 4 spaces');
}
}
These are the most common scenarios recommended in different style guides:
- Two spaces, not longer and no tabs: Google, npm, Node.js, Idiomatic, Felix
- Tabs: jQuery
- Four spaces: Crockford
Rule Details
This rule enforces a consistent indentation style. The default style is 4 spaces
.
Options
This rule has a mixed option:
For example, for 2-space indentation:
{
"indent": ["error", 2]
}
Or for tabbed indentation:
{
"indent": ["error", "tab"]
}
Examples of incorrect code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
This rule has an object option:
-
"SwitchCase"
(default: 0) enforces indentation level forcase
clauses inswitch
statements -
"VariableDeclarator"
(default: 1) enforces indentation level forvar
declarators; can also take an object to define separate rules forvar
,let
andconst
declarations. -
"outerIIFEBody"
(default: 1) enforces indentation level for file-level IIFEs. -
"MemberExpression"
(off by default) enforces indentation level for multi-line property chains (except in variable declarations and assignments) -
"FunctionDeclaration"
takes an object to define rules for function declarations.-
parameters
(off by default) enforces indentation level for parameters in a function declaration. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the declaration must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function declaration.
-
-
"FunctionExpression"
takes an object to define rules for function expressions.-
parameters
(off by default) enforces indentation level for parameters in a function expression. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the expression must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function expression.
-
-
"CallExpression"
takes an object to define rules for function call expressions.-
arguments
(off by default) enforces indentation level for arguments in a call expression. This can either be a number indicating indentation level, or the string"first"
indicating that all arguments of the expression must be aligned with the first argument.
-
-
"ArrayExpression"
(default: 1) enforces indentation level for elements in arrays. It can also be set to the string"first"
, indicating that all the elements in the array should be aligned with the first element. -
"ObjectExpression"
(default: 1) enforces indentation level for properties in objects. It can be set to the string"first"
, indicating that all properties in the object should be aligned with the first property.
Level of indentation denotes the multiple of the indent specified. Example:
- Indent of 4 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 8 spaces. - Indent of 2 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 4 spaces. - Indent of 2 spaces with
VariableDeclarator
set to{"var": 2, "let": 2, "const": 3}
will indent the multi-line variable declarations with 4 spaces forvar
andlet
, 6 spaces forconst
statements. - Indent of tab with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 2 tabs. - Indent of 2 spaces with
SwitchCase
set to0
will not indentcase
clauses with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to1
will indentcase
clauses with 2 spaces with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to2
will indentcase
clauses with 4 spaces with respect toswitch
statements. - Indent of tab with
SwitchCase
set to2
will indentcase
clauses with 2 tabs with respect toswitch
statements. - Indent of 2 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 2 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 2 spaces. - Indent of 2 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 4 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 8 spaces.
tab
Examples of incorrect code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
/*tab*/b=c;
/*tab*/function foo(d) {
/*tab*//*tab*/e=f;
/*tab*/}
}
SwitchCase
Examples of incorrect code for this rule with the 2, { "SwitchCase": 1 }
options:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
Examples of correct code for this rule with the 2, { "SwitchCase": 1 }
option:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
VariableDeclarator
Examples of incorrect code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 2 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 2 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
outerIIFEBody
Examples of incorrect code for this rule with the options 2, { "outerIIFEBody": 0 }
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
Examples of correct code for this rule with the options 2, {"outerIIFEBody": 0}
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
MemberExpression
Examples of incorrect code for this rule with the 2, { "MemberExpression": 1 }
options:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz()
Examples of correct code for this rule with the 2, { "MemberExpression": 1 }
option:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz();
// Any indentation is permitted in variable declarations and assignments.
var bip = aardvark.badger
.coyote;
FunctionDeclaration
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
FunctionExpression
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
CallExpression
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
ArrayExpression
Examples of incorrect code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of incorrect code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
ObjectExpression
Examples of incorrect code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of correct code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of incorrect code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Examples of correct code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Compatibility
-
JSHint:
indent
- JSCS: validateIndentation Source: http://eslint.org/docs/rules/
Identifier 'placeholder_attrs' is not in camel case. Open
var placeholder_attrs = editor.settings.placeholder_attrs || {style: {position: 'absolute', top:'5px', left:0, color: '#888', padding: '1%', width:'98%', overflow: 'hidden', 'white-space': 'pre-wrap'} };
- Read upRead up
- Exclude checks
Require Camelcase (camelcase)
When it comes to naming variables, style guides generally fall into one of two camps: camelcase (variableName
) and underscores (variable_name
). This rule focuses on using the camelcase approach. If your style guide calls for camelcasing your variable names, then this rule is for you!
Rule Details
This rule looks for any underscores (_
) located within the source code. It ignores leading and trailing underscores and only checks those in the middle of a variable name. If ESLint decides that the variable is a constant (all uppercase), then no warning will be thrown. Otherwise, a warning will be thrown. This rule only flags definitions and assignments but not function calls. In case of ES6 import
statements, this rule only targets the name of the variable that will be imported into the local module scope.
Options
This rule has an object option:
-
"properties": "always"
(default) enforces camelcase style for property names -
"properties": "never"
does not check property names
always
Examples of incorrect code for this rule with the default { "properties": "always" }
option:
/*eslint camelcase: "error"*/
import { no_camelcased } from "external-module"
var my_favorite_color = "#112C85";
function do_something() {
// ...
}
obj.do_something = function() {
// ...
};
var obj = {
my_pref: 1
};
Examples of correct code for this rule with the default { "properties": "always" }
option:
/*eslint camelcase: "error"*/
import { no_camelcased as camelCased } from "external-module";
var myFavoriteColor = "#112C85";
var _myFavoriteColor = "#112C85";
var myFavoriteColor_ = "#112C85";
var MY_FAVORITE_COLOR = "#112C85";
var foo = bar.baz_boom;
var foo = { qux: bar.baz_boom };
obj.do_something();
do_something();
new do_something();
var { category_id: category } = query;
never
Examples of correct code for this rule with the { "properties": "never" }
option:
/*eslint camelcase: ["error", {properties: "never"}]*/
var obj = {
my_pref: 1
};
When Not To Use It
If you have established coding standards using a different naming convention (separating words with underscores), turn this rule off. Source: http://eslint.org/docs/rules/
Expected indentation of 6 spaces but found 8. Open
tinymce.DOM.setStyle(contentAreaContainer, 'position', 'relative');
- Read upRead up
- Exclude checks
enforce consistent indentation (indent)
There are several common guidelines which require specific indentation of nested blocks and statements, like:
function hello(indentSize, type) {
if (indentSize === 4 && type !== 'tab') {
console.log('Each next indentation will increase on 4 spaces');
}
}
These are the most common scenarios recommended in different style guides:
- Two spaces, not longer and no tabs: Google, npm, Node.js, Idiomatic, Felix
- Tabs: jQuery
- Four spaces: Crockford
Rule Details
This rule enforces a consistent indentation style. The default style is 4 spaces
.
Options
This rule has a mixed option:
For example, for 2-space indentation:
{
"indent": ["error", 2]
}
Or for tabbed indentation:
{
"indent": ["error", "tab"]
}
Examples of incorrect code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
This rule has an object option:
-
"SwitchCase"
(default: 0) enforces indentation level forcase
clauses inswitch
statements -
"VariableDeclarator"
(default: 1) enforces indentation level forvar
declarators; can also take an object to define separate rules forvar
,let
andconst
declarations. -
"outerIIFEBody"
(default: 1) enforces indentation level for file-level IIFEs. -
"MemberExpression"
(off by default) enforces indentation level for multi-line property chains (except in variable declarations and assignments) -
"FunctionDeclaration"
takes an object to define rules for function declarations.-
parameters
(off by default) enforces indentation level for parameters in a function declaration. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the declaration must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function declaration.
-
-
"FunctionExpression"
takes an object to define rules for function expressions.-
parameters
(off by default) enforces indentation level for parameters in a function expression. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the expression must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function expression.
-
-
"CallExpression"
takes an object to define rules for function call expressions.-
arguments
(off by default) enforces indentation level for arguments in a call expression. This can either be a number indicating indentation level, or the string"first"
indicating that all arguments of the expression must be aligned with the first argument.
-
-
"ArrayExpression"
(default: 1) enforces indentation level for elements in arrays. It can also be set to the string"first"
, indicating that all the elements in the array should be aligned with the first element. -
"ObjectExpression"
(default: 1) enforces indentation level for properties in objects. It can be set to the string"first"
, indicating that all properties in the object should be aligned with the first property.
Level of indentation denotes the multiple of the indent specified. Example:
- Indent of 4 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 8 spaces. - Indent of 2 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 4 spaces. - Indent of 2 spaces with
VariableDeclarator
set to{"var": 2, "let": 2, "const": 3}
will indent the multi-line variable declarations with 4 spaces forvar
andlet
, 6 spaces forconst
statements. - Indent of tab with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 2 tabs. - Indent of 2 spaces with
SwitchCase
set to0
will not indentcase
clauses with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to1
will indentcase
clauses with 2 spaces with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to2
will indentcase
clauses with 4 spaces with respect toswitch
statements. - Indent of tab with
SwitchCase
set to2
will indentcase
clauses with 2 tabs with respect toswitch
statements. - Indent of 2 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 2 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 2 spaces. - Indent of 2 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 4 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 8 spaces.
tab
Examples of incorrect code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
/*tab*/b=c;
/*tab*/function foo(d) {
/*tab*//*tab*/e=f;
/*tab*/}
}
SwitchCase
Examples of incorrect code for this rule with the 2, { "SwitchCase": 1 }
options:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
Examples of correct code for this rule with the 2, { "SwitchCase": 1 }
option:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
VariableDeclarator
Examples of incorrect code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 2 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 2 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
outerIIFEBody
Examples of incorrect code for this rule with the options 2, { "outerIIFEBody": 0 }
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
Examples of correct code for this rule with the options 2, {"outerIIFEBody": 0}
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
MemberExpression
Examples of incorrect code for this rule with the 2, { "MemberExpression": 1 }
options:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz()
Examples of correct code for this rule with the 2, { "MemberExpression": 1 }
option:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz();
// Any indentation is permitted in variable declarations and assignments.
var bip = aardvark.badger
.coyote;
FunctionDeclaration
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
FunctionExpression
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
CallExpression
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
ArrayExpression
Examples of incorrect code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of incorrect code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
ObjectExpression
Examples of incorrect code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of correct code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of incorrect code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Examples of correct code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Compatibility
-
JSHint:
indent
- JSCS: validateIndentation Source: http://eslint.org/docs/rules/
Missing space before value for key 'left'. Open
var placeholder_attrs = editor.settings.placeholder_attrs || {style: {position: 'absolute', top:'5px', left:0, color: '#888', padding: '1%', width:'98%', overflow: 'hidden', 'white-space': 'pre-wrap'} };
- Read upRead up
- Exclude checks
enforce consistent spacing between keys and values in object literal properties (key-spacing)
This rule enforces spacing around the colon in object literal properties. It can verify each property individually, or it can ensure horizontal alignment of adjacent properties in an object literal.
Rule Details
This rule enforces consistent spacing between keys and values in object literal properties. In the case of long lines, it is acceptable to add a new line wherever whitespace is allowed.
Options
This rule has an object option:
-
"beforeColon": false
(default) disallows spaces between the key and the colon in object literals. -
"beforeColon": true
requires at least one space between the key and the colon in object literals. -
"afterColon": true
(default) requires at least one space between the colon and the value in object literals. -
"afterColon": false
disallows spaces between the colon and the value in object literals. -
"mode": "strict"
(default) enforces exactly one space before or after colons in object literals. -
"mode": "minimum"
enforces one or more spaces before or after colons in object literals. -
"align": "value"
enforces horizontal alignment of values in object literals. -
"align": "colon"
enforces horizontal alignment of both colons and values in object literals. -
"align"
with an object value allows for fine-grained spacing when values are being aligned in object literals. -
"singleLine"
specifies a spacing style for single-line object literals. -
"multiLine"
specifies a spacing style for multi-line object literals.
Please note that you can either use the top-level options or the grouped options (singleLine
and multiLine
) but not both.
beforeColon
Examples of incorrect code for this rule with the default { "beforeColon": false }
option:
/*eslint key-spacing: ["error", { "beforeColon": false }]*/
var obj = { "foo" : 42 };
Examples of correct code for this rule with the default { "beforeColon": false }
option:
/*eslint key-spacing: ["error", { "beforeColon": false }]*/
var obj = { "foo": 42 };
Examples of incorrect code for this rule with the { "beforeColon": true }
option:
/*eslint key-spacing: ["error", { "beforeColon": true }]*/
var obj = { "foo": 42 };
Examples of correct code for this rule with the { "beforeColon": true }
option:
/*eslint key-spacing: ["error", { "beforeColon": true }]*/
var obj = { "foo" : 42 };
afterColon
Examples of incorrect code for this rule with the default { "afterColon": true }
option:
/*eslint key-spacing: ["error", { "afterColon": true }]*/
var obj = { "foo":42 };
Examples of correct code for this rule with the default { "afterColon": true }
option:
/*eslint key-spacing: ["error", { "afterColon": true }]*/
var obj = { "foo": 42 };
Examples of incorrect code for this rule with the { "afterColon": false }
option:
/*eslint key-spacing: ["error", { "afterColon": false }]*/
var obj = { "foo": 42 };
Examples of correct code for this rule with the { "afterColon": false }
option:
/*eslint key-spacing: ["error", { "afterColon": false }]*/
var obj = { "foo":42 };
mode
Examples of incorrect code for this rule with the default { "mode": "strict" }
option:
/*eslint key-spacing: ["error", { "mode": "strict" }]*/
call({
foobar: 42,
bat: 2 * 2
});
Examples of correct code for this rule with the default { "mode": "strict" }
option:
/*eslint key-spacing: ["error", { "mode": "strict" }]*/
call({
foobar: 42,
bat: 2 * 2
});
Examples of correct code for this rule with the { "mode": "minimum" }
option:
/*eslint key-spacing: ["error", { "mode": "minimum" }]*/
call({
foobar: 42,
bat: 2 * 2
});
align
Examples of incorrect code for this rule with the { "align": "value" }
option:
/*eslint key-spacing: ["error", { "align": "value" }]*/
var obj = {
a: value,
bcde: 42,
fg : foo()
};
Examples of correct code for this rule with the { "align": "value" }
option:
/*eslint key-spacing: ["error", { "align": "value" }]*/
var obj = {
a: value,
bcde: 42,
fg: foo(),
h: function() {
return this.a;
},
ijkl: 'Non-consecutive lines form a new group'
};
var obj = { a: "foo", longPropertyName: "bar" };
Examples of incorrect code for this rule with the { "align": "colon" }
option:
/*eslint key-spacing: ["error", { "align": "colon" }]*/
call({
foobar: 42,
bat: 2 * 2
});
Examples of correct code for this rule with the { "align": "colon" }
option:
/*eslint key-spacing: ["error", { "align": "colon" }]*/
call({
foobar: 42,
bat : 2 * 2
});
align
The align
option can take additional configuration through the beforeColon
, afterColon
, mode
, and on
options.
If align
is defined as an object, but not all of the parameters are provided, undefined parameters will default to the following:
// Defaults
align: {
"beforeColon": false,
"afterColon": true,
"on": "colon",
"mode": "strict"
}
Examples of correct code for this rule with sample { "align": { } }
options:
/*eslint key-spacing: ["error", {
"align": {
"beforeColon": true,
"afterColon": true,
"on": "colon"
}
}]*/
var obj = {
"one" : 1,
"seven" : 7
}
/*eslint key-spacing: ["error", {
"align": {
"beforeColon": false,
"afterColon": false,
"on": "value"
}
}]*/
var obj = {
"one": 1,
"seven":7
}
align and multiLine
The multiLine
and align
options can differ, which allows for fine-tuned control over the key-spacing
of your files. align
will not inherit from multiLine
if align
is configured as an object.
multiLine
is used any time an object literal spans multiple lines. The align
configuration is used when there is a group of properties in the same object. For example:
var myObj = {
key1: 1, // uses multiLine
key2: 2, // uses align (when defined)
key3: 3, // uses align (when defined)
key4: 4 // uses multiLine
}
Examples of incorrect code for this rule with sample { "align": { }, "multiLine": { } }
options:
/*eslint key-spacing: ["error", {
"multiLine": {
"beforeColon": false,
"afterColon":true
},
"align": {
"beforeColon": true,
"afterColon": true,
"on": "colon"
}
}]*/
var obj = {
"myObjectFunction": function() {
// Do something
},
"one" : 1,
"seven" : 7
}
Examples of correct code for this rule with sample { "align": { }, "multiLine": { } }
options:
/*eslint key-spacing: ["error", {
"multiLine": {
"beforeColon": false,
"afterColon": true
},
"align": {
"beforeColon": true,
"afterColon": true,
"on": "colon"
}
}]*/
var obj = {
"myObjectFunction": function() {
// Do something
//
}, // These are two separate groups, so no alignment between `myObjectFuction` and `one`
"one" : 1,
"seven" : 7 // `one` and `seven` are in their own group, and therefore aligned
}
singleLine and multiLine
Examples of correct code for this rule with sample { "singleLine": { }, "multiLine": { } }
options:
/*eslint "key-spacing": [2, {
"singleLine": {
"beforeColon": false,
"afterColon": true
},
"multiLine": {
"beforeColon": true,
"afterColon": true,
"align": "colon"
}
}]*/
var obj = { one: 1, "two": 2, three: 3 };
var obj2 = {
"two" : 2,
three : 3
};
When Not To Use It
If you have another convention for property spacing that might not be consistent with the available options, or if you want to permit multiple styles concurrently you can safely disable this rule. Source: http://eslint.org/docs/rules/
Missing semicolon. Open
}
- Read upRead up
- Exclude checks
require or disallow semicolons instead of ASI (semi)
JavaScript is unique amongst the C-like languages in that it doesn't require semicolons at the end of each statement. In many cases, the JavaScript engine can determine that a semicolon should be in a certain spot and will automatically add it. This feature is known as automatic semicolon insertion (ASI) and is considered one of the more controversial features of JavaScript. For example, the following lines are both valid:
var name = "ESLint"
var website = "eslint.org";
On the first line, the JavaScript engine will automatically insert a semicolon, so this is not considered a syntax error. The JavaScript engine still knows how to interpret the line and knows that the line end indicates the end of the statement.
