Showing 296 of 296 total issues
Missing trailing comma. Open
/^(0|20|40|60|80|100)$/i
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require or disallow trailing commas (comma-dangle)
Trailing commas in object literals are valid according to the ECMAScript 5 (and ECMAScript 3!) spec. However, IE8 (when not in IE8 document mode) and below will throw an error when it encounters trailing commas in JavaScript.
var foo = {
bar: "baz",
qux: "quux",
};
Trailing commas simplify adding and removing items to objects and arrays, since only the lines you are modifying must be touched. Another argument in favor of trailing commas is that it improves the clarity of diffs when an item is added or removed from an object or array:
Less clear:
var foo = {
- bar: "baz",
- qux: "quux"
+ bar: "baz"
};
More clear:
var foo = {
bar: "baz",
- qux: "quux",
};
Rule Details
This rule enforces consistent use of trailing commas in object and array literals.
Options
This rule has a string option or an object option:
{
"comma-dangle": ["error", "never"],
// or
"comma-dangle": ["error", {
"arrays": "never",
"objects": "never",
"imports": "never",
"exports": "never",
"functions": "ignore",
}]
}
-
"never"
(default) disallows trailing commas -
"always"
requires trailing commas -
"always-multiline"
requires trailing commas when the last element or property is in a different line than the closing]
or}
and disallows trailing commas when the last element or property is on the same line as the closing]
or}
-
"only-multiline"
allows (but does not require) trailing commas when the last element or property is in a different line than the closing]
or}
and disallows trailing commas when the last element or property is on the same line as the closing]
or}
Trailing commas in function declarations and function calls are valid syntax since ECMAScript 2017; however, the string option does not check these situations for backwards compatibility.
You can also use an object option to configure this rule for each type of syntax.
Each of the following options can be set to "never"
, "always"
, "always-multiline"
, "only-multiline"
, or "ignore"
.
The default for each option is "never"
unless otherwise specified.
-
arrays
is for array literals and array patterns of destructuring. (e.g.let [a,] = [1,];
) -
objects
is for object literals and object patterns of destructuring. (e.g.let {a,} = {a: 1};
) -
imports
is for import declarations of ES Modules. (e.g.import {a,} from "foo";
) -
exports
is for export declarations of ES Modules. (e.g.export {a,};
) -
functions
is for function declarations and function calls. (e.g.(function(a,){ })(b,);
)
functions
is set to"ignore"
by default for consistency with the string option.
never
Examples of incorrect code for this rule with the default "never"
option:
/*eslint comma-dangle: ["error", "never"]*/
var foo = {
bar: "baz",
qux: "quux",
};
var arr = [1,2,];
foo({
bar: "baz",
qux: "quux",
});
Examples of correct code for this rule with the default "never"
option:
/*eslint comma-dangle: ["error", "never"]*/
var foo = {
bar: "baz",
qux: "quux"
};
var arr = [1,2];
foo({
bar: "baz",
qux: "quux"
});
always
Examples of incorrect code for this rule with the "always"
option:
/*eslint comma-dangle: ["error", "always"]*/
var foo = {
bar: "baz",
qux: "quux"
};
var arr = [1,2];
foo({
bar: "baz",
qux: "quux"
});
Examples of correct code for this rule with the "always"
option:
/*eslint comma-dangle: ["error", "always"]*/
var foo = {
bar: "baz",
qux: "quux",
};
var arr = [1,2,];
foo({
bar: "baz",
qux: "quux",
});
always-multiline
Examples of incorrect code for this rule with the "always-multiline"