In the debate over ASI, there are generally two schools of thought. The first is that we should treat ASI as if it didn't exist and always include semicolons manually. The rationale is that it's easier to always include semicolons than to try to remember when they are or are not required, and thus decreases the possibility of introducing an error.
However, the ASI mechanism can sometimes be tricky to people who are using semicolons. For example, consider this code:
return
{
name: "ESLint"
};
This may look like a return
statement that returns an object literal, however, the JavaScript engine will interpret this code as:
return;
{
name: "ESLint";
}
Effectively, a semicolon is inserted after the return
statement, causing the code below it (a labeled literal inside a block) to be unreachable. This rule and the [no-unreachable](no-unreachable.md) rule will protect your code from such cases.
On the other side of the argument are those who says that since semicolons are inserted automatically, they are optional and do not need to be inserted manually. However, the ASI mechanism can also be tricky to people who don't use semicolons. For example, consider this code:
var globalCounter = { }
(function () {
var n = 0
globalCounter.increment = function () {
return ++n
}
})()
In this example, a semicolon will not be inserted after the first line, causing a run-time error (because an empty object is called as if it's a function). The [no-unexpected-multiline](no-unexpected-multiline.md) rule can protect your code from such cases.
Although ASI allows for more freedom over your coding style, it can also make your code behave in an unexpected way, whether you use semicolons or not. Therefore, it is best to know when ASI takes place and when it does not, and have ESLint protect your code from these potentially unexpected cases. In short, as once described by Isaac Schlueter, a \n
character always ends a statement (just like a semicolon) unless one of the following is true:
- The statement has an unclosed paren, array literal, or object literal or ends in some other way that is not a valid way to end a statement. (For instance, ending with
.
or,
.) - The line is
--
or++
(in which case it will decrement/increment the next token.) - It is a
for()
,while()
,do
,if()
, orelse
, and there is no{
- The next line starts with
[
,(
,+
,*
,/
,-
,,
,.
, or some other binary operator that can only be found between two tokens in a single expression.
Rule Details
This rule enforces consistent use of semicolons.
Options
This rule has two options, a string option and an object option.
String option:
-
"always"
(default) requires semicolons at the end of statements -
"never"
disallows semicolons as the end of statements (except to disambiguate statements beginning with[
,(
,/
,+
, or-
)
Object option:
-
"omitLastInOneLineBlock": true
ignores the last semicolon in a block in which its braces (and therefore the content of the block) are in the same line
always
Examples of incorrect code for this rule with the default "always"
option:
/*eslint semi: ["error", "always"]*/
var name = "ESLint"
object.method = function() {
// ...
}
Examples of correct code for this rule with the default "always"
option:
/*eslint semi: "error"*/
var name = "ESLint";
object.method = function() {
// ...
};
never
Examples of incorrect code for this rule with the "never"
option:
/*eslint semi: ["error", "never"]*/
var name = "ESLint";
object.method = function() {
// ...
};
Examples of correct code for this rule with the "never"
option:
/*eslint semi: ["error", "never"]*/
var name = "ESLint"
object.method = function() {
// ...
}
var name = "ESLint"
;(function() {
// ...
})()
omitLastInOneLineBlock
Examples of additional correct code for this rule with the "always", { "omitLastInOneLineBlock": true }
options:
/*eslint semi: ["error", "always", { "omitLastInOneLineBlock": true}] */
if (foo) { bar() }
if (foo) { bar(); baz() }
When Not To Use It
If you do not want to enforce semicolon usage (or omission) in any particular way, then you can turn this rule off.
Further Reading
Related Rules
- [no-extra-semi](no-extra-semi.md)
- [no-unexpected-multiline](no-unexpected-multiline.md)
- [semi-spacing](semi-spacing.md) Source: http://eslint.org/docs/rules/
Missing space before function parentheses. Open
Label.prototype.hide = function(){
- Read upRead up
- Exclude checks
Require or disallow a space before function parenthesis (space-before-function-paren)
When formatting a function, whitespace is allowed between the function name or function
keyword and the opening paren. Named functions also require a space between the function
keyword and the function name, but anonymous functions require no whitespace. For example:
function withoutSpace(x) {
// ...
}
function withSpace (x) {
// ...
}
var anonymousWithoutSpace = function() {};
var anonymousWithSpace = function () {};
Style guides may require a space after the function
keyword for anonymous functions, while others specify no whitespace. Similarly, the space after a function name may or may not be required.
Rule Details
This rule aims to enforce consistent spacing before function parentheses and as such, will warn whenever whitespace doesn't match the preferences specified.
Options
This rule has a string option or an object option:
{
"space-before-function-paren": ["error", "always"],
// or
"space-before-function-paren": ["error", {
"anonymous": "always",
"named": "always",
"asyncArrow": "ignore"
}],
}
-
always
(default) requires a space followed by the(
of arguments. -
never
disallows any space followed by the(
of arguments.
The string option does not check async arrow function expressions for backward compatibility.
You can also use a separate option for each type of function.
Each of the following options can be set to "always"
, "never"
, or "ignore"
.
Default is "always"
basically.
-
anonymous
is for anonymous function expressions (e.g.function () {}
). -
named
is for named function expressions (e.g.function foo () {}
). -
asyncArrow
is for async arrow function expressions (e.g.async () => {}
).asyncArrow
is set to"ignore"
by default for backwards compatibility.
"always"
Examples of incorrect code for this rule with the default "always"
option:
/*eslint space-before-function-paren: "error"*/
/*eslint-env es6*/
function foo() {
// ...
}
var bar = function() {
// ...
};
var bar = function foo() {
// ...
};
class Foo {
constructor() {
// ...
}
}
var foo = {
bar() {
// ...
}
};
Examples of correct code for this rule with the default "always"
option:
/*eslint space-before-function-paren: "error"*/
/*eslint-env es6*/
function foo () {
// ...
}
var bar = function () {
// ...
};
var bar = function foo () {
// ...
};
class Foo {
constructor () {
// ...
}
}
var foo = {
bar () {
// ...
}
};
// async arrow function expressions are ignored by default.
var foo = async () => 1
var foo = async() => 1
"never"
Examples of incorrect code for this rule with the "never"
option:
/*eslint space-before-function-paren: ["error", "never"]*/
/*eslint-env es6*/
function foo () {
// ...
}
var bar = function () {
// ...
};
var bar = function foo () {
// ...
};
class Foo {
constructor () {
// ...
}
}
var foo = {
bar () {
// ...
}
};
Examples of correct code for this rule with the "never"
option:
/*eslint space-before-function-paren: ["error", "never"]*/
/*eslint-env es6*/
function foo() {
// ...
}
var bar = function() {
// ...
};
var bar = function foo() {
// ...
};
class Foo {
constructor() {
// ...
}
}
var foo = {
bar() {
// ...
}
};
// async arrow function expressions are ignored by default.
var foo = async () => 1
var foo = async() => 1
{"anonymous": "always", "named": "never", "asyncArrow": "always"}
Examples of incorrect code for this rule with the {"anonymous": "always", "named": "never", "asyncArrow": "always"}
option:
/*eslint space-before-function-paren: ["error", {"anonymous": "always", "named": "never", "asyncArrow": "always"}]*/
/*eslint-env es6*/
function foo () {
// ...
}
var bar = function() {
// ...
};
class Foo {
constructor () {
// ...
}
}
var foo = {
bar () {
// ...
}
};
var foo = async(a) => await a
Examples of correct code for this rule with the {"anonymous": "always", "named": "never", "asyncArrow": "always"}
option:
/*eslint space-before-function-paren: ["error", {"anonymous": "always", "named": "never", "asyncArrow": "always"}]*/
/*eslint-env es6*/
function foo() {
// ...
}
var bar = function () {
// ...
};
class Foo {
constructor() {
// ...
}
}
var foo = {
bar() {
// ...
}
};
var foo = async (a) => await a
{"anonymous": "never", "named": "always"}
Examples of incorrect code for this rule with the {"anonymous": "never", "named": "always"}
option:
/*eslint space-before-function-paren: ["error", { "anonymous": "never", "named": "always" }]*/
/*eslint-env es6*/
function foo() {
// ...
}
var bar = function () {
// ...
};
class Foo {
constructor() {
// ...
}
}
var foo = {
bar() {
// ...
}
};
Examples of correct code for this rule with the {"anonymous": "never", "named": "always"}
option:
/*eslint space-before-function-paren: ["error", { "anonymous": "never", "named": "always" }]*/
/*eslint-env es6*/
function foo () {
// ...
}
var bar = function() {
// ...
};
class Foo {
constructor () {
// ...
}
}
var foo = {
bar () {
// ...
}
};
{"anonymous": "ignore", "named": "always"}
Examples of incorrect code for this rule with the {"anonymous": "ignore", "named": "always"}
option:
/*eslint space-before-function-paren: ["error", { "anonymous": "ignore", "named": "always" }]*/
/*eslint-env es6*/
function foo() {
// ...
}
class Foo {
constructor() {
// ...
}
}
var foo = {
bar() {
// ...
}
};
Examples of correct code for this rule with the {"anonymous": "ignore", "named": "always"}
option:
/*eslint space-before-function-paren: ["error", { "anonymous": "ignore", "named": "always" }]*/
/*eslint-env es6*/
var bar = function() {
// ...
};
var bar = function () {
// ...
};
function foo () {
// ...
}
class Foo {
constructor () {
// ...
}
}
var foo = {
bar () {
// ...
}
};
When Not To Use It
You can turn this rule off if you are not concerned with the consistency of spacing before function parenthesis.
Related Rules
- [space-after-keywords](space-after-keywords.md)
- [space-return-throw-case](space-return-throw-case.md) Source: http://eslint.org/docs/rules/
Missing space before opening brace. Open
Label.prototype.hide = function(){
- Read upRead up
- Exclude checks
Require Or Disallow Space Before Blocks (space-before-blocks)
Consistency is an important part of any style guide. While it is a personal preference where to put the opening brace of blocks, it should be consistent across a whole project. Having an inconsistent style distracts the reader from seeing the important parts of the code.
Rule Details
This rule will enforce consistency of spacing before blocks. It is only applied on blocks that don’t begin on a new line.
- This rule ignores spacing which is between
=>
and a block. The spacing is handled by thearrow-spacing
rule. - This rule ignores spacing which is between a keyword and a block. The spacing is handled by the
keyword-spacing
rule.
Options
This rule takes one argument. If it is "always"
then blocks must always have at least one preceding space. If "never"
then all blocks should never have any preceding space. If different spacing is desired for function
blocks, keyword blocks and classes, an optional configuration object can be passed as the rule argument to
configure the cases separately.
( e.g. { "functions": "never", "keywords": "always", "classes": "always" }
)
The default is "always"
.
"always"
Examples of incorrect code for this rule with the "always" option:
/*eslint space-before-blocks: "error"*/
if (a){
b();
}
function a(){}
for (;;){
b();
}
try {} catch(a){}
class Foo{
constructor(){}
}
Examples of correct code for this rule with the "always" option:
/*eslint space-before-blocks: "error"*/
if (a) {
b();
}
if (a) {
b();
} else{ /*no error. this is checked by `keyword-spacing` rule.*/
c();
}
function a() {}
for (;;) {
b();
}
try {} catch(a) {}
"never"
Examples of incorrect code for this rule with the "never" option:
/*eslint space-before-blocks: ["error", "never"]*/
if (a) {
b();
}
function a() {}
for (;;) {
b();
}
try {} catch(a) {}
Examples of correct code for this rule with the "never" option:
/*eslint space-before-blocks: ["error", "never"]*/
if (a){
b();
}
function a(){}
for (;;){
b();
}
try{} catch(a){}
class Foo{
constructor(){}
}
Examples of incorrect code for this rule when configured { "functions": "never", "keywords": "always", "classes": "never" }
:
/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "always", "classes": "never" }]*/
/*eslint-env es6*/
function a() {}
try {} catch(a){}
class Foo{
constructor() {}
}
Examples of correct code for this rule when configured { "functions": "never", "keywords": "always", "classes": "never" }
:
/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "always", "classes": "never" }]*/
/*eslint-env es6*/
for (;;) {
// ...
}
describe(function(){
// ...
});
class Foo {
constructor(){}
}
Examples of incorrect code for this rule when configured { "functions": "always", "keywords": "never", "classes": "never" }
:
/*eslint space-before-blocks: ["error", { "functions": "always", "keywords": "never", "classes": "never" }]*/
/*eslint-env es6*/
function a(){}
try {} catch(a) {}
class Foo {
constructor(){}
}
Examples of correct code for this rule when configured { "functions": "always", "keywords": "never", "classes": "never" }
:
/*eslint space-before-blocks: ["error", { "functions": "always", "keywords": "never", "classes": "never" }]*/
/*eslint-env es6*/
if (a){
b();
}
var a = function() {}
class Foo{
constructor() {}
}
Examples of incorrect code for this rule when configured { "functions": "never", "keywords": "never", "classes": "always" }
:
/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "never", "classes": "always" }]*/
/*eslint-env es6*/
class Foo{
constructor(){}
}
Examples of correct code for this rule when configured { "functions": "never", "keywords": "never", "classes": "always" }
:
/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "never", "classes": "always" }]*/
/*eslint-env es6*/
class Foo {
constructor(){}
}
When Not To Use It
You can turn this rule off if you are not concerned with the consistency of spacing before blocks.
Related Rules
- [keyword-spacing](keyword-spacing.md)
- [arrow-spacing](arrow-spacing.md)
- [brace-style](brace-style.md) Source: http://eslint.org/docs/rules/
There should be no spaces inside this paren. Open
tinymce.DOM.setStyle( this.el, 'display', 'none' );
- Read upRead up
- Exclude checks
Disallow or enforce spaces inside of parentheses (space-in-parens)
Some style guides require or disallow spaces inside of parentheses:
foo( 'bar' );
var x = ( 1 + 2 ) * 3;
foo('bar');
var x = (1 + 2) * 3;
Rule Details
This rule will enforce consistency of spacing directly inside of parentheses, by disallowing or requiring one or more spaces to the right of (
and to the left of )
. In either case, ()
will still be allowed.
Options
There are two options for this rule:
-
"never"
(default) enforces zero spaces inside of parentheses -
"always"
enforces a space inside of parentheses
Depending on your coding conventions, you can choose either option by specifying it in your configuration:
"space-in-parens": ["error", "always"]
"never"
Examples of incorrect code for this rule with the default "never"
option:
/*eslint space-in-parens: ["error", "never"]*/
foo( 'bar');
foo('bar' );
foo( 'bar' );
var foo = ( 1 + 2 ) * 3;
( function () { return 'bar'; }() );
Examples of correct code for this rule with the default "never"
option:
/*eslint space-in-parens: ["error", "never"]*/
foo();
foo('bar');
var foo = (1 + 2) * 3;
(function () { return 'bar'; }());
"always"
Examples of incorrect code for this rule with the "always"
option:
/*eslint space-in-parens: ["error", "always"]*/
foo( 'bar');
foo('bar' );
foo('bar');
var foo = (1 + 2) * 3;
(function () { return 'bar'; }());
Examples of correct code for this rule with the "always"
option:
/*eslint space-in-parens: ["error", "always"]*/
foo();
foo( 'bar' );
var foo = ( 1 + 2 ) * 3;
( function () { return 'bar'; }() );
Exceptions
An object literal may be used as a third array item to specify exceptions, with the key "exceptions"
and an array as the value. These exceptions work in the context of the first option. That is, if "always"
is set to enforce spacing, then any "exception" will disallow spacing. Conversely, if "never"
is set to disallow spacing, then any "exception" will enforce spacing.
The following exceptions are available: ["{}", "[]", "()", "empty"]
.
Examples of incorrect code for this rule with the "never", { "exceptions": ["{}"] }
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["{}"] }]*/
foo({bar: 'baz'});
foo(1, {bar: 'baz'});
Examples of correct code for this rule with the "never", { "exceptions": ["{}"] }
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["{}"] }]*/
foo( {bar: 'baz'} );
foo(1, {bar: 'baz'} );
Examples of incorrect code for this rule with the "always", { "exceptions": ["{}"] }
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["{}"] }]*/
foo( {bar: 'baz'} );
foo( 1, {bar: 'baz'} );
Examples of correct code for this rule with the "always", { "exceptions": ["{}"] }
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["{}"] }]*/
foo({bar: 'baz'});
foo( 1, {bar: 'baz'});
Examples of incorrect code for this rule with the "never", { "exceptions": ["[]"] }
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["[]"] }]*/
foo([bar, baz]);
foo([bar, baz], 1);
Examples of correct code for this rule with the "never", { "exceptions": ["[]"] }
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["[]"] }]*/
foo( [bar, baz] );
foo( [bar, baz], 1);
Examples of incorrect code for this rule with the "always", { "exceptions": ["[]"] }
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["[]"] }]*/
foo( [bar, baz] );
foo( [bar, baz], 1 );
Examples of correct code for this rule with the "always", { "exceptions": ["[]"] }
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["[]"] }]*/
foo([bar, baz]);
foo([bar, baz], 1 );
Examples of incorrect code for this rule with the "never", { "exceptions": ["()"] }]
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["()"] }]*/
foo((1 + 2));
foo((1 + 2), 1);
Examples of correct code for this rule with the "never", { "exceptions": ["()"] }]
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["()"] }]*/
foo( (1 + 2) );
foo( (1 + 2), 1);
Examples of incorrect code for this rule with the "always", { "exceptions": ["()"] }]
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["()"] }]*/
foo( ( 1 + 2 ) );
foo( ( 1 + 2 ), 1 );
Examples of correct code for this rule with the "always", { "exceptions": ["()"] }]
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["()"] }]*/
foo(( 1 + 2 ));
foo(( 1 + 2 ), 1 );
The "empty"
exception concerns empty parentheses, and works the same way as the other exceptions, inverting the first option.
Example of incorrect code for this rule with the "never", { "exceptions": ["empty"] }]
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["empty"] }]*/
foo();
Example of correct code for this rule with the "never", { "exceptions": ["empty"] }]
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["empty"] }]*/
foo( );
Example of incorrect code for this rule with the "always", { "exceptions": ["empty"] }]
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["empty"] }]*/
foo( );
Example of correct code for this rule with the "always", { "exceptions": ["empty"] }]
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["empty"] }]*/
foo();
You can include multiple entries in the "exceptions"
array.
Examples of incorrect code for this rule with the "always", { "exceptions": ["{}", "[]"] }]
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["{}", "[]"] }]*/
bar( {bar:'baz'} );
baz( 1, [1,2] );
foo( {bar: 'baz'}, [1, 2] );
Examples of correct code for this rule with the "always", { "exceptions": ["{}", "[]"] }]
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["{}", "[]"] }]*/
bar({bar:'baz'});
baz( 1, [1,2]);
foo({bar: 'baz'}, [1, 2]);
When Not To Use It
You can turn this rule off if you are not concerned with the consistency of spacing between parentheses.
Related Rules
- [space-in-brackets](space-in-brackets.md) (deprecated) Source: http://eslint.org/docs/rules/
Expected indentation of 6 spaces but found 8. Open
function onKeydown(){
- Read upRead up
- Exclude checks
enforce consistent indentation (indent)
There are several common guidelines which require specific indentation of nested blocks and statements, like:
function hello(indentSize, type) {
if (indentSize === 4 && type !== 'tab') {
console.log('Each next indentation will increase on 4 spaces');
}
}
These are the most common scenarios recommended in different style guides:
- Two spaces, not longer and no tabs: Google, npm, Node.js, Idiomatic, Felix
- Tabs: jQuery
- Four spaces: Crockford
Rule Details
This rule enforces a consistent indentation style. The default style is 4 spaces
.
Options
This rule has a mixed option:
For example, for 2-space indentation:
{
"indent": ["error", 2]
}
Or for tabbed indentation:
{
"indent": ["error", "tab"]
}
Examples of incorrect code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
This rule has an object option:
-
"SwitchCase"
(default: 0) enforces indentation level forcase
clauses inswitch
statements -
"VariableDeclarator"
(default: 1) enforces indentation level forvar
declarators; can also take an object to define separate rules forvar
,let
andconst
declarations. -
"outerIIFEBody"
(default: 1) enforces indentation level for file-level IIFEs. -
"MemberExpression"
(off by default) enforces indentation level for multi-line property chains (except in variable declarations and assignments) -
"FunctionDeclaration"
takes an object to define rules for function declarations.-
parameters
(off by default) enforces indentation level for parameters in a function declaration. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the declaration must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function declaration.
-
-
"FunctionExpression"
takes an object to define rules for function expressions.-
parameters
(off by default) enforces indentation level for parameters in a function expression. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the expression must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function expression.
-
-
"CallExpression"
takes an object to define rules for function call expressions.-
arguments
(off by default) enforces indentation level for arguments in a call expression. This can either be a number indicating indentation level, or the string"first"
indicating that all arguments of the expression must be aligned with the first argument.
-
-
"ArrayExpression"
(default: 1) enforces indentation level for elements in arrays. It can also be set to the string"first"
, indicating that all the elements in the array should be aligned with the first element. -
"ObjectExpression"
(default: 1) enforces indentation level for properties in objects. It can be set to the string"first"
, indicating that all properties in the object should be aligned with the first property.
Level of indentation denotes the multiple of the indent specified. Example:
- Indent of 4 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 8 spaces. - Indent of 2 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 4 spaces. - Indent of 2 spaces with
VariableDeclarator
set to{"var": 2, "let": 2, "const": 3}
will indent the multi-line variable declarations with 4 spaces forvar
andlet
, 6 spaces forconst
statements. - Indent of tab with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 2 tabs. - Indent of 2 spaces with
SwitchCase
set to0
will not indentcase
clauses with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to1
will indentcase
clauses with 2 spaces with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to2
will indentcase
clauses with 4 spaces with respect toswitch
statements. - Indent of tab with
SwitchCase
set to2
will indentcase
clauses with 2 tabs with respect toswitch
statements. - Indent of 2 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 2 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 2 spaces. - Indent of 2 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 4 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 8 spaces.
tab
Examples of incorrect code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
/*tab*/b=c;
/*tab*/function foo(d) {
/*tab*//*tab*/e=f;
/*tab*/}
}
SwitchCase
Examples of incorrect code for this rule with the 2, { "SwitchCase": 1 }
options:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
Examples of correct code for this rule with the 2, { "SwitchCase": 1 }
option:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
VariableDeclarator
Examples of incorrect code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 2 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 2 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
outerIIFEBody
Examples of incorrect code for this rule with the options 2, { "outerIIFEBody": 0 }
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
Examples of correct code for this rule with the options 2, {"outerIIFEBody": 0}
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
MemberExpression
Examples of incorrect code for this rule with the 2, { "MemberExpression": 1 }
options:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz()
Examples of correct code for this rule with the 2, { "MemberExpression": 1 }
option:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz();
// Any indentation is permitted in variable declarations and assignments.
var bip = aardvark.badger
.coyote;
FunctionDeclaration
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
FunctionExpression
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
CallExpression
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
ArrayExpression
Examples of incorrect code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of incorrect code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
ObjectExpression
Examples of incorrect code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of correct code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of incorrect code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Examples of correct code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Compatibility
-
JSHint:
indent
- JSCS: validateIndentation Source: http://eslint.org/docs/rules/
All 'var' declarations must be at the top of the function scope. Open
var Label = function(){
- Read upRead up
- Exclude checks
Require Variable Declarations to be at the top of their scope (vars-on-top)
The vars-on-top
rule generates warnings when variable declarations are not used serially at the top of a function scope or the top of a program.
By default variable declarations are always moved (“hoisted”) invisibly to the top of their containing scope by the JavaScript interpreter.
This rule forces the programmer to represent that behaviour by manually moving the variable declaration to the top of its containing scope.
Rule Details
This rule aims to keep all variable declarations in the leading series of statements. Allowing multiple declarations helps promote maintainability and is thus allowed.
Examples of incorrect code for this rule:
/*eslint vars-on-top: "error"*/
// Variable declarations in a block:
function doSomething() {
var first;
if (true) {
first = true;
}
var second;
}
// Variable declaration in for initializer:
function doSomething() {
for (var i=0; i<10; i++) {}
}
/*eslint vars-on-top: "error"*/
// Variables after other statements:
f();
var a;
Examples of correct code for this rule:
/*eslint vars-on-top: "error"*/
function doSomething() {
var first;
var second; //multiple declarations are allowed at the top
if (true) {
first = true;
}
}
function doSomething() {
var i;
for (i=0; i<10; i++) {}
}
/*eslint vars-on-top: "error"*/
var a;
f();
/*eslint vars-on-top: "error"*/
// Directives may precede variable declarations.
"use strict";
var a;
f();
// Comments can describe variables.
function doSomething() {
// this is the first var.
var first;
// this is the second var.
var second
}
Further Reading
A space is required after '{'. Open
var placeholder_attrs = editor.settings.placeholder_attrs || {style: {position: 'absolute', top:'5px', left:0, color: '#888', padding: '1%', width:'98%', overflow: 'hidden', 'white-space': 'pre-wrap'} };
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- Exclude checks
enforce consistent spacing inside braces (object-curly-spacing)
While formatting preferences are very personal, a number of style guides require or disallow spaces between curly braces in the following situations:
// simple object literals
var obj = { foo: "bar" };
// nested object literals
var obj = { foo: { zoo: "bar" } };
// destructuring assignment (EcmaScript 6)
var { x, y } = y;
// import/export declarations (EcmaScript 6)
import { foo } from "bar";
export { foo };
Rule Details
This rule enforce consistent spacing inside braces of object literals, destructuring assignments, and import/export specifiers.
Options
This rule has two options, a string option and an object option.
String option:
-
"never"
(default) disallows spacing inside of braces -
"always"
requires spacing inside of braces (except{}
)
Object option:
-
"arraysInObjects": true
requires spacing inside of braces of objects beginning and/or ending with an array element (applies when the first option is set tonever
) -
"arraysInObjects": false
disallows spacing inside of braces of objects beginning and/or ending with an array element (applies when the first option is set toalways
) -
"objectsInObjects": true
requires spacing inside of braces of objects beginning and/or ending with an object element (applies when the first option is set tonever
) -
"objectsInObjects": false
disallows spacing inside of braces of objects beginning and/or ending with an object element (applies when the first option is set toalways
)
never
Examples of incorrect code for this rule with the default "never"
option:
/*eslint object-curly-spacing: ["error", "never"]*/
var obj = { 'foo': 'bar' };
var obj = {'foo': 'bar' };
var obj = { baz: {'foo': 'qux'}, bar};
var obj = {baz: { 'foo': 'qux'}, bar};
var {x } = y;
import { foo } from 'bar';
Examples of correct code for this rule with the default "never"
option:
/*eslint object-curly-spacing: ["error", "never"]*/
var obj = {'foo': 'bar'};
var obj = {'foo': {'bar': 'baz'}, 'qux': 'quxx'};
var obj = {
'foo': 'bar'
};
var obj = {'foo': 'bar'
};
var obj = {
'foo':'bar'};
var obj = {};
var {x} = y;
import {foo} from 'bar';
always
Examples of incorrect code for this rule with the "always"
option:
/*eslint object-curly-spacing: ["error", "always"]*/
var obj = {'foo': 'bar'};
var obj = {'foo': 'bar' };
var obj = { baz: {'foo': 'qux'}, bar};
var obj = {baz: { 'foo': 'qux' }, bar};
var obj = {'foo': 'bar'
};
var obj = {
'foo':'bar'};
var {x} = y;
import {foo } from 'bar';
Examples of correct code for this rule with the "always"
option:
/*eslint object-curly-spacing: ["error", "always"]*/
var obj = {};
var obj = { 'foo': 'bar' };
var obj = { 'foo': { 'bar': 'baz' }, 'qux': 'quxx' };
var obj = {
'foo': 'bar'
};
var { x } = y;
import { foo } from 'bar';
arraysInObjects
Examples of additional correct code for this rule with the "never", { "arraysInObjects": true }
options:
/*eslint object-curly-spacing: ["error", "never", { "arraysInObjects": true }]*/
var obj = {"foo": [ 1, 2 ] };
var obj = {"foo": [ "baz", "bar" ] };
Examples of additional correct code for this rule with the "always", { "arraysInObjects": false }
options:
/*eslint object-curly-spacing: ["error", "always", { "arraysInObjects": false }]*/
var obj = { "foo": [ 1, 2 ]};
var obj = { "foo": [ "baz", "bar" ]};
objectsInObjects
Examples of additional correct code for this rule with the "never", { "objectsInObjects": true }
options:
/*eslint object-curly-spacing: ["error", "never", { "objectsInObjects": true }]*/
var obj = {"foo": {"baz": 1, "bar": 2} };
Examples of additional correct code for this rule with the "always", { "objectsInObjects": false }
options:
/*eslint object-curly-spacing: ["error", "always", { "objectsInObjects": false }]*/
var obj = { "foo": { "baz": 1, "bar": 2 }};
When Not To Use It
You can turn this rule off if you are not concerned with the consistency of spacing between curly braces.
Related Rules
- [comma-spacing](comma-spacing.md)
- [space-in-parens](space-in-parens.md) Source: http://eslint.org/docs/rules/
Missing space before value for key 'top'. Open
var placeholder_attrs = editor.settings.placeholder_attrs || {style: {position: 'absolute', top:'5px', left:0, color: '#888', padding: '1%', width:'98%', overflow: 'hidden', 'white-space': 'pre-wrap'} };
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enforce consistent spacing between keys and values in object literal properties (key-spacing)
This rule enforces spacing around the colon in object literal properties. It can verify each property individually, or it can ensure horizontal alignment of adjacent properties in an object literal.
Rule Details
This rule enforces consistent spacing between keys and values in object literal properties. In the case of long lines, it is acceptable to add a new line wherever whitespace is allowed.
Options
This rule has an object option:
-
"beforeColon": false
(default) disallows spaces between the key and the colon in object literals. -
"beforeColon": true
requires at least one space between the key and the colon in object literals. -
"afterColon": true
(default) requires at least one space between the colon and the value in object literals. -
"afterColon": false
disallows spaces between the colon and the value in object literals. -
"mode": "strict"
(default) enforces exactly one space before or after colons in object literals. -
"mode": "minimum"
enforces one or more spaces before or after colons in object literals. -
"align": "value"
enforces horizontal alignment of values in object literals. -
"align": "colon"
enforces horizontal alignment of both colons and values in object literals. -
"align"
with an object value allows for fine-grained spacing when values are being aligned in object literals. -
"singleLine"
specifies a spacing style for single-line object literals. -
"multiLine"
specifies a spacing style for multi-line object literals.
Please note that you can either use the top-level options or the grouped options (singleLine
and multiLine
) but not both.
beforeColon
Examples of incorrect code for this rule with the default { "beforeColon": false }
option:
/*eslint key-spacing: ["error", { "beforeColon": false }]*/
var obj = { "foo" : 42 };
Examples of correct code for this rule with the default { "beforeColon": false }
option:
/*eslint key-spacing: ["error", { "beforeColon": false }]*/
var obj = { "foo": 42 };
Examples of incorrect code for this rule with the { "beforeColon": true }
option:
/*eslint key-spacing: ["error", { "beforeColon": true }]*/
var obj = { "foo": 42 };
Examples of correct code for this rule with the { "beforeColon": true }
option:
/*eslint key-spacing: ["error", { "beforeColon": true }]*/
var obj = { "foo" : 42 };
afterColon
Examples of incorrect code for this rule with the default { "afterColon": true }
option:
/*eslint key-spacing: ["error", { "afterColon": true }]*/
var obj = { "foo":42 };
Examples of correct code for this rule with the default { "afterColon": true }
option:
/*eslint key-spacing: ["error", { "afterColon": true }]*/
var obj = { "foo": 42 };
Examples of incorrect code for this rule with the { "afterColon": false }
option:
/*eslint key-spacing: ["error", { "afterColon": false }]*/
var obj = { "foo": 42 };
Examples of correct code for this rule with the { "afterColon": false }
option:
/*eslint key-spacing: ["error", { "afterColon": false }]*/
var obj = { "foo":42 };
mode
Examples of incorrect code for this rule with the default { "mode": "strict" }
option:
/*eslint key-spacing: ["error", { "mode": "strict" }]*/
call({
foobar: 42,
bat: 2 * 2
});
Examples of correct code for this rule with the default { "mode": "strict" }
option:
/*eslint key-spacing: ["error", { "mode": "strict" }]*/
call({
foobar: 42,
bat: 2 * 2
});
Examples of correct code for this rule with the { "mode": "minimum" }
option:
/*eslint key-spacing: ["error", { "mode": "minimum" }]*/
call({
foobar: 42,
bat: 2 * 2
});
align
Examples of incorrect code for this rule with the { "align": "value" }
option:
/*eslint key-spacing: ["error", { "align": "value" }]*/
var obj = {
a: value,
bcde: 42,
fg : foo()
};
Examples of correct code for this rule with the { "align": "value" }
option:
/*eslint key-spacing: ["error", { "align": "value" }]*/
var obj = {
a: value,
bcde: 42,
fg: foo(),
h: function() {
return this.a;
},
ijkl: 'Non-consecutive lines form a new group'
};
var obj = { a: "foo", longPropertyName: "bar" };
Examples of incorrect code for this rule with the { "align": "colon" }
option:
/*eslint key-spacing: ["error", { "align": "colon" }]*/
call({
foobar: 42,
bat: 2 * 2
});
Examples of correct code for this rule with the { "align": "colon" }
option:
/*eslint key-spacing: ["error", { "align": "colon" }]*/
call({
foobar: 42,
bat : 2 * 2
});
align
The align
option can take additional configuration through the beforeColon
, afterColon
, mode
, and on
options.