option:
/*eslint comma-dangle: ["error", "always-multiline"]*/
var foo = {
bar: "baz",
qux: "quux"
};
var foo = { bar: "baz", qux: "quux", };
var arr = [1,2,];
var arr = [1,
2,];
var arr = [
1,
2
];
foo({
bar: "baz",
qux: "quux"
});
Examples of correct code for this rule with the "always-multiline"
option:
/*eslint comma-dangle: ["error", "always-multiline"]*/
var foo = {
bar: "baz",
qux: "quux",
};
var foo = {bar: "baz", qux: "quux"};
var arr = [1,2];
var arr = [1,
2];
var arr = [
1,
2,
];
foo({
bar: "baz",
qux: "quux",
});
only-multiline
Examples of incorrect code for this rule with the "only-multiline"
option:
/*eslint comma-dangle: ["error", "only-multiline"]*/
var foo = { bar: "baz", qux: "quux", };
var arr = [1,2,];
var arr = [1,
2,];
Examples of correct code for this rule with the "only-multiline"
option:
/*eslint comma-dangle: ["error", "only-multiline"]*/
var foo = {
bar: "baz",
qux: "quux",
};
var foo = {
bar: "baz",
qux: "quux"
};
var foo = {bar: "baz", qux: "quux"};
var arr = [1,2];
var arr = [1,
2];
var arr = [
1,
2,
];
var arr = [
1,
2
];
foo({
bar: "baz",
qux: "quux",
});
foo({
bar: "baz",
qux: "quux"
});
functions
Examples of incorrect code for this rule with the {"functions": "never"}
option:
/*eslint comma-dangle: ["error", {"functions": "never"}]*/
function foo(a, b,) {
}
foo(a, b,);
new foo(a, b,);
Examples of correct code for this rule with the {"functions": "never"}
option:
/*eslint comma-dangle: ["error", {"functions": "never"}]*/
function foo(a, b) {
}
foo(a, b);
new foo(a, b);
Examples of incorrect code for this rule with the {"functions": "always"}
option:
/*eslint comma-dangle: ["error", {"functions": "always"}]*/
function foo(a, b) {
}
foo(a, b);
new foo(a, b);
Examples of correct code for this rule with the {"functions": "always"}
option:
/*eslint comma-dangle: ["error", {"functions": "always"}]*/
function foo(a, b,) {
}
foo(a, b,);
new foo(a, b,);
When Not To Use It
You can turn this rule off if you are not concerned with dangling commas. Source: http://eslint.org/docs/rules/
Expected line break before .option
. Open
).option(
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- Exclude checks
require a newline after each call in a method chain (newline-per-chained-call)
Chained method calls on a single line without line breaks are harder to read, so some developers place a newline character after each method call in the chain to make it more readable and easy to maintain.
Let's look at the following perfectly valid (but single line) code.
d3.select("body").selectAll("p").data([4, 8, 15, 16, 23, 42 ]).enter().append("p").text(function(d) { return "I'm number " + d + "!"; });
However, with appropriate new lines, it becomes easy to read and understand. Look at the same code written below with line breaks after each call.
d3
.select("body")
.selectAll("p")
.data([
4,
8,
15,
16,
23,
42
])
.enter()
.append("p")
.text(function (d) {
return "I'm number " + d + "!";
});
Another argument in favor of this style is that it improves the clarity of diffs when something in the method chain is changed:
Less clear:
-d3.select("body").selectAll("p").style("color", "white");
+d3.select("body").selectAll("p").style("color", "blue");
More clear:
d3
.select("body")
.selectAll("p")
- .style("color", "white");
+ .style("color", "blue");
Rule Details
This rule requires a newline after each call in a method chain or deep member access. Computed property accesses such as instance[something]
are excluded.
Options
This rule has an object option:
-
"ignoreChainWithDepth"
(default:2
) allows chains up to a specified depth.
ignoreChainWithDepth
Examples of incorrect code for this rule with the default { "ignoreChainWithDepth": 2 }
option:
/*eslint newline-per-chained-call: ["error", { "ignoreChainWithDepth": 2 }]*/
_.chain({}).map(foo).filter(bar).value();
// Or
_.chain({}).map(foo).filter(bar);
// Or
_
.chain({}).map(foo)
.filter(bar);
// Or
obj.method().method2().method3();
Examples of correct code for this rule with the default { "ignoreChainWithDepth": 2 }
option:
/*eslint newline-per-chained-call: ["error", { "ignoreChainWithDepth": 2 }]*/
_
.chain({})
.map(foo)
.filter(bar)
.value();
// Or
_
.chain({})
.map(foo)
.filter(bar);
// Or
_.chain({})
.map(foo)
.filter(bar);
// Or
obj
.prop
.method().prop;
// Or
obj
.prop.method()
.method2()
.method3().prop;
When Not To Use It
If you have conflicting rules or when you are fine with chained calls on one line, you can safely turn this rule off. Source: http://eslint.org/docs/rules/
A constructor name should not start with a lowercase letter. Open
const tenonApi = new tenonNode({
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require constructor names to begin with a capital letter (new-cap)
The new
operator in JavaScript creates a new instance of a particular type of object. That type of object is represented by a constructor function. Since constructor functions are just regular functions, the only defining characteristic is that new
is being used as part of the call. Native JavaScript functions begin with an uppercase letter to distinguish those functions that are to be used as constructors from functions that are not. Many style guides recommend following this pattern to more easily determine which functions are to be used as constructors.
var friend = new Person();
Rule Details
This rule requires constructor names to begin with a capital letter. Certain built-in identifiers are exempt from this rule. These identifiers are:
Array
Boolean
Date
Error
Function
Number
Object
RegExp
String
Symbol
Examples of correct code for this rule:
/*eslint new-cap: "error"*/
function foo(arg) {
return Boolean(arg);
}
Options
This rule has an object option:
-
"newIsCap": true
(default) requires allnew
operators to be called with uppercase-started functions. -
"newIsCap": false
allowsnew
operators to be called with lowercase-started or uppercase-started functions. -
"capIsNew": true
(default) requires all uppercase-started functions to be called withnew
operators. -
"capIsNew": false
allows uppercase-started functions to be called withoutnew
operators. -
"newIsCapExceptions"
allows specified lowercase-started function names to be called with thenew
operator. -
"newIsCapExceptionPattern"
allows any lowercase-started function names that match the specified regex pattern to be called with thenew
operator. -
"capIsNewExceptions"
allows specified uppercase-started function names to be called without thenew
operator. -
"capIsNewExceptionPattern"
allows any uppercase-started function names that match the specified regex pattern to be called without thenew
operator. -
"properties": true
(default) enables checks on object properties -
"properties": false
disables checks on object properties
newIsCap
Examples of incorrect code for this rule with the default { "newIsCap": true }
option:
/*eslint new-cap: ["error", { "newIsCap": true }]*/
var friend = new person();
Examples of correct code for this rule with the default { "newIsCap": true }
option:
/*eslint new-cap: ["error", { "newIsCap": true }]*/
var friend = new Person();
Examples of correct code for this rule with the { "newIsCap": false }
option:
/*eslint new-cap: ["error", { "newIsCap": false }]*/
var friend = new person();
capIsNew
Examples of incorrect code for this rule with the default { "capIsNew": true }
option:
/*eslint new-cap: ["error", { "capIsNew": true }]*/
var colleague = Person();
Examples of correct code for this rule with the default { "capIsNew": true }
option:
/*eslint new-cap: ["error", { "capIsNew": true }]*/
var colleague = new Person();
Examples of correct code for this rule with the { "capIsNew": false }
option:
/*eslint new-cap: ["error", { "capIsNew": false }]*/
var colleague = Person();
newIsCapExceptions
Examples of additional correct code for this rule with the { "newIsCapExceptions": ["events"] }
option:
/*eslint new-cap: ["error", { "newIsCapExceptions": ["events"] }]*/
var events = require('events');
var emitter = new events();
newIsCapExceptionPattern
Examples of additional correct code for this rule with the { "newIsCapExceptionPattern": "^person\.." }
option:
/*eslint new-cap: ["error", { "newIsCapExceptionPattern": "^person\.." }]*/
var friend = new person.acquaintance();
var bestFriend = new person.friend();
capIsNewExceptions
Examples of additional correct code for this rule with the { "capIsNewExceptions": ["Person"] }
option:
/*eslint new-cap: ["error", { "capIsNewExceptions": ["Person"] }]*/
function foo(arg) {
return Person(arg);
}
capIsNewExceptionPattern
Examples of additional correct code for this rule with the { "capIsNewExceptionPattern": "^Person\.." }
option:
/*eslint new-cap: ["error", { "capIsNewExceptionPattern": "^Person\.." }]*/
var friend = person.Acquaintance();
var bestFriend = person.Friend();
properties
Examples of incorrect code for this rule with the default { "properties": true }
option:
/*eslint new-cap: ["error", { "properties": true }]*/
var friend = new person.acquaintance();
Examples of correct code for this rule with the default { "properties": true }
option:
/*eslint new-cap: ["error", { "properties": true }]*/
var friend = new person.Acquaintance();
Examples of correct code for this rule with the { "properties": false }
option:
/*eslint new-cap: ["error", { "properties": false }]*/
var friend = new person.acquaintance();
When Not To Use It
If you have conventions that don't require an uppercase letter for constructors, or don't require capitalized functions be only used as constructors, turn this rule off. Source: http://eslint.org/docs/rules/
Unexpected console statement. Open
console.log('Sending request to Tenon...');
- Read upRead up
- Exclude checks
disallow the use of console
(no-console)
In JavaScript that is designed to be executed in the browser, it's considered a best practice to avoid using methods on console
. Such messages are considered to be for debugging purposes and therefore not suitable to ship to the client. In general, calls using console
should be stripped before being pushed to production.
console.log("Made it here.");
console.error("That shouldn't have happened.");
Rule Details
This rule disallows calls to methods of the console
object.
Examples of incorrect code for this rule:
/*eslint no-console: "error"*/
console.log("Log a debug level message.");
console.warn("Log a warn level message.");
console.error("Log an error level message.");
Examples of correct code for this rule:
/*eslint no-console: "error"*/
// custom console
Console.log("Hello world!");
Options
This rule has an object option for exceptions:
-
"allow"
has an array of strings which are allowed methods of theconsole
object
Examples of additional correct code for this rule with a sample { "allow": ["warn", "error"] }
option:
/*eslint no-console: ["error", { allow: ["warn", "error"] }] */
console.warn("Log a warn level message.");
console.error("Log an error level message.");
When Not To Use It
If you're using Node.js, however, console
is used to output information to the user and so is not strictly used for debugging purposes. If you are developing for Node.js then you most likely do not want this rule enabled.
Related Rules
- [no-alert](no-alert.md)
- [no-debugger](no-debugger.md) Source: http://eslint.org/docs/rules/
Expected line break before .option
. Open
).option(
- Read upRead up
- Exclude checks
require a newline after each call in a method chain (newline-per-chained-call)
Chained method calls on a single line without line breaks are harder to read, so some developers place a newline character after each method call in the chain to make it more readable and easy to maintain.
Let's look at the following perfectly valid (but single line) code.
d3.select("body").selectAll("p").data([4, 8, 15, 16, 23, 42 ]).enter().append("p").text(function(d) { return "I'm number " + d + "!"; });
However, with appropriate new lines, it becomes easy to read and understand. Look at the same code written below with line breaks after each call.
d3
.select("body")
.selectAll("p")
.data([
4,
8,
15,
16,
23,
42
])
.enter()
.append("p")
.text(function (d) {
return "I'm number " + d + "!";
});
Another argument in favor of this style is that it improves the clarity of diffs when something in the method chain is changed:
Less clear:
-d3.select("body").selectAll("p").style("color", "white");
+d3.select("body").selectAll("p").style("color", "blue");
More clear:
d3
.select("body")
.selectAll("p")
- .style("color", "white");
+ .style("color", "blue");
Rule Details
This rule requires a newline after each call in a method chain or deep member access. Computed property accesses such as instance[something]
are excluded.