If align
is defined as an object, but not all of the parameters are provided, undefined parameters will default to the following:
// Defaults
align: {
"beforeColon": false,
"afterColon": true,
"on": "colon",
"mode": "strict"
}
Examples of correct code for this rule with sample { "align": { } }
options:
/*eslint key-spacing: ["error", {
"align": {
"beforeColon": true,
"afterColon": true,
"on": "colon"
}
}]*/
var obj = {
"one" : 1,
"seven" : 7
}
/*eslint key-spacing: ["error", {
"align": {
"beforeColon": false,
"afterColon": false,
"on": "value"
}
}]*/
var obj = {
"one": 1,
"seven":7
}
align and multiLine
The multiLine
and align
options can differ, which allows for fine-tuned control over the key-spacing
of your files. align
will not inherit from multiLine
if align
is configured as an object.
multiLine
is used any time an object literal spans multiple lines. The align
configuration is used when there is a group of properties in the same object. For example:
var myObj = {
key1: 1, // uses multiLine
key2: 2, // uses align (when defined)
key3: 3, // uses align (when defined)
key4: 4 // uses multiLine
}
Examples of incorrect code for this rule with sample { "align": { }, "multiLine": { } }
options:
/*eslint key-spacing: ["error", {
"multiLine": {
"beforeColon": false,
"afterColon":true
},
"align": {
"beforeColon": true,
"afterColon": true,
"on": "colon"
}
}]*/
var obj = {
"myObjectFunction": function() {
// Do something
},
"one" : 1,
"seven" : 7
}
Examples of correct code for this rule with sample { "align": { }, "multiLine": { } }
options:
/*eslint key-spacing: ["error", {
"multiLine": {
"beforeColon": false,
"afterColon": true
},
"align": {
"beforeColon": true,
"afterColon": true,
"on": "colon"
}
}]*/
var obj = {
"myObjectFunction": function() {
// Do something
//
}, // These are two separate groups, so no alignment between `myObjectFuction` and `one`
"one" : 1,
"seven" : 7 // `one` and `seven` are in their own group, and therefore aligned
}
singleLine and multiLine
Examples of correct code for this rule with sample { "singleLine": { }, "multiLine": { } }
options:
/*eslint "key-spacing": [2, {
"singleLine": {
"beforeColon": false,
"afterColon": true
},
"multiLine": {
"beforeColon": true,
"afterColon": true,
"align": "colon"
}
}]*/
var obj = { one: 1, "two": 2, three: 3 };
var obj2 = {
"two" : 2,
three : 3
};
When Not To Use It
If you have another convention for property spacing that might not be consistent with the available options, or if you want to permit multiple styles concurrently you can safely disable this rule. Source: http://eslint.org/docs/rules/
There should be no spaces inside this paren. Open
tinymce.DOM.setStyle( this.el, 'display', '' );
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Disallow or enforce spaces inside of parentheses (space-in-parens)
Some style guides require or disallow spaces inside of parentheses:
foo( 'bar' );
var x = ( 1 + 2 ) * 3;
foo('bar');
var x = (1 + 2) * 3;
Rule Details
This rule will enforce consistency of spacing directly inside of parentheses, by disallowing or requiring one or more spaces to the right of (
and to the left of )
. In either case, ()
will still be allowed.
Options
There are two options for this rule:
-
"never"
(default) enforces zero spaces inside of parentheses -
"always"
enforces a space inside of parentheses
Depending on your coding conventions, you can choose either option by specifying it in your configuration:
"space-in-parens": ["error", "always"]
"never"
Examples of incorrect code for this rule with the default "never"
option:
/*eslint space-in-parens: ["error", "never"]*/
foo( 'bar');
foo('bar' );
foo( 'bar' );
var foo = ( 1 + 2 ) * 3;
( function () { return 'bar'; }() );
Examples of correct code for this rule with the default "never"
option:
/*eslint space-in-parens: ["error", "never"]*/
foo();
foo('bar');
var foo = (1 + 2) * 3;
(function () { return 'bar'; }());
"always"
Examples of incorrect code for this rule with the "always"
option:
/*eslint space-in-parens: ["error", "always"]*/
foo( 'bar');
foo('bar' );
foo('bar');
var foo = (1 + 2) * 3;
(function () { return 'bar'; }());
Examples of correct code for this rule with the "always"
option:
/*eslint space-in-parens: ["error", "always"]*/
foo();
foo( 'bar' );
var foo = ( 1 + 2 ) * 3;
( function () { return 'bar'; }() );
Exceptions
An object literal may be used as a third array item to specify exceptions, with the key "exceptions"
and an array as the value. These exceptions work in the context of the first option. That is, if "always"
is set to enforce spacing, then any "exception" will disallow spacing. Conversely, if "never"
is set to disallow spacing, then any "exception" will enforce spacing.
The following exceptions are available: ["{}", "[]", "()", "empty"]
.
Examples of incorrect code for this rule with the "never", { "exceptions": ["{}"] }
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["{}"] }]*/
foo({bar: 'baz'});
foo(1, {bar: 'baz'});
Examples of correct code for this rule with the "never", { "exceptions": ["{}"] }
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["{}"] }]*/
foo( {bar: 'baz'} );
foo(1, {bar: 'baz'} );
Examples of incorrect code for this rule with the "always", { "exceptions": ["{}"] }
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["{}"] }]*/
foo( {bar: 'baz'} );
foo( 1, {bar: 'baz'} );
Examples of correct code for this rule with the "always", { "exceptions": ["{}"] }
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["{}"] }]*/
foo({bar: 'baz'});
foo( 1, {bar: 'baz'});
Examples of incorrect code for this rule with the "never", { "exceptions": ["[]"] }
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["[]"] }]*/
foo([bar, baz]);
foo([bar, baz], 1);
Examples of correct code for this rule with the "never", { "exceptions": ["[]"] }
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["[]"] }]*/
foo( [bar, baz] );
foo( [bar, baz], 1);
Examples of incorrect code for this rule with the "always", { "exceptions": ["[]"] }
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["[]"] }]*/
foo( [bar, baz] );
foo( [bar, baz], 1 );
Examples of correct code for this rule with the "always", { "exceptions": ["[]"] }
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["[]"] }]*/
foo([bar, baz]);
foo([bar, baz], 1 );
Examples of incorrect code for this rule with the "never", { "exceptions": ["()"] }]
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["()"] }]*/
foo((1 + 2));
foo((1 + 2), 1);
Examples of correct code for this rule with the "never", { "exceptions": ["()"] }]
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["()"] }]*/
foo( (1 + 2) );
foo( (1 + 2), 1);
Examples of incorrect code for this rule with the "always", { "exceptions": ["()"] }]
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["()"] }]*/
foo( ( 1 + 2 ) );
foo( ( 1 + 2 ), 1 );
Examples of correct code for this rule with the "always", { "exceptions": ["()"] }]
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["()"] }]*/
foo(( 1 + 2 ));
foo(( 1 + 2 ), 1 );
The "empty"
exception concerns empty parentheses, and works the same way as the other exceptions, inverting the first option.
Example of incorrect code for this rule with the "never", { "exceptions": ["empty"] }]
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["empty"] }]*/
foo();
Example of correct code for this rule with the "never", { "exceptions": ["empty"] }]
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["empty"] }]*/
foo( );
Example of incorrect code for this rule with the "always", { "exceptions": ["empty"] }]
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["empty"] }]*/
foo( );
Example of correct code for this rule with the "always", { "exceptions": ["empty"] }]
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["empty"] }]*/
foo();
You can include multiple entries in the "exceptions"
array.
Examples of incorrect code for this rule with the "always", { "exceptions": ["{}", "[]"] }]
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["{}", "[]"] }]*/
bar( {bar:'baz'} );
baz( 1, [1,2] );
foo( {bar: 'baz'}, [1, 2] );
Examples of correct code for this rule with the "always", { "exceptions": ["{}", "[]"] }]
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["{}", "[]"] }]*/
bar({bar:'baz'});
baz( 1, [1,2]);
foo({bar: 'baz'}, [1, 2]);
When Not To Use It
You can turn this rule off if you are not concerned with the consistency of spacing between parentheses.
Related Rules
- [space-in-brackets](space-in-brackets.md) (deprecated) Source: http://eslint.org/docs/rules/
Expected indentation of 6 spaces but found 8. Open
editor.on('focus', onFocus);
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- Exclude checks
enforce consistent indentation (indent)
There are several common guidelines which require specific indentation of nested blocks and statements, like:
function hello(indentSize, type) {
if (indentSize === 4 && type !== 'tab') {
console.log('Each next indentation will increase on 4 spaces');
}
}
These are the most common scenarios recommended in different style guides:
- Two spaces, not longer and no tabs: Google, npm, Node.js, Idiomatic, Felix
- Tabs: jQuery
- Four spaces: Crockford
Rule Details
This rule enforces a consistent indentation style. The default style is 4 spaces
.
Options
This rule has a mixed option:
For example, for 2-space indentation:
{
"indent": ["error", 2]
}
Or for tabbed indentation:
{
"indent": ["error", "tab"]
}
Examples of incorrect code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
This rule has an object option:
-
"SwitchCase"
(default: 0) enforces indentation level forcase
clauses inswitch
statements -
"VariableDeclarator"
(default: 1) enforces indentation level forvar
declarators; can also take an object to define separate rules forvar
,let
andconst
declarations. -
"outerIIFEBody"
(default: 1) enforces indentation level for file-level IIFEs. -
"MemberExpression"
(off by default) enforces indentation level for multi-line property chains (except in variable declarations and assignments) -
"FunctionDeclaration"
takes an object to define rules for function declarations.-
parameters
(off by default) enforces indentation level for parameters in a function declaration. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the declaration must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function declaration.
-
-
"FunctionExpression"
takes an object to define rules for function expressions.-
parameters
(off by default) enforces indentation level for parameters in a function expression. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the expression must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function expression.
-
-
"CallExpression"
takes an object to define rules for function call expressions.-
arguments
(off by default) enforces indentation level for arguments in a call expression. This can either be a number indicating indentation level, or the string"first"
indicating that all arguments of the expression must be aligned with the first argument.
-
-
"ArrayExpression"
(default: 1) enforces indentation level for elements in arrays. It can also be set to the string"first"
, indicating that all the elements in the array should be aligned with the first element. -
"ObjectExpression"
(default: 1) enforces indentation level for properties in objects. It can be set to the string"first"
, indicating that all properties in the object should be aligned with the first property.
Level of indentation denotes the multiple of the indent specified. Example:
- Indent of 4 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 8 spaces. - Indent of 2 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 4 spaces. - Indent of 2 spaces with
VariableDeclarator
set to{"var": 2, "let": 2, "const": 3}
will indent the multi-line variable declarations with 4 spaces forvar
andlet
, 6 spaces forconst
statements. - Indent of tab with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 2 tabs. - Indent of 2 spaces with
SwitchCase
set to0
will not indentcase
clauses with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to1
will indentcase
clauses with 2 spaces with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to2
will indentcase
clauses with 4 spaces with respect toswitch
statements. - Indent of tab with
SwitchCase
set to2
will indentcase
clauses with 2 tabs with respect toswitch
statements. - Indent of 2 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 2 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 2 spaces. - Indent of 2 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 4 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 8 spaces.
tab
Examples of incorrect code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
/*tab*/b=c;
/*tab*/function foo(d) {
/*tab*//*tab*/e=f;
/*tab*/}
}
SwitchCase
Examples of incorrect code for this rule with the 2, { "SwitchCase": 1 }
options:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
Examples of correct code for this rule with the 2, { "SwitchCase": 1 }
option:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
VariableDeclarator
Examples of incorrect code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 2 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 2 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
outerIIFEBody
Examples of incorrect code for this rule with the options 2, { "outerIIFEBody": 0 }
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
Examples of correct code for this rule with the options 2, {"outerIIFEBody": 0}
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
MemberExpression
Examples of incorrect code for this rule with the 2, { "MemberExpression": 1 }
options:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz()
Examples of correct code for this rule with the 2, { "MemberExpression": 1 }
option:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz();
// Any indentation is permitted in variable declarations and assignments.
var bip = aardvark.badger
.coyote;
FunctionDeclaration
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
FunctionExpression
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
CallExpression
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
ArrayExpression
Examples of incorrect code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of incorrect code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
ObjectExpression
Examples of incorrect code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of correct code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of incorrect code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Examples of correct code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Compatibility
-
JSHint:
indent
- JSCS: validateIndentation Source: http://eslint.org/docs/rules/
Expected indentation of 6 spaces but found 8. Open
function onBlur() {
- Read upRead up
- Exclude checks
enforce consistent indentation (indent)
There are several common guidelines which require specific indentation of nested blocks and statements, like:
function hello(indentSize, type) {
if (indentSize === 4 && type !== 'tab') {
console.log('Each next indentation will increase on 4 spaces');
}
}
These are the most common scenarios recommended in different style guides:
- Two spaces, not longer and no tabs: Google, npm, Node.js, Idiomatic, Felix
- Tabs: jQuery
- Four spaces: Crockford
Rule Details
This rule enforces a consistent indentation style. The default style is 4 spaces
.
Options
This rule has a mixed option:
For example, for 2-space indentation:
{
"indent": ["error", 2]
}
Or for tabbed indentation:
{
"indent": ["error", "tab"]
}
Examples of incorrect code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
This rule has an object option:
-
"SwitchCase"
(default: 0) enforces indentation level forcase
clauses inswitch
statements -
"VariableDeclarator"
(default: 1) enforces indentation level forvar
declarators; can also take an object to define separate rules forvar
,let
andconst
declarations. -
"outerIIFEBody"
(default: 1) enforces indentation level for file-level IIFEs. -
"MemberExpression"
(off by default) enforces indentation level for multi-line property chains (except in variable declarations and assignments) -
"FunctionDeclaration"
takes an object to define rules for function declarations.-
parameters
(off by default) enforces indentation level for parameters in a function declaration. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the declaration must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function declaration.
-
-
"FunctionExpression"
takes an object to define rules for function expressions.-
parameters
(off by default) enforces indentation level for parameters in a function expression. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the expression must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function expression.
-
-
"CallExpression"
takes an object to define rules for function call expressions.-
arguments
(off by default) enforces indentation level for arguments in a call expression. This can either be a number indicating indentation level, or the string"first"
indicating that all arguments of the expression must be aligned with the first argument.
-
-
"ArrayExpression"
(default: 1) enforces indentation level for elements in arrays. It can also be set to the string"first"
, indicating that all the elements in the array should be aligned with the first element. -
"ObjectExpression"
(default: 1) enforces indentation level for properties in objects. It can be set to the string"first"
, indicating that all properties in the object should be aligned with the first property.
Level of indentation denotes the multiple of the indent specified. Example:
- Indent of 4 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 8 spaces. - Indent of 2 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 4 spaces. - Indent of 2 spaces with
VariableDeclarator
set to{"var": 2, "let": 2, "const": 3}
will indent the multi-line variable declarations with 4 spaces forvar
andlet
, 6 spaces forconst
statements. - Indent of tab with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 2 tabs. - Indent of 2 spaces with
SwitchCase
set to0
will not indentcase
clauses with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to1
will indentcase
clauses with 2 spaces with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to2
will indentcase
clauses with 4 spaces with respect toswitch
statements. - Indent of tab with
SwitchCase
set to2
will indentcase
clauses with 2 tabs with respect toswitch
statements. - Indent of 2 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 2 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 2 spaces. - Indent of 2 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 4 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 8 spaces.
tab
Examples of incorrect code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
/*tab*/b=c;
/*tab*/function foo(d) {
/*tab*//*tab*/e=f;
/*tab*/}
}
SwitchCase
Examples of incorrect code for this rule with the 2, { "SwitchCase": 1 }
options:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
Examples of correct code for this rule with the 2, { "SwitchCase": 1 }
option:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
VariableDeclarator
Examples of incorrect code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 2 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 2 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
outerIIFEBody
Examples of incorrect code for this rule with the options 2, { "outerIIFEBody": 0 }
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
Examples of correct code for this rule with the options 2, {"outerIIFEBody": 0}
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
MemberExpression
Examples of incorrect code for this rule with the 2, { "MemberExpression": 1 }
options:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz()
Examples of correct code for this rule with the 2, { "MemberExpression": 1 }
option:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz();
// Any indentation is permitted in variable declarations and assignments.
var bip = aardvark.badger
.coyote;
FunctionDeclaration
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
FunctionExpression
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
CallExpression
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
ArrayExpression
Examples of incorrect code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of incorrect code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
ObjectExpression
Examples of incorrect code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of correct code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of incorrect code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Examples of correct code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Compatibility
-
JSHint:
indent
- JSCS: validateIndentation Source: http://eslint.org/docs/rules/
Expected indentation of 6 spaces but found 8. Open
tinymce.DOM.setStyle( this.el, 'display', 'none' );
- Read upRead up
- Exclude checks
enforce consistent indentation (indent)
There are several common guidelines which require specific indentation of nested blocks and statements, like:
function hello(indentSize, type) {
if (indentSize === 4 && type !== 'tab') {
console.log('Each next indentation will increase on 4 spaces');
}
}
These are the most common scenarios recommended in different style guides:
- Two spaces, not longer and no tabs: Google, npm, Node.js, Idiomatic, Felix
- Tabs: jQuery
- Four spaces: Crockford
Rule Details
This rule enforces a consistent indentation style. The default style is 4 spaces
.
Options
This rule has a mixed option:
For example, for 2-space indentation:
{
"indent": ["error", 2]
}
Or for tabbed indentation:
{
"indent": ["error", "tab"]
}
Examples of incorrect code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the default options:
/*eslint indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
This rule has an object option:
-
"SwitchCase"
(default: 0) enforces indentation level forcase
clauses inswitch
statements -
"VariableDeclarator"
(default: 1) enforces indentation level forvar
declarators; can also take an object to define separate rules forvar
,let
andconst
declarations. -
"outerIIFEBody"
(default: 1) enforces indentation level for file-level IIFEs. -
"MemberExpression"
(off by default) enforces indentation level for multi-line property chains (except in variable declarations and assignments) -
"FunctionDeclaration"
takes an object to define rules for function declarations.-
parameters
(off by default) enforces indentation level for parameters in a function declaration. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the declaration must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function declaration.
-
-
"FunctionExpression"
takes an object to define rules for function expressions.-
parameters
(off by default) enforces indentation level for parameters in a function expression. This can either be a number indicating indentation level, or the string"first"
indicating that all parameters of the expression must be aligned with the first parameter. -
body
(default: 1) enforces indentation level for the body of a function expression.
-
-
"CallExpression"
takes an object to define rules for function call expressions.-
arguments
(off by default) enforces indentation level for arguments in a call expression. This can either be a number indicating indentation level, or the string"first"
indicating that all arguments of the expression must be aligned with the first argument.
-
-
"ArrayExpression"
(default: 1) enforces indentation level for elements in arrays. It can also be set to the string"first"
, indicating that all the elements in the array should be aligned with the first element. -
"ObjectExpression"
(default: 1) enforces indentation level for properties in objects. It can be set to the string"first"
, indicating that all properties in the object should be aligned with the first property.
Level of indentation denotes the multiple of the indent specified. Example:
- Indent of 4 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 8 spaces. - Indent of 2 spaces with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 4 spaces. - Indent of 2 spaces with
VariableDeclarator
set to{"var": 2, "let": 2, "const": 3}
will indent the multi-line variable declarations with 4 spaces forvar
andlet
, 6 spaces forconst
statements. - Indent of tab with
VariableDeclarator
set to2
will indent the multi-line variable declarations with 2 tabs. - Indent of 2 spaces with
SwitchCase
set to0
will not indentcase
clauses with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to1
will indentcase
clauses with 2 spaces with respect toswitch
statements. - Indent of 2 spaces with
SwitchCase
set to2
will indentcase
clauses with 4 spaces with respect toswitch
statements. - Indent of tab with
SwitchCase
set to2
will indentcase
clauses with 2 tabs with respect toswitch
statements. - Indent of 2 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 2 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 2 spaces. - Indent of 2 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to0
will indent the multi-line property chains with 0 spaces. - Indent of 4 spaces with
MemberExpression
set to1
will indent the multi-line property chains with 4 spaces. - Indent of 4 spaces with
MemberExpression
set to2
will indent the multi-line property chains with 8 spaces.
tab
Examples of incorrect code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the "tab"
option:
/*eslint indent: ["error", "tab"]*/
if (a) {
/*tab*/b=c;
/*tab*/function foo(d) {
/*tab*//*tab*/e=f;
/*tab*/}
}
SwitchCase
Examples of incorrect code for this rule with the 2, { "SwitchCase": 1 }
options:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
Examples of correct code for this rule with the 2, { "SwitchCase": 1 }
option:
/*eslint indent: ["error", 2, { "SwitchCase": 1 }]*/
switch(a){
case "a":
break;
case "b":
break;
}
VariableDeclarator
Examples of incorrect code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 2 }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": 2 }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }
options:
/*eslint indent: ["error", 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }]*/
/*eslint-env es6*/
var a,
b,
c;
let a,
b,
c;
const a = 1,
b = 2,
c = 3;
outerIIFEBody
Examples of incorrect code for this rule with the options 2, { "outerIIFEBody": 0 }
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
Examples of correct code for this rule with the options 2, {"outerIIFEBody": 0}
:
/*eslint indent: ["error", 2, { "outerIIFEBody": 0 }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
if(y) {
console.log('foo');
}
MemberExpression
Examples of incorrect code for this rule with the 2, { "MemberExpression": 1 }
options:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz()
Examples of correct code for this rule with the 2, { "MemberExpression": 1 }
option:
/*eslint indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz();
// Any indentation is permitted in variable declarations and assignments.
var bip = aardvark.badger
.coyote;
FunctionDeclaration
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }]*/
function foo(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionDeclaration": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionDeclaration": {"parameters": "first"}}]*/
function foo(bar, baz,
qux, boop) {
qux();
}
FunctionExpression
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"body": 1, "parameters": 2} }
option:
/*eslint indent: ["error", 2, { "FunctionExpression": {"body": 1, "parameters": 2} }]*/
var foo = function(bar,
baz,
qux) {
qux();
}
Examples of incorrect code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
Examples of correct code for this rule with the 2, { "FunctionExpression": {"parameters": "first"} }
option:
/*eslint indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
CallExpression
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint indent: ["error", 2, { "CallExpression": {"arguments": 1} }]*/
foo(bar,
baz,
qux
);
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
Examples of correct code for this rule with the 2, { "CallExpression": {"arguments": "first"} }
option:
/*eslint indent: ["error", 2, {"CallExpression": {"arguments": "first"}}]*/
foo(bar, baz,
baz, boop, beep);
ArrayExpression
Examples of incorrect code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of incorrect code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
ObjectExpression
Examples of incorrect code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of correct code for this rule with the 2, { "ObjectExpression": 1 }
option:
/*eslint indent: ["error", 2, { "ObjectExpression": 1 }]*/
var foo = {
bar: 1,
baz: 2,
qux: 3
};
Examples of incorrect code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Examples of correct code for this rule with the 2, { "ObjectExpression": "first" }
option:
/*eslint indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
Compatibility
-
JSHint:
indent
- JSCS: validateIndentation Source: http://eslint.org/docs/rules/
Missing space before function parentheses. Open
Label.prototype.show = function(){
- Read upRead up
- Exclude checks
Require or disallow a space before function parenthesis (space-before-function-paren)
When formatting a function, whitespace is allowed between the function name or function
keyword and the opening paren. Named functions also require a space between the function
keyword and the function name, but anonymous functions require no whitespace. For example:
function withoutSpace(x) {
// ...
}
function withSpace (x) {
// ...
}
var anonymousWithoutSpace = function() {};
var anonymousWithSpace = function () {};
Style guides may require a space after the function
keyword for anonymous functions, while others specify no whitespace. Similarly, the space after a function name may or may not be required.
Rule Details
This rule aims to enforce consistent spacing before function parentheses and as such, will warn whenever whitespace doesn't match the preferences specified.
Options
This rule has a string option or an object option:
{
"space-before-function-paren": ["error", "always"],
// or
"space-before-function-paren": ["error", {
"anonymous": "always",
"named": "always",
"asyncArrow": "ignore"
}],
}
-
always
(default) requires a space followed by the(
of arguments. -
never
disallows any space followed by the(
of arguments.
The string option does not check async arrow function expressions for backward compatibility.
You can also use a separate option for each type of function.
Each of the following options can be set to "always"
, "never"
, or "ignore"
.
Default is "always"
basically.
-
anonymous
is for anonymous function expressions (e.g.function () {}
). -
named
is for named function expressions (e.g.function foo () {}
). -
asyncArrow
is for async arrow function expressions (e.g.async () => {}
).asyncArrow
is set to"ignore"
by default for backwards compatibility.
"always"
Examples of incorrect code for this rule with the default "always"
option:
/*eslint space-before-function-paren: "error"*/
/*eslint-env es6*/
function foo() {
// ...
}
var bar = function() {
// ...
};
var bar = function foo() {
// ...
};
class Foo {
constructor() {
// ...
}
}
var foo = {
bar() {
// ...
}
};
Examples of correct code for this rule with the default "always"
option:
/*eslint space-before-function-paren: "error"*/
/*eslint-env es6*/
function foo () {
// ...
}
var bar = function () {
// ...
};
var bar = function foo () {
// ...
};
class Foo {
constructor () {
// ...
}
}
var foo = {
bar () {
// ...
}
};
// async arrow function expressions are ignored by default.
var foo = async () => 1
var foo = async() => 1
"never"
Examples of incorrect code for this rule with the "never"
option:
/*eslint space-before-function-paren: ["error", "never"]*/
/*eslint-env es6*/
function foo () {
// ...
}
var bar = function () {
// ...
};
var bar = function foo () {
// ...
};
class Foo {
constructor () {
// ...
}
}
var foo = {
bar () {
// ...
}
};
Examples of correct code for this rule with the "never"
option:
/*eslint space-before-function-paren: ["error", "never"]*/
/*eslint-env es6*/
function foo() {
// ...
}
var bar = function() {
// ...
};
var bar = function foo() {
// ...
};
class Foo {
constructor() {
// ...
}
}
var foo = {
bar() {
// ...
}
};
// async arrow function expressions are ignored by default.
var foo = async () => 1
var foo = async() => 1
{"anonymous": "always", "named": "never", "asyncArrow": "always"}
Examples of incorrect code for this rule with the {"anonymous": "always", "named": "never", "asyncArrow": "always"}
option:
/*eslint space-before-function-paren: ["error", {"anonymous": "always", "named": "never", "asyncArrow": "always"}]*/
/*eslint-env es6*/
function foo () {
// ...
}
var bar = function() {
// ...
};
class Foo {
constructor () {
// ...
}
}
var foo = {
bar () {
// ...
}
};
var foo = async(a) => await a
Examples of correct code for this rule with the {"anonymous": "always", "named": "never", "asyncArrow": "always"}
option:
/*eslint space-before-function-paren: ["error", {"anonymous": "always", "named": "never", "asyncArrow": "always"}]*/
/*eslint-env es6*/
function foo() {
// ...
}
var bar = function () {
// ...
};
class Foo {
constructor() {
// ...
}
}
var foo = {
bar() {
// ...
}
};
var foo = async (a) => await a
{"anonymous": "never", "named": "always"}
Examples of incorrect code for this rule with the {"anonymous": "never", "named": "always"}
option:
/*eslint space-before-function-paren: ["error", { "anonymous": "never", "named": "always" }]*/
/*eslint-env es6*/
function foo() {
// ...
}
var bar = function () {
// ...
};
class Foo {
constructor() {
// ...
}
}
var foo = {
bar() {
// ...
}
};
Examples of correct code for this rule with the {"anonymous": "never", "named": "always"}
option:
/*eslint space-before-function-paren: ["error", { "anonymous": "never", "named": "always" }]*/
/*eslint-env es6*/
function foo () {
// ...
}
var bar = function() {
// ...
};
class Foo {
constructor () {
// ...
}
}
var foo = {
bar () {
// ...
}
};
{"anonymous": "ignore", "named": "always"}
Examples of incorrect code for this rule with the {"anonymous": "ignore", "named": "always"}
option:
/*eslint space-before-function-paren: ["error", { "anonymous": "ignore", "named": "always" }]*/
/*eslint-env es6*/
function foo() {
// ...
}
class Foo {
constructor() {
// ...
}
}
var foo = {
bar() {
// ...
}
};
Examples of correct code for this rule with the {"anonymous": "ignore", "named": "always"}
option:
/*eslint space-before-function-paren: ["error", { "anonymous": "ignore", "named": "always" }]*/
/*eslint-env es6*/
var bar = function() {
// ...
};
var bar = function () {
// ...
};
function foo () {
// ...
}
class Foo {
constructor () {
// ...
}
}
var foo = {
bar () {
// ...
}
};
When Not To Use It
You can turn this rule off if you are not concerned with the consistency of spacing before function parenthesis.
Related Rules
- [space-after-keywords](space-after-keywords.md)
- [space-return-throw-case](space-return-throw-case.md) Source: http://eslint.org/docs/rules/
There should be no spaces inside this paren. Open
tinymce.DOM.setStyle( this.el, 'display', '' );
- Read upRead up
- Exclude checks
Disallow or enforce spaces inside of parentheses (space-in-parens)
Some style guides require or disallow spaces inside of parentheses:
foo( 'bar' );
var x = ( 1 + 2 ) * 3;
foo('bar');
var x = (1 + 2) * 3;
Rule Details
This rule will enforce consistency of spacing directly inside of parentheses, by disallowing or requiring one or more spaces to the right of (
and to the left of )
. In either case, ()
will still be allowed.
Options
There are two options for this rule:
-
"never"
(default) enforces zero spaces inside of parentheses -
"always"
enforces a space inside of parentheses
Depending on your coding conventions, you can choose either option by specifying it in your configuration:
"space-in-parens": ["error", "always"]
"never"
Examples of incorrect code for this rule with the default "never"
option:
/*eslint space-in-parens: ["error", "never"]*/
foo( 'bar');
foo('bar' );
foo( 'bar' );
var foo = ( 1 + 2 ) * 3;
( function () { return 'bar'; }() );
Examples of correct code for this rule with the default "never"
option:
/*eslint space-in-parens: ["error", "never"]*/
foo();
foo('bar');
var foo = (1 + 2) * 3;
(function () { return 'bar'; }());
"always"
Examples of incorrect code for this rule with the "always"
option:
/*eslint space-in-parens: ["error", "always"]*/
foo( 'bar');
foo('bar' );
foo('bar');
var foo = (1 + 2) * 3;
(function () { return 'bar'; }());
Examples of correct code for this rule with the "always"
option:
/*eslint space-in-parens: ["error", "always"]*/
foo();
foo( 'bar' );
var foo = ( 1 + 2 ) * 3;
( function () { return 'bar'; }() );
Exceptions
An object literal may be used as a third array item to specify exceptions, with the key "exceptions"
and an array as the value. These exceptions work in the context of the first option. That is, if "always"
is set to enforce spacing, then any "exception" will disallow spacing. Conversely, if "never"
is set to disallow spacing, then any "exception" will enforce spacing.
The following exceptions are available: ["{}", "[]", "()", "empty"]
.
Examples of incorrect code for this rule with the "never", { "exceptions": ["{}"] }
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["{}"] }]*/
foo({bar: 'baz'});
foo(1, {bar: 'baz'});
Examples of correct code for this rule with the "never", { "exceptions": ["{}"] }
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["{}"] }]*/
foo( {bar: 'baz'} );
foo(1, {bar: 'baz'} );
Examples of incorrect code for this rule with the "always", { "exceptions": ["{}"] }
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["{}"] }]*/
foo( {bar: 'baz'} );
foo( 1, {bar: 'baz'} );
Examples of correct code for this rule with the "always", { "exceptions": ["{}"] }
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["{}"] }]*/
foo({bar: 'baz'});
foo( 1, {bar: 'baz'});
Examples of incorrect code for this rule with the "never", { "exceptions": ["[]"] }
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["[]"] }]*/
foo([bar, baz]);
foo([bar, baz], 1);
Examples of correct code for this rule with the "never", { "exceptions": ["[]"] }
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["[]"] }]*/
foo( [bar, baz] );
foo( [bar, baz], 1);
Examples of incorrect code for this rule with the "always", { "exceptions": ["[]"] }
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["[]"] }]*/
foo( [bar, baz] );
foo( [bar, baz], 1 );
Examples of correct code for this rule with the "always", { "exceptions": ["[]"] }
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["[]"] }]*/
foo([bar, baz]);
foo([bar, baz], 1 );
Examples of incorrect code for this rule with the "never", { "exceptions": ["()"] }]
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["()"] }]*/
foo((1 + 2));
foo((1 + 2), 1);
Examples of correct code for this rule with the "never", { "exceptions": ["()"] }]
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["()"] }]*/
foo( (1 + 2) );
foo( (1 + 2), 1);
Examples of incorrect code for this rule with the "always", { "exceptions": ["()"] }]
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["()"] }]*/
foo( ( 1 + 2 ) );
foo( ( 1 + 2 ), 1 );
Examples of correct code for this rule with the "always", { "exceptions": ["()"] }]
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["()"] }]*/
foo(( 1 + 2 ));
foo(( 1 + 2 ), 1 );
The "empty"
exception concerns empty parentheses, and works the same way as the other exceptions, inverting the first option.