Options
This rule has an object option:
-
"ignoreChainWithDepth"
(default:2
) allows chains up to a specified depth.
ignoreChainWithDepth
Examples of incorrect code for this rule with the default { "ignoreChainWithDepth": 2 }
option:
/*eslint newline-per-chained-call: ["error", { "ignoreChainWithDepth": 2 }]*/
_.chain({}).map(foo).filter(bar).value();
// Or
_.chain({}).map(foo).filter(bar);
// Or
_
.chain({}).map(foo)
.filter(bar);
// Or
obj.method().method2().method3();
Examples of correct code for this rule with the default { "ignoreChainWithDepth": 2 }
option:
/*eslint newline-per-chained-call: ["error", { "ignoreChainWithDepth": 2 }]*/
_
.chain({})
.map(foo)
.filter(bar)
.value();
// Or
_
.chain({})
.map(foo)
.filter(bar);
// Or
_.chain({})
.map(foo)
.filter(bar);
// Or
obj
.prop
.method().prop;
// Or
obj
.prop.method()
.method2()
.method3().prop;
When Not To Use It
If you have conflicting rules or when you are fine with chained calls on one line, you can safely turn this rule off. Source: http://eslint.org/docs/rules/
Unexpected console statement. Open
console.log('\'' + field + '\' is required');
- Read upRead up
- Exclude checks
disallow the use of console
(no-console)
In JavaScript that is designed to be executed in the browser, it's considered a best practice to avoid using methods on console
. Such messages are considered to be for debugging purposes and therefore not suitable to ship to the client. In general, calls using console
should be stripped before being pushed to production.
console.log("Made it here.");
console.error("That shouldn't have happened.");
Rule Details
This rule disallows calls to methods of the console
object.
Examples of incorrect code for this rule:
/*eslint no-console: "error"*/
console.log("Log a debug level message.");
console.warn("Log a warn level message.");
console.error("Log an error level message.");
Examples of correct code for this rule:
/*eslint no-console: "error"*/
// custom console
Console.log("Hello world!");
Options
This rule has an object option for exceptions:
-
"allow"
has an array of strings which are allowed methods of theconsole
object
Examples of additional correct code for this rule with a sample { "allow": ["warn", "error"] }
option:
/*eslint no-console: ["error", { allow: ["warn", "error"] }] */
console.warn("Log a warn level message.");
console.error("Log an error level message.");
When Not To Use It
If you're using Node.js, however, console
is used to output information to the user and so is not strictly used for debugging purposes. If you are developing for Node.js then you most likely do not want this rule enabled.
Related Rules
- [no-alert](no-alert.md)
- [no-debugger](no-debugger.md) Source: http://eslint.org/docs/rules/
Unexpected console statement. Open
console.log('Tenon analysis completed.');
- Read upRead up
- Exclude checks
disallow the use of console
(no-console)
In JavaScript that is designed to be executed in the browser, it's considered a best practice to avoid using methods on console
. Such messages are considered to be for debugging purposes and therefore not suitable to ship to the client. In general, calls using console
should be stripped before being pushed to production.
console.log("Made it here.");
console.error("That shouldn't have happened.");
Rule Details
This rule disallows calls to methods of the console
object.
Examples of incorrect code for this rule:
/*eslint no-console: "error"*/
console.log("Log a debug level message.");
console.warn("Log a warn level message.");
console.error("Log an error level message.");
Examples of correct code for this rule:
/*eslint no-console: "error"*/
// custom console
Console.log("Hello world!");
Options
This rule has an object option for exceptions:
-
"allow"
has an array of strings which are allowed methods of theconsole
object
Examples of additional correct code for this rule with a sample { "allow": ["warn", "error"] }
option:
/*eslint no-console: ["error", { allow: ["warn", "error"] }] */
console.warn("Log a warn level message.");
console.error("Log an error level message.");
When Not To Use It
If you're using Node.js, however, console
is used to output information to the user and so is not strictly used for debugging purposes. If you are developing for Node.js then you most likely do not want this rule enabled.