Example of incorrect code for this rule with the "never", { "exceptions": ["empty"] }]
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["empty"] }]*/
foo();
Example of correct code for this rule with the "never", { "exceptions": ["empty"] }]
option:
/*eslint space-in-parens: ["error", "never", { "exceptions": ["empty"] }]*/
foo( );
Example of incorrect code for this rule with the "always", { "exceptions": ["empty"] }]
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["empty"] }]*/
foo( );
Example of correct code for this rule with the "always", { "exceptions": ["empty"] }]
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["empty"] }]*/
foo();
You can include multiple entries in the "exceptions"
array.
Examples of incorrect code for this rule with the "always", { "exceptions": ["{}", "[]"] }]
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["{}", "[]"] }]*/
bar( {bar:'baz'} );
baz( 1, [1,2] );
foo( {bar: 'baz'}, [1, 2] );
Examples of correct code for this rule with the "always", { "exceptions": ["{}", "[]"] }]
option:
/*eslint space-in-parens: ["error", "always", { "exceptions": ["{}", "[]"] }]*/
bar({bar:'baz'});
baz( 1, [1,2]);
foo({bar: 'baz'}, [1, 2]);
When Not To Use It
You can turn this rule off if you are not concerned with the consistency of spacing between parentheses.
Related Rules
- [space-in-brackets](space-in-brackets.md) (deprecated) Source: http://eslint.org/docs/rules/
Missing space before opening brace. Open
Label.prototype.show = function(){
- Read upRead up
- Exclude checks
Require Or Disallow Space Before Blocks (space-before-blocks)
Consistency is an important part of any style guide. While it is a personal preference where to put the opening brace of blocks, it should be consistent across a whole project. Having an inconsistent style distracts the reader from seeing the important parts of the code.
Rule Details
This rule will enforce consistency of spacing before blocks. It is only applied on blocks that don’t begin on a new line.
- This rule ignores spacing which is between
=>
and a block. The spacing is handled by thearrow-spacing
rule. - This rule ignores spacing which is between a keyword and a block. The spacing is handled by the
keyword-spacing
rule.
Options
This rule takes one argument. If it is "always"
then blocks must always have at least one preceding space. If "never"
then all blocks should never have any preceding space. If different spacing is desired for function
blocks, keyword blocks and classes, an optional configuration object can be passed as the rule argument to
configure the cases separately.
( e.g. { "functions": "never", "keywords": "always", "classes": "always" }
)
The default is "always"
.
"always"
Examples of incorrect code for this rule with the "always" option:
/*eslint space-before-blocks: "error"*/
if (a){
b();
}
function a(){}
for (;;){
b();
}
try {} catch(a){}
class Foo{
constructor(){}
}
Examples of correct code for this rule with the "always" option:
/*eslint space-before-blocks: "error"*/
if (a) {
b();
}
if (a) {
b();
} else{ /*no error. this is checked by `keyword-spacing` rule.*/
c();
}
function a() {}
for (;;) {
b();
}
try {} catch(a) {}
"never"
Examples of incorrect code for this rule with the "never" option:
/*eslint space-before-blocks: ["error", "never"]*/
if (a) {
b();
}
function a() {}
for (;;) {
b();
}
try {} catch(a) {}
Examples of correct code for this rule with the "never" option:
/*eslint space-before-blocks: ["error", "never"]*/
if (a){
b();
}
function a(){}
for (;;){
b();
}
try{} catch(a){}
class Foo{
constructor(){}
}
Examples of incorrect code for this rule when configured { "functions": "never", "keywords": "always", "classes": "never" }
:
/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "always", "classes": "never" }]*/
/*eslint-env es6*/
function a() {}
try {} catch(a){}
class Foo{
constructor() {}
}
Examples of correct code for this rule when configured { "functions": "never", "keywords": "always", "classes": "never" }
:
/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "always", "classes": "never" }]*/
/*eslint-env es6*/
for (;;) {
// ...
}
describe(function(){
// ...
});
class Foo {
constructor(){}
}
Examples of incorrect code for this rule when configured { "functions": "always", "keywords": "never", "classes": "never" }
:
/*eslint space-before-blocks: ["error", { "functions": "always", "keywords": "never", "classes": "never" }]*/
/*eslint-env es6*/
function a(){}
try {} catch(a) {}
class Foo {
constructor(){}
}
Examples of correct code for this rule when configured { "functions": "always", "keywords": "never", "classes": "never" }
:
/*eslint space-before-blocks: ["error", { "functions": "always", "keywords": "never", "classes": "never" }]*/
/*eslint-env es6*/
if (a){
b();
}
var a = function() {}
class Foo{
constructor() {}
}
Examples of incorrect code for this rule when configured { "functions": "never", "keywords": "never", "classes": "always" }
:
/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "never", "classes": "always" }]*/
/*eslint-env es6*/
class Foo{
constructor(){}
}
Examples of correct code for this rule when configured { "functions": "never", "keywords": "never", "classes": "always" }
:
/*eslint space-before-blocks: ["error", { "functions": "never", "keywords": "never", "classes": "always" }]*/
/*eslint-env es6*/
class Foo {
constructor(){}
}
When Not To Use It
You can turn this rule off if you are not concerned with the consistency of spacing before blocks.
Related Rules
- [keyword-spacing](keyword-spacing.md)
- [arrow-spacing](arrow-spacing.md)
- [brace-style](brace-style.md) Source: http://eslint.org/docs/rules/
Missing semicolon. Open
}
- Read upRead up
- Exclude checks
require or disallow semicolons instead of ASI (semi)
JavaScript is unique amongst the C-like languages in that it doesn't require semicolons at the end of each statement. In many cases, the JavaScript engine can determine that a semicolon should be in a certain spot and will automatically add it. This feature is known as automatic semicolon insertion (ASI) and is considered one of the more controversial features of JavaScript. For example, the following lines are both valid:
var name = "ESLint"
var website = "eslint.org";
On the first line, the JavaScript engine will automatically insert a semicolon, so this is not considered a syntax error. The JavaScript engine still knows how to interpret the line and knows that the line end indicates the end of the statement.
In the debate over ASI, there are generally two schools of thought. The first is that we should treat ASI as if it didn't exist and always include semicolons manually. The rationale is that it's easier to always include semicolons than to try to remember when they are or are not required, and thus decreases the possibility of introducing an error.
However, the ASI mechanism can sometimes be tricky to people who are using semicolons. For example, consider this code:
return
{
name: "ESLint"
};
This may look like a return
statement that returns an object literal, however, the JavaScript engine will interpret this code as:
return;
{
name: "ESLint";
}
Effectively, a semicolon is inserted after the return
statement, causing the code below it (a labeled literal inside a block) to be unreachable. This rule and the [no-unreachable](no-unreachable.md) rule will protect your code from such cases.
On the other side of the argument are those who says that since semicolons are inserted automatically, they are optional and do not need to be inserted manually. However, the ASI mechanism can also be tricky to people who don't use semicolons. For example, consider this code:
var globalCounter = { }
(function () {
var n = 0
globalCounter.increment = function () {
return ++n
}
})()
In this example, a semicolon will not be inserted after the first line, causing a run-time error (because an empty object is called as if it's a function). The [no-unexpected-multiline](no-unexpected-multiline.md) rule can protect your code from such cases.
Although ASI allows for more freedom over your coding style, it can also make your code behave in an unexpected way, whether you use semicolons or not. Therefore, it is best to know when ASI takes place and when it does not, and have ESLint protect your code from these potentially unexpected cases. In short, as once described by Isaac Schlueter, a \n
character always ends a statement (just like a semicolon) unless one of the following is true:
- The statement has an unclosed paren, array literal, or object literal or ends in some other way that is not a valid way to end a statement. (For instance, ending with
.
or,
.) - The line is
--
or++
(in which case it will decrement/increment the next token.) - It is a
for()
,while()
,do
,if()
, orelse
, and there is no{
- The next line starts with
[
,(
,+
,*
,/
,-
,,
,.
, or some other binary operator that can only be found between two tokens in a single expression.
Rule Details
This rule enforces consistent use of semicolons.
Options
This rule has two options, a string option and an object option.
String option:
-
"always"
(default) requires semicolons at the end of statements -
"never"
disallows semicolons as the end of statements (except to disambiguate statements beginning with[
,(
,/
,+
, or-
)
Object option:
-
"omitLastInOneLineBlock": true
ignores the last semicolon in a block in which its braces (and therefore the content of the block) are in the same line
always
Examples of incorrect code for this rule with the default "always"
option:
/*eslint semi: ["error", "always"]*/
var name = "ESLint"
object.method = function() {
// ...
}
Examples of correct code for this rule with the default "always"
option:
/*eslint semi: "error"*/
var name = "ESLint";
object.method = function() {
// ...
};
never
Examples of incorrect code for this rule with the "never"
option:
/*eslint semi: ["error", "never"]*/
var name = "ESLint";
object.method = function() {
// ...
};
Examples of correct code for this rule with the "never"
option:
/*eslint semi: ["error", "never"]*/
var name = "ESLint"
object.method = function() {
// ...
}
var name = "ESLint"
;(function() {
// ...
})()
omitLastInOneLineBlock
Examples of additional correct code for this rule with the "always", { "omitLastInOneLineBlock": true }
options:
/*eslint semi: ["error", "always", { "omitLastInOneLineBlock": true}] */
if (foo) { bar() }
if (foo) { bar(); baz() }
When Not To Use It
If you do not want to enforce semicolon usage (or omission) in any particular way, then you can turn this rule off.
Further Reading
Related Rules
- [no-extra-semi](no-extra-semi.md)
- [no-unexpected-multiline](no-unexpected-multiline.md)
- [semi-spacing](semi-spacing.md) Source: http://eslint.org/docs/rules/
'tinymce' is not defined. Open
this.el = tinymce.DOM.add( contentAreaContainer, editor.settings.placeholder_tag || "label", placeholder_attrs, placeholder_text );
- Read upRead up
- Exclude checks
Disallow Undeclared Variables (no-undef)
This rule can help you locate potential ReferenceErrors resulting from misspellings of variable and parameter names, or accidental implicit globals (for example, from forgetting the var
keyword in a for
loop initializer).
Rule Details
Any reference to an undeclared variable causes a warning, unless the variable is explicitly mentioned in a /*global ...*/
comment.
Examples of incorrect code for this rule:
/*eslint no-undef: "error"*/
var a = someFunction();
b = 10;
Examples of correct code for this rule with global
declaration:
/*global someFunction b:true*/
/*eslint no-undef: "error"*/
var a = someFunction();
b = 10;
The b:true
syntax in /*global */
indicates that assignment to b
is correct.
Examples of incorrect code for this rule with global
declaration:
/*global b*/
/*eslint no-undef: "error"*/
b = 10;
By default, variables declared in /*global */
are read-only, therefore assignment is incorrect.
Options
-
typeof
set to true will warn for variables used inside typeof check (Default false).
typeof
Examples of correct code for the default { "typeof": false }
option:
/*eslint no-undef: "error"*/
if (typeof UndefinedIdentifier === "undefined") {
// do something ...
}
You can use this option if you want to prevent typeof
check on a variable which has not been declared.
Examples of incorrect code for the { "typeof": true }
option:
/*eslint no-undef: ["error", { "typeof": true }] */
if(typeof a === "string"){}
Examples of correct code for the { "typeof": true }
option with global
declaration:
/*global a*/
/*eslint no-undef: ["error", { "typeof": true }] */
if(typeof a === "string"){}
Environments
For convenience, ESLint provides shortcuts that pre-define global variables exposed by popular libraries and runtime environments. This rule supports these environments, as listed in Specifying Environments. A few examples are given below.
browser
Examples of correct code for this rule with browser
environment:
/*eslint no-undef: "error"*/
/*eslint-env browser*/
setTimeout(function() {
alert("Hello");
});
node
Examples of correct code for this rule with node
environment:
/*eslint no-undef: "error"*/
/*eslint-env node*/
var fs = require("fs");
module.exports = function() {
console.log(fs);
};
When Not To Use It
If explicit declaration of global variables is not to your taste.
Compatibility
This rule provides compatibility with treatment of global variables in JSHint and JSLint. Source: http://eslint.org/docs/rules/
'tinymce' is not defined. Open
tinymce.DOM.setStyle( this.el, 'display', 'none' );
- Read upRead up
- Exclude checks
Disallow Undeclared Variables (no-undef)
This rule can help you locate potential ReferenceErrors resulting from misspellings of variable and parameter names, or accidental implicit globals (for example, from forgetting the var
keyword in a for
loop initializer).
Rule Details
Any reference to an undeclared variable causes a warning, unless the variable is explicitly mentioned in a /*global ...*/
comment.
Examples of incorrect code for this rule:
/*eslint no-undef: "error"*/
var a = someFunction();
b = 10;
Examples of correct code for this rule with global
declaration:
/*global someFunction b:true*/
/*eslint no-undef: "error"*/
var a = someFunction();
b = 10;
The b:true
syntax in /*global */
indicates that assignment to b
is correct.
Examples of incorrect code for this rule with global
declaration:
/*global b*/
/*eslint no-undef: "error"*/
b = 10;
By default, variables declared in /*global */
are read-only, therefore assignment is incorrect.
Options
-
typeof
set to true will warn for variables used inside typeof check (Default false).
typeof
Examples of correct code for the default { "typeof": false }
option:
/*eslint no-undef: "error"*/
if (typeof UndefinedIdentifier === "undefined") {
// do something ...
}
You can use this option if you want to prevent typeof
check on a variable which has not been declared.
Examples of incorrect code for the { "typeof": true }
option:
/*eslint no-undef: ["error", { "typeof": true }] */
if(typeof a === "string"){}
Examples of correct code for the { "typeof": true }
option with global
declaration:
/*global a*/
/*eslint no-undef: ["error", { "typeof": true }] */
if(typeof a === "string"){}
Environments
For convenience, ESLint provides shortcuts that pre-define global variables exposed by popular libraries and runtime environments. This rule supports these environments, as listed in Specifying Environments. A few examples are given below.
browser
Examples of correct code for this rule with browser
environment:
/*eslint no-undef: "error"*/
/*eslint-env browser*/
setTimeout(function() {
alert("Hello");
});
node
Examples of correct code for this rule with node
environment:
/*eslint no-undef: "error"*/
/*eslint-env node*/
var fs = require("fs");
module.exports = function() {
console.log(fs);
};
When Not To Use It
If explicit declaration of global variables is not to your taste.
Compatibility
This rule provides compatibility with treatment of global variables in JSHint and JSLint. Source: http://eslint.org/docs/rules/
'tinymce' is not defined. Open
tinymce.DOM.setStyle(contentAreaContainer, 'position', 'relative');
- Read upRead up
- Exclude checks
Disallow Undeclared Variables (no-undef)
This rule can help you locate potential ReferenceErrors resulting from misspellings of variable and parameter names, or accidental implicit globals (for example, from forgetting the var
keyword in a for
loop initializer).
Rule Details
Any reference to an undeclared variable causes a warning, unless the variable is explicitly mentioned in a /*global ...*/
comment.
Examples of incorrect code for this rule:
/*eslint no-undef: "error"*/
var a = someFunction();
b = 10;
Examples of correct code for this rule with global
declaration:
/*global someFunction b:true*/
/*eslint no-undef: "error"*/
var a = someFunction();
b = 10;
The b:true
syntax in /*global */
indicates that assignment to b
is correct.
Examples of incorrect code for this rule with global
declaration:
/*global b*/
/*eslint no-undef: "error"*/
b = 10;
By default, variables declared in /*global */
are read-only, therefore assignment is incorrect.
Options
-
typeof
set to true will warn for variables used inside typeof check (Default false).
typeof
Examples of correct code for the default { "typeof": false }
option:
/*eslint no-undef: "error"*/
if (typeof UndefinedIdentifier === "undefined") {
// do something ...
}
You can use this option if you want to prevent typeof
check on a variable which has not been declared.
Examples of incorrect code for the { "typeof": true }
option:
/*eslint no-undef: ["error", { "typeof": true }] */
if(typeof a === "string"){}
Examples of correct code for the { "typeof": true }
option with global
declaration:
/*global a*/
/*eslint no-undef: ["error", { "typeof": true }] */
if(typeof a === "string"){}
Environments
For convenience, ESLint provides shortcuts that pre-define global variables exposed by popular libraries and runtime environments. This rule supports these environments, as listed in Specifying Environments. A few examples are given below.
browser
Examples of correct code for this rule with browser
environment:
/*eslint no-undef: "error"*/
/*eslint-env browser*/
setTimeout(function() {
alert("Hello");
});
node
Examples of correct code for this rule with node
environment:
/*eslint no-undef: "error"*/
/*eslint-env node*/
var fs = require("fs");
module.exports = function() {
console.log(fs);
};
When Not To Use It
If explicit declaration of global variables is not to your taste.
Compatibility
This rule provides compatibility with treatment of global variables in JSHint and JSLint. Source: http://eslint.org/docs/rules/
'tinymce' is not defined. Open
tinymce.PluginManager.add('placeholder', function(editor) {
- Read upRead up
- Exclude checks
Disallow Undeclared Variables (no-undef)
This rule can help you locate potential ReferenceErrors resulting from misspellings of variable and parameter names, or accidental implicit globals (for example, from forgetting the var
keyword in a for
loop initializer).
Rule Details
Any reference to an undeclared variable causes a warning, unless the variable is explicitly mentioned in a /*global ...*/
comment.
Examples of incorrect code for this rule:
/*eslint no-undef: "error"*/
var a = someFunction();
b = 10;
Examples of correct code for this rule with global
declaration:
/*global someFunction b:true*/
/*eslint no-undef: "error"*/
var a = someFunction();
b = 10;
The b:true
syntax in /*global */
indicates that assignment to b
is correct.
Examples of incorrect code for this rule with global
declaration:
/*global b*/
/*eslint no-undef: "error"*/
b = 10;
By default, variables declared in /*global */
are read-only, therefore assignment is incorrect.
Options
-
typeof
set to true will warn for variables used inside typeof check (Default false).
typeof
Examples of correct code for the default { "typeof": false }
option:
/*eslint no-undef: "error"*/
if (typeof UndefinedIdentifier === "undefined") {
// do something ...
}
You can use this option if you want to prevent typeof
check on a variable which has not been declared.
Examples of incorrect code for the { "typeof": true }
option:
/*eslint no-undef: ["error", { "typeof": true }] */
if(typeof a === "string"){}
Examples of correct code for the { "typeof": true }
option with global
declaration:
/*global a*/
/*eslint no-undef: ["error", { "typeof": true }] */
if(typeof a === "string"){}
Environments
For convenience, ESLint provides shortcuts that pre-define global variables exposed by popular libraries and runtime environments. This rule supports these environments, as listed in Specifying Environments. A few examples are given below.
browser
Examples of correct code for this rule with browser
environment:
/*eslint no-undef: "error"*/
/*eslint-env browser*/
setTimeout(function() {
alert("Hello");
});
node
Examples of correct code for this rule with node
environment:
/*eslint no-undef: "error"*/
/*eslint-env node*/
var fs = require("fs");
module.exports = function() {
console.log(fs);
};
When Not To Use It
If explicit declaration of global variables is not to your taste.
Compatibility
This rule provides compatibility with treatment of global variables in JSHint and JSLint. Source: http://eslint.org/docs/rules/
'tinymce' is not defined. Open
tinymce.DOM.bind(label.el, 'click', onFocus);
- Read upRead up
- Exclude checks
Disallow Undeclared Variables (no-undef)
This rule can help you locate potential ReferenceErrors resulting from misspellings of variable and parameter names, or accidental implicit globals (for example, from forgetting the var
keyword in a for
loop initializer).
Rule Details
Any reference to an undeclared variable causes a warning, unless the variable is explicitly mentioned in a /*global ...*/
comment.
Examples of incorrect code for this rule:
/*eslint no-undef: "error"*/
var a = someFunction();
b = 10;
Examples of correct code for this rule with global
declaration:
/*global someFunction b:true*/
/*eslint no-undef: "error"*/
var a = someFunction();
b = 10;
The b:true
syntax in /*global */
indicates that assignment to b
is correct.
Examples of incorrect code for this rule with global
declaration:
/*global b*/
/*eslint no-undef: "error"*/
b = 10;
By default, variables declared in /*global */
are read-only, therefore assignment is incorrect.
Options
-
typeof
set to true will warn for variables used inside typeof check (Default false).
typeof
Examples of correct code for the default { "typeof": false }
option:
/*eslint no-undef: "error"*/
if (typeof UndefinedIdentifier === "undefined") {
// do something ...
}
You can use this option if you want to prevent typeof
check on a variable which has not been declared.
Examples of incorrect code for the { "typeof": true }
option:
/*eslint no-undef: ["error", { "typeof": true }] */
if(typeof a === "string"){}
Examples of correct code for the { "typeof": true }
option with global
declaration:
/*global a*/
/*eslint no-undef: ["error", { "typeof": true }] */
if(typeof a === "string"){}
Environments
For convenience, ESLint provides shortcuts that pre-define global variables exposed by popular libraries and runtime environments. This rule supports these environments, as listed in Specifying Environments. A few examples are given below.
browser
Examples of correct code for this rule with browser
environment:
/*eslint no-undef: "error"*/
/*eslint-env browser*/
setTimeout(function() {
alert("Hello");
});
node
Examples of correct code for this rule with node
environment:
/*eslint no-undef: "error"*/
/*eslint-env node*/
var fs = require("fs");
module.exports = function() {
console.log(fs);
};
When Not To Use It
If explicit declaration of global variables is not to your taste.
Compatibility
This rule provides compatibility with treatment of global variables in JSHint and JSLint. Source: http://eslint.org/docs/rules/
Expected '===' and instead saw '=='. Open
if (editor.getContent() == '') {
- Read upRead up
- Exclude checks
Require === and !== (eqeqeq)
It is considered good practice to use the type-safe equality operators ===
and !==
instead of their regular counterparts ==
and !=
.
The reason for this is that ==
and !=
do type coercion which follows the rather obscure Abstract Equality Comparison Algorithm.
For instance, the following statements are all considered true
:
[] == false
[] == ![]
3 == "03"
If one of those occurs in an innocent-looking statement such as a == b
the actual problem is very difficult to spot.
Rule Details
This rule is aimed at eliminating the type-unsafe equality operators.
Examples of incorrect code for this rule:
/*eslint eqeqeq: "error"*/
if (x == 42) { }
if ("" == text) { }
if (obj.getStuff() != undefined) { }
The --fix
option on the command line automatically fixes some problems reported by this rule. A problem is only fixed if one of the operands is a typeof
expression, or if both operands are literals with the same type.
Options
always
The "always"
option (default) enforces the use of ===
and !==
in every situation (except when you opt-in to more specific handling of null
[see below]).
Examples of incorrect code for the "always"
option:
/*eslint eqeqeq: ["error", "always"]*/
a == b
foo == true
bananas != 1
value == undefined
typeof foo == 'undefined'
'hello' != 'world'
0 == 0
true == true
foo == null
Examples of correct code for the "always"
option:
/*eslint eqeqeq: ["error", "always"]*/
a === b
foo === true
bananas !== 1
value === undefined
typeof foo === 'undefined'
'hello' !== 'world'
0 === 0
true === true
foo === null
This rule optionally takes a second argument, which should be an object with the following supported properties:
-
"null"
: Customize how this rule treatsnull
literals. Possible values:-
always
(default) - Always use === or !==. -
never
- Never use === or !== withnull
. -
ignore
- Do not apply this rule tonull
.
-
smart
The "smart"
option enforces the use of ===
and !==
except for these cases:
- Comparing two literal values
- Evaluating the value of
typeof
- Comparing against
null
Examples of incorrect code for the "smart"
option:
/*eslint eqeqeq: ["error", "smart"]*/
// comparing two variables requires ===
a == b
// only one side is a literal
foo == true
bananas != 1
// comparing to undefined requires ===
value == undefined
Examples of correct code for the "smart"
option:
/*eslint eqeqeq: ["error", "smart"]*/
typeof foo == 'undefined'
'hello' != 'world'
0 == 0
true == true
foo == null
allow-null
Deprecated: Instead of using this option use "always" and pass a "null" option property with value "ignore". This will tell eslint to always enforce strict equality except when comparing with the null
literal.
["error", "always", {"null": "ignore"}]
When Not To Use It
If you don't want to enforce a style for using equality operators, then it's safe to disable this rule. Source: http://eslint.org/docs/rules/
'tinymce' is not defined. Open
tinymce.DOM.setStyle( this.el, 'display', '' );
- Read upRead up
- Exclude checks
Disallow Undeclared Variables (no-undef)
This rule can help you locate potential ReferenceErrors resulting from misspellings of variable and parameter names, or accidental implicit globals (for example, from forgetting the var
keyword in a for
loop initializer).
Rule Details
Any reference to an undeclared variable causes a warning, unless the variable is explicitly mentioned in a /*global ...*/
comment.
Examples of incorrect code for this rule:
/*eslint no-undef: "error"*/
var a = someFunction();
b = 10;
Examples of correct code for this rule with global
declaration:
/*global someFunction b:true*/
/*eslint no-undef: "error"*/
var a = someFunction();
b = 10;
The b:true
syntax in /*global */
indicates that assignment to b
is correct.
Examples of incorrect code for this rule with global
declaration:
/*global b*/
/*eslint no-undef: "error"*/
b = 10;
By default, variables declared in /*global */
are read-only, therefore assignment is incorrect.
Options
-
typeof
set to true will warn for variables used inside typeof check (Default false).
typeof
Examples of correct code for the default { "typeof": false }
option:
/*eslint no-undef: "error"*/
if (typeof UndefinedIdentifier === "undefined") {
// do something ...
}
You can use this option if you want to prevent typeof
check on a variable which has not been declared.
Examples of incorrect code for the { "typeof": true }
option:
/*eslint no-undef: ["error", { "typeof": true }] */
if(typeof a === "string"){}
Examples of correct code for the { "typeof": true }
option with global
declaration:
/*global a*/
/*eslint no-undef: ["error", { "typeof": true }] */
if(typeof a === "string"){}
Environments
For convenience, ESLint provides shortcuts that pre-define global variables exposed by popular libraries and runtime environments. This rule supports these environments, as listed in Specifying Environments. A few examples are given below.
browser
Examples of correct code for this rule with browser
environment:
/*eslint no-undef: "error"*/
/*eslint-env browser*/
setTimeout(function() {
alert("Hello");
});
node
Examples of correct code for this rule with node
environment:
/*eslint no-undef: "error"*/
/*eslint-env node*/
var fs = require("fs");
module.exports = function() {
console.log(fs);
};
When Not To Use It
If explicit declaration of global variables is not to your taste.
Compatibility
This rule provides compatibility with treatment of global variables in JSHint and JSLint. Source: http://eslint.org/docs/rules/
'Label' was used before it was defined. Open
var label = new Label;
- Read upRead up
- Exclude checks
Disallow Early Use (no-use-before-define)
In JavaScript, prior to ES6, variable and function declarations are hoisted to the top of a scope, so it's possible to use identifiers before their formal declarations in code. This can be confusing and some believe it is best to always declare variables and functions before using them.
In ES6, block-level bindings (let
and const
) introduce a "temporal dead zone" where a ReferenceError
will be thrown with any attempt to access the variable before its declaration.
Rule Details
This rule will warn when it encounters a reference to an identifier that has not yet been declared.
Examples of incorrect code for this rule:
/*eslint no-use-before-define: "error"*/
/*eslint-env es6*/
alert(a);
var a = 10;
f();
function f() {}
function g() {
return b;
}
var b = 1;
// With blockBindings: true
{
alert(c);
let c = 1;
}
Examples of correct code for this rule:
/*eslint no-use-before-define: "error"*/
/*eslint-env es6*/
var a;
a = 10;
alert(a);
function f() {}
f(1);
var b = 1;
function g() {
return b;
}
// With blockBindings: true
{
let C;
c++;
}
Options
{
"no-use-before-define": ["error", { "functions": true, "classes": true }]
}
-
functions
(boolean
) - The flag which shows whether or not this rule checks function declarations. If this istrue
, this rule warns every reference to a function before the function declaration. Otherwise, ignores those references. Function declarations are hoisted, so it's safe. Default istrue
. -
classes
(boolean
) - The flag which shows whether or not this rule checks class declarations of upper scopes. If this istrue
, this rule warns every reference to a class before the class declaration. Otherwise, ignores those references if the declaration is in upper function scopes. Class declarations are not hoisted, so it might be danger. Default istrue
. -
variables
(boolean
) - This flag determines whether or not the rule checks variable declarations in upper scopes. If this istrue
, the rule warns every reference to a variable before the variable declaration. Otherwise, the rule ignores a reference if the declaration is in an upper scope, while still reporting the reference if it's in the same scope as the declaration. Default istrue
.
This rule accepts "nofunc"
string as an option.
"nofunc"
is the same as { "functions": false, "classes": true }
.
functions
Examples of correct code for the { "functions": false }
option:
/*eslint no-use-before-define: ["error", { "functions": false }]*/
f();
function f() {}
classes
Examples of incorrect code for the { "classes": false }
option:
/*eslint no-use-before-define: ["error", { "classes": false }]*/
/*eslint-env es6*/
new A();
class A {
}
Examples of correct code for the { "classes": false }
option:
/*eslint no-use-before-define: ["error", { "classes": false }]*/
/*eslint-env es6*/
function foo() {
return new A();
}
class A {
}
variables
Examples of incorrect code for the { "variables": false }
option:
/*eslint no-use-before-define: ["error", { "variables": false }]*/
console.log(foo);
var foo = 1;
Examples of correct code for the { "variables": false }
option:
/*eslint no-use-before-define: ["error", { "variables": false }]*/
function baz() {
console.log(foo);
}
var foo = 1;
Source: http://eslint.org/docs/rules/
'onFocus' was used before it was defined. Open
tinymce.DOM.bind(label.el, 'click', onFocus);
- Read upRead up
- Exclude checks
Disallow Early Use (no-use-before-define)
In JavaScript, prior to ES6, variable and function declarations are hoisted to the top of a scope, so it's possible to use identifiers before their formal declarations in code. This can be confusing and some believe it is best to always declare variables and functions before using them.
In ES6, block-level bindings (let
and const
) introduce a "temporal dead zone" where a ReferenceError
will be thrown with any attempt to access the variable before its declaration.
Rule Details
This rule will warn when it encounters a reference to an identifier that has not yet been declared.
Examples of incorrect code for this rule:
/*eslint no-use-before-define: "error"*/
/*eslint-env es6*/
alert(a);
var a = 10;
f();
function f() {}
function g() {
return b;
}
var b = 1;
// With blockBindings: true
{
alert(c);
let c = 1;
}
Examples of correct code for this rule:
/*eslint no-use-before-define: "error"*/
/*eslint-env es6*/
var a;
a = 10;
alert(a);
function f() {}
f(1);
var b = 1;
function g() {
return b;
}
// With blockBindings: true
{
let C;
c++;
}
Options
{
"no-use-before-define": ["error", { "functions": true, "classes": true }]
}
-
functions
(boolean
) - The flag which shows whether or not this rule checks function declarations. If this istrue
, this rule warns every reference to a function before the function declaration. Otherwise, ignores those references. Function declarations are hoisted, so it's safe. Default istrue
. -
classes
(boolean
) - The flag which shows whether or not this rule checks class declarations of upper scopes. If this istrue
, this rule warns every reference to a class before the class declaration. Otherwise, ignores those references if the declaration is in upper function scopes. Class declarations are not hoisted, so it might be danger. Default istrue
. -
variables
(boolean
) - This flag determines whether or not the rule checks variable declarations in upper scopes. If this istrue
, the rule warns every reference to a variable before the variable declaration. Otherwise, the rule ignores a reference if the declaration is in an upper scope, while still reporting the reference if it's in the same scope as the declaration. Default istrue
.
This rule accepts "nofunc"
string as an option.
"nofunc"
is the same as { "functions": false, "classes": true }
.
functions
Examples of correct code for the { "functions": false }
option:
/*eslint no-use-before-define: ["error", { "functions": false }]*/
f();
function f() {}
classes
Examples of incorrect code for the { "classes": false }
option:
/*eslint no-use-before-define: ["error", { "classes": false }]*/
/*eslint-env es6*/
new A();
class A {
}
Examples of correct code for the { "classes": false }
option:
/*eslint no-use-before-define: ["error", { "classes": false }]*/
/*eslint-env es6*/
function foo() {
return new A();
}
class A {
}
variables
Examples of incorrect code for the { "variables": false }
option:
/*eslint no-use-before-define: ["error", { "variables": false }]*/
console.log(foo);
var foo = 1;
Examples of correct code for the { "variables": false }
option:
/*eslint no-use-before-define: ["error", { "variables": false }]*/
function baz() {
console.log(foo);
}
var foo = 1;
Source: http://eslint.org/docs/rules/
'onBlur' was used before it was defined. Open
onBlur();
- Read upRead up
- Exclude checks
Disallow Early Use (no-use-before-define)
In JavaScript, prior to ES6, variable and function declarations are hoisted to the top of a scope, so it's possible to use identifiers before their formal declarations in code. This can be confusing and some believe it is best to always declare variables and functions before using them.
In ES6, block-level bindings (let
and const
) introduce a "temporal dead zone" where a ReferenceError
will be thrown with any attempt to access the variable before its declaration.
Rule Details
This rule will warn when it encounters a reference to an identifier that has not yet been declared.
Examples of incorrect code for this rule:
/*eslint no-use-before-define: "error"*/
/*eslint-env es6*/
alert(a);
var a = 10;
f();
function f() {}
function g() {
return b;
}
var b = 1;
// With blockBindings: true
{
alert(c);
let c = 1;
}
Examples of correct code for this rule:
/*eslint no-use-before-define: "error"*/
/*eslint-env es6*/
var a;
a = 10;
alert(a);
function f() {}
f(1);
var b = 1;
function g() {
return b;
}
// With blockBindings: true
{
let C;
c++;
}
Options
{
"no-use-before-define": ["error", { "functions": true, "classes": true }]
}
-
functions
(boolean
) - The flag which shows whether or not this rule checks function declarations. If this istrue
, this rule warns every reference to a function before the function declaration. Otherwise, ignores those references. Function declarations are hoisted, so it's safe. Default istrue
. -
classes
(boolean
) - The flag which shows whether or not this rule checks class declarations of upper scopes. If this istrue
, this rule warns every reference to a class before the class declaration. Otherwise, ignores those references if the declaration is in upper function scopes. Class declarations are not hoisted, so it might be danger. Default istrue
. -
variables
(boolean
) - This flag determines whether or not the rule checks variable declarations in upper scopes. If this istrue
, the rule warns every reference to a variable before the variable declaration. Otherwise, the rule ignores a reference if the declaration is in an upper scope, while still reporting the reference if it's in the same scope as the declaration. Default istrue
.
This rule accepts "nofunc"
string as an option.
"nofunc"
is the same as { "functions": false, "classes": true }
.
functions
Examples of correct code for the { "functions": false }
option:
/*eslint no-use-before-define: ["error", { "functions": false }]*/
f();
function f() {}
classes
Examples of incorrect code for the { "classes": false }
option:
/*eslint no-use-before-define: ["error", { "classes": false }]*/
/*eslint-env es6*/
new A();
class A {
}
Examples of correct code for the { "classes": false }
option:
/*eslint no-use-before-define: ["error", { "classes": false }]*/
/*eslint-env es6*/
function foo() {
return new A();
}
class A {
}
variables
Examples of incorrect code for the { "variables": false }
option:
/*eslint no-use-before-define: ["error", { "variables": false }]*/
console.log(foo);
var foo = 1;
Examples of correct code for the { "variables": false }
option:
/*eslint no-use-before-define: ["error", { "variables": false }]*/
function baz() {
console.log(foo);
}
var foo = 1;
Source: http://eslint.org/docs/rules/
'onBlur' was used before it was defined. Open
editor.on('change', onBlur);
- Read upRead up
- Exclude checks
Disallow Early Use (no-use-before-define)
In JavaScript, prior to ES6, variable and function declarations are hoisted to the top of a scope, so it's possible to use identifiers before their formal declarations in code. This can be confusing and some believe it is best to always declare variables and functions before using them.
In ES6, block-level bindings (let
and const
) introduce a "temporal dead zone" where a ReferenceError
will be thrown with any attempt to access the variable before its declaration.
Rule Details
This rule will warn when it encounters a reference to an identifier that has not yet been declared.
Examples of incorrect code for this rule:
/*eslint no-use-before-define: "error"*/
/*eslint-env es6*/
alert(a);
var a = 10;
f();
function f() {}
function g() {
return b;
}
var b = 1;
// With blockBindings: true
{
alert(c);
let c = 1;
}
Examples of correct code for this rule:
/*eslint no-use-before-define: "error"*/
/*eslint-env es6*/
var a;
a = 10;
alert(a);
function f() {}
f(1);
var b = 1;
function g() {
return b;
}
// With blockBindings: true
{
let C;
c++;
}
Options
{
"no-use-before-define": ["error", { "functions": true, "classes": true }]
}
-
functions
(boolean
) - The flag which shows whether or not this rule checks function declarations. If this istrue
, this rule warns every reference to a function before the function declaration. Otherwise, ignores those references. Function declarations are hoisted, so it's safe. Default istrue
. -
classes
(boolean
) - The flag which shows whether or not this rule checks class declarations of upper scopes. If this istrue
, this rule warns every reference to a class before the class declaration. Otherwise, ignores those references if the declaration is in upper function scopes. Class declarations are not hoisted, so it might be danger. Default istrue
. -
variables
(boolean
) - This flag determines whether or not the rule checks variable declarations in upper scopes. If this istrue
, the rule warns every reference to a variable before the variable declaration. Otherwise, the rule ignores a reference if the declaration is in an upper scope, while still reporting the reference if it's in the same scope as the declaration. Default istrue
.
This rule accepts "nofunc"
string as an option.
"nofunc"
is the same as { "functions": false, "classes": true }
.
functions
Examples of correct code for the { "functions": false }
option:
/*eslint no-use-before-define: ["error", { "functions": false }]*/
f();
function f() {}
classes
Examples of incorrect code for the { "classes": false }
option:
/*eslint no-use-before-define: ["error", { "classes": false }]*/
/*eslint-env es6*/
new A();
class A {
}
Examples of correct code for the { "classes": false }
option:
/*eslint no-use-before-define: ["error", { "classes": false }]*/
/*eslint-env es6*/
function foo() {
return new A();
}
class A {
}
variables
Examples of incorrect code for the { "variables": false }
option:
/*eslint no-use-before-define: ["error", { "variables": false }]*/
console.log(foo);
var foo = 1;
Examples of correct code for the { "variables": false }
option:
/*eslint no-use-before-define: ["error", { "variables": false }]*/
function baz() {
console.log(foo);
}
var foo = 1;
Source: http://eslint.org/docs/rules/
'onFocus' was used before it was defined. Open
editor.on('focus', onFocus);
- Read upRead up
- Exclude checks
Disallow Early Use (no-use-before-define)
In JavaScript, prior to ES6, variable and function declarations are hoisted to the top of a scope, so it's possible to use identifiers before their formal declarations in code. This can be confusing and some believe it is best to always declare variables and functions before using them.
In ES6, block-level bindings (let
and const
) introduce a "temporal dead zone" where a ReferenceError
will be thrown with any attempt to access the variable before its declaration.
Rule Details
This rule will warn when it encounters a reference to an identifier that has not yet been declared.
Examples of incorrect code for this rule:
/*eslint no-use-before-define: "error"*/
/*eslint-env es6*/
alert(a);
var a = 10;
f();
function f() {}
function g() {
return b;
}
var b = 1;
// With blockBindings: true
{
alert(c);
let c = 1;
}
Examples of correct code for this rule:
/*eslint no-use-before-define: "error"*/
/*eslint-env es6*/
var a;
a = 10;
alert(a);
function f() {}
f(1);
var b = 1;
function g() {
return b;
}
// With blockBindings: true
{
let C;
c++;
}
Options
{
"no-use-before-define": ["error", { "functions": true, "classes": true }]
}
-
functions
(boolean
) - The flag which shows whether or not this rule checks function declarations. If this istrue
, this rule warns every reference to a function before the function declaration. Otherwise, ignores those references. Function declarations are hoisted, so it's safe. Default istrue
. -
classes
(boolean
) - The flag which shows whether or not this rule checks class declarations of upper scopes. If this istrue
, this rule warns every reference to a class before the class declaration. Otherwise, ignores those references if the declaration is in upper function scopes. Class declarations are not hoisted, so it might be danger. Default istrue
. -
variables
(boolean
) - This flag determines whether or not the rule checks variable declarations in upper scopes. If this istrue
, the rule warns every reference to a variable before the variable declaration. Otherwise, the rule ignores a reference if the declaration is in an upper scope, while still reporting the reference if it's in the same scope as the declaration. Default istrue
.
This rule accepts "nofunc"
string as an option.
"nofunc"
is the same as { "functions": false, "classes": true }
.
functions
Examples of correct code for the { "functions": false }
option:
/*eslint no-use-before-define: ["error", { "functions": false }]*/
f();
function f() {}
classes
Examples of incorrect code for the { "classes": false }
option:
/*eslint no-use-before-define: ["error", { "classes": false }]*/
/*eslint-env es6*/
new A();
class A {
}
Examples of correct code for the { "classes": false }
option:
/*eslint no-use-before-define: ["error", { "classes": false }]*/
/*eslint-env es6*/
function foo() {
return new A();
}
class A {
}
variables
Examples of incorrect code for the { "variables": false }
option:
/*eslint no-use-before-define: ["error", { "variables": false }]*/
console.log(foo);
var foo = 1;
Examples of correct code for the { "variables": false }
option:
/*eslint no-use-before-define: ["error", { "variables": false }]*/
function baz() {
console.log(foo);
}
var foo = 1;
Source: http://eslint.org/docs/rules/
'onKeydown' was used before it was defined. Open
editor.on('keydown', onKeydown);
- Read upRead up
- Exclude checks
Disallow Early Use (no-use-before-define)
In JavaScript, prior to ES6, variable and function declarations are hoisted to the top of a scope, so it's possible to use identifiers before their formal declarations in code. This can be confusing and some believe it is best to always declare variables and functions before using them.
In ES6, block-level bindings (let
and const
) introduce a "temporal dead zone" where a ReferenceError
will be thrown with any attempt to access the variable before its declaration.
Rule Details
This rule will warn when it encounters a reference to an identifier that has not yet been declared.
Examples of incorrect code for this rule:
/*eslint no-use-before-define: "error"*/
/*eslint-env es6*/
alert(a);
var a = 10;
f();
function f() {}
function g() {
return b;
}
var b = 1;
// With blockBindings: true
{
alert(c);
let c = 1;
}
Examples of correct code for this rule:
/*eslint no-use-before-define: "error"*/
/*eslint-env es6*/
var a;
a = 10;
alert(a);
function f() {}
f(1);
var b = 1;
function g() {
return b;
}
// With blockBindings: true
{
let C;
c++;
}
Options
{
"no-use-before-define": ["error", { "functions": true, "classes": true }]
}
-
functions
(boolean
) - The flag which shows whether or not this rule checks function declarations. If this istrue
, this rule warns every reference to a function before the function declaration. Otherwise, ignores those references. Function declarations are hoisted, so it's safe. Default istrue
. -
classes
(boolean
) - The flag which shows whether or not this rule checks class declarations of upper scopes. If this istrue
, this rule warns every reference to a class before the class declaration. Otherwise, ignores those references if the declaration is in upper function scopes. Class declarations are not hoisted, so it might be danger. Default istrue
. -
variables
(boolean
) - This flag determines whether or not the rule checks variable declarations in upper scopes. If this istrue
, the rule warns every reference to a variable before the variable declaration. Otherwise, the rule ignores a reference if the declaration is in an upper scope, while still reporting the reference if it's in the same scope as the declaration. Default istrue
.
This rule accepts "nofunc"
string as an option.
"nofunc"
is the same as { "functions": false, "classes": true }
.
functions
Examples of correct code for the { "functions": false }
option:
/*eslint no-use-before-define: ["error", { "functions": false }]*/
f();
function f() {}
classes
Examples of incorrect code for the { "classes": false }
option:
/*eslint no-use-before-define: ["error", { "classes": false }]*/
/*eslint-env es6*/
new A();
class A {
}
Examples of correct code for the { "classes": false }
option:
/*eslint no-use-before-define: ["error", { "classes": false }]*/
/*eslint-env es6*/
function foo() {
return new A();
}
class A {
}
variables
Examples of incorrect code for the { "variables": false }
option:
/*eslint no-use-before-define: ["error", { "variables": false }]*/
console.log(foo);
var foo = 1;
Examples of correct code for the { "variables": false }
option:
/*eslint no-use-before-define: ["error", { "variables": false }]*/
function baz() {
console.log(foo);
}
var foo = 1;
Source: http://eslint.org/docs/rules/
'onBlur' was used before it was defined. Open
editor.on('blur', onBlur);
- Read upRead up
- Exclude checks
Disallow Early Use (no-use-before-define)
In JavaScript, prior to ES6, variable and function declarations are hoisted to the top of a scope, so it's possible to use identifiers before their formal declarations in code. This can be confusing and some believe it is best to always declare variables and functions before using them.
In ES6, block-level bindings (let
and const
) introduce a "temporal dead zone" where a ReferenceError
will be thrown with any attempt to access the variable before its declaration.
Rule Details
This rule will warn when it encounters a reference to an identifier that has not yet been declared.
Examples of incorrect code for this rule:
/*eslint no-use-before-define: "error"*/
/*eslint-env es6*/
alert(a);
var a = 10;
f();
function f() {}
function g() {
return b;
}
var b = 1;
// With blockBindings: true
{
alert(c);
let c = 1;
}
Examples of correct code for this rule:
/*eslint no-use-before-define: "error"*/
/*eslint-env es6*/
var a;
a = 10;
alert(a);
function f() {}
f(1);
var b = 1;
function g() {
return b;
}
// With blockBindings: true
{
let C;
c++;
}
Options
{
"no-use-before-define": ["error", { "functions": true, "classes": true }]
}
-
functions
(boolean
) - The flag which shows whether or not this rule checks function declarations. If this istrue
, this rule warns every reference to a function before the function declaration. Otherwise, ignores those references. Function declarations are hoisted, so it's safe. Default istrue
. -
classes
(boolean
) - The flag which shows whether or not this rule checks class declarations of upper scopes. If this istrue
, this rule warns every reference to a class before the class declaration. Otherwise, ignores those references if the declaration is in upper function scopes. Class declarations are not hoisted, so it might be danger. Default istrue
. -
variables
(boolean
) - This flag determines whether or not the rule checks variable declarations in upper scopes. If this istrue
, the rule warns every reference to a variable before the variable declaration. Otherwise, the rule ignores a reference if the declaration is in an upper scope, while still reporting the reference if it's in the same scope as the declaration. Default istrue
.
This rule accepts "nofunc"
string as an option.
"nofunc"
is the same as { "functions": false, "classes": true }
.
functions
Examples of correct code for the { "functions": false }
option:
/*eslint no-use-before-define: ["error", { "functions": false }]*/
f();
function f() {}
classes
Examples of incorrect code for the { "classes": false }
option:
/*eslint no-use-before-define: ["error", { "classes": false }]*/
/*eslint-env es6*/
new A();
class A {
}
Examples of correct code for the { "classes": false }
option:
/*eslint no-use-before-define: ["error", { "classes": false }]*/
/*eslint-env es6*/
function foo() {
return new A();
}
class A {
}
variables
Examples of incorrect code for the { "variables": false }
option:
/*eslint no-use-before-define: ["error", { "variables": false }]*/
console.log(foo);
var foo = 1;
Examples of correct code for the { "variables": false }
option:
/*eslint no-use-before-define: ["error", { "variables": false }]*/
function baz() {
console.log(foo);
}
var foo = 1;
Source: http://eslint.org/docs/rules/
'onBlur' was used before it was defined. Open
editor.on('setContent', onBlur);
- Read upRead up
- Exclude checks
Disallow Early Use (no-use-before-define)
In JavaScript, prior to ES6, variable and function declarations are hoisted to the top of a scope, so it's possible to use identifiers before their formal declarations in code. This can be confusing and some believe it is best to always declare variables and functions before using them.
In ES6, block-level bindings (let
and const
) introduce a "temporal dead zone" where a ReferenceError
will be thrown with any attempt to access the variable before its declaration.
Rule Details
This rule will warn when it encounters a reference to an identifier that has not yet been declared.
Examples of incorrect code for this rule:
/*eslint no-use-before-define: "error"*/
/*eslint-env es6*/
alert(a);
var a = 10;
f();
function f() {}
function g() {
return b;
}
var b = 1;
// With blockBindings: true
{
alert(c);
let c = 1;
}
Examples of correct code for this rule:
/*eslint no-use-before-define: "error"*/
/*eslint-env es6*/
var a;
a = 10;
alert(a);
function f() {}
f(1);
var b = 1;
function g() {
return b;
}
// With blockBindings: true
{
let C;
c++;
}
Options
{
"no-use-before-define": ["error", { "functions": true, "classes": true }]
}
-
functions
(boolean
) - The flag which shows whether or not this rule checks function declarations. If this istrue
, this rule warns every reference to a function before the function declaration. Otherwise, ignores those references. Function declarations are hoisted, so it's safe. Default istrue
. -
classes
(boolean
) - The flag which shows whether or not this rule checks class declarations of upper scopes. If this istrue
, this rule warns every reference to a class before the class declaration. Otherwise, ignores those references if the declaration is in upper function scopes. Class declarations are not hoisted, so it might be danger. Default istrue
. -
variables
(boolean
) - This flag determines whether or not the rule checks variable declarations in upper scopes. If this istrue
, the rule warns every reference to a variable before the variable declaration. Otherwise, the rule ignores a reference if the declaration is in an upper scope, while still reporting the reference if it's in the same scope as the declaration. Default istrue
.
This rule accepts "nofunc"
string as an option.
"nofunc"
is the same as { "functions": false, "classes": true }
.
functions
Examples of correct code for the { "functions": false }
option:
/*eslint no-use-before-define: ["error", { "functions": false }]*/
f();
function f() {}
classes
Examples of incorrect code for the { "classes": false }
option:
/*eslint no-use-before-define: ["error", { "classes": false }]*/
/*eslint-env es6*/
new A();
class A {
}
Examples of correct code for the { "classes": false }
option:
/*eslint no-use-before-define: ["error", { "classes": false }]*/
/*eslint-env es6*/
function foo() {
return new A();
}
class A {
}
variables
Examples of incorrect code for the { "variables": false }
option:
/*eslint no-use-before-define: ["error", { "variables": false }]*/
console.log(foo);
var foo = 1;
Examples of correct code for the { "variables": false }
option:
/*eslint no-use-before-define: ["error", { "variables": false }]*/
function baz() {
console.log(foo);
}
var foo = 1;
Source: http://eslint.org/docs/rules/