Related Rules
- [no-alert](no-alert.md)
- [no-debugger](no-debugger.md) Source: http://eslint.org/docs/rules/
Unexpected console statement. Open
console.log('Writing results to file...');
- Read upRead up
- Exclude checks
disallow the use of console
(no-console)
In JavaScript that is designed to be executed in the browser, it's considered a best practice to avoid using methods on console
. Such messages are considered to be for debugging purposes and therefore not suitable to ship to the client. In general, calls using console
should be stripped before being pushed to production.
console.log("Made it here.");
console.error("That shouldn't have happened.");
Rule Details
This rule disallows calls to methods of the console
object.
Examples of incorrect code for this rule:
/*eslint no-console: "error"*/
console.log("Log a debug level message.");
console.warn("Log a warn level message.");
console.error("Log an error level message.");
Examples of correct code for this rule:
/*eslint no-console: "error"*/
// custom console
Console.log("Hello world!");
Options
This rule has an object option for exceptions:
-
"allow"
has an array of strings which are allowed methods of theconsole
object
Examples of additional correct code for this rule with a sample { "allow": ["warn", "error"] }
option:
/*eslint no-console: ["error", { allow: ["warn", "error"] }] */
console.warn("Log a warn level message.");
console.error("Log an error level message.");
When Not To Use It
If you're using Node.js, however, console
is used to output information to the user and so is not strictly used for debugging purposes. If you are developing for Node.js then you most likely do not want this rule enabled.
Related Rules
- [no-alert](no-alert.md)
- [no-debugger](no-debugger.md) Source: http://eslint.org/docs/rules/
Trailing spaces not allowed. Open
- Read upRead up
- Exclude checks
disallow trailing whitespace at the end of lines (no-trailing-spaces)
Sometimes in the course of editing files, you can end up with extra whitespace at the end of lines. These whitespace differences can be picked up by source control systems and flagged as diffs, causing frustration for developers. While this extra whitespace causes no functional issues, many code conventions require that trailing spaces be removed before check-in.
Rule Details
This rule disallows trailing whitespace (spaces, tabs, and other Unicode whitespace characters) at the end of lines.
Examples of incorrect code for this rule:
/*eslint no-trailing-spaces: "error"*/
var foo = 0;//•••••
var baz = 5;//••
//•••••
Examples of correct code for this rule:
/*eslint no-trailing-spaces: "error"*/
var foo = 0;
var baz = 5;
Options
This rule has an object option:
-
"skipBlankLines": false
(default) disallows trailing whitespace on empty lines -
"skipBlankLines": true
allows trailing whitespace on empty lines
skipBlankLines
Examples of correct code for this rule with the { "skipBlankLines": true }
option:
/*eslint no-trailing-spaces: ["error", { "skipBlankLines": true }]*/
var foo = 0;
var baz = 5;
//•••••
Source: http://eslint.org/docs/rules/
Unexpected require(). Open
reporter: require('jshint-stylish')
- Read upRead up
- Exclude checks
Enforce require() on the top-level module scope (global-require)
In Node.js, module dependencies are included using the require()
function, such as:
var fs = require("fs");
While require()
may be called anywhere in code, some style guides prescribe that it should be called only in the top level of a module to make it easier to identify dependencies. For instance, it's arguably harder to identify dependencies when they are deeply nested inside of functions and other statements:
function foo() {
if (condition) {
var fs = require("fs");
}
}
Since require()
does a synchronous load, it can cause performance problems when used in other locations.
Further, ES6 modules mandate that import
and export
statements can only occur in the top level of the module's body.
Rule Details
This rule requires all calls to require()
to be at the top level of the module, similar to ES6 import
and export
statements, which also can occur only at the top level.
Examples of incorrect code for this rule:
/*eslint global-require: "error"*/
/*eslint-env es6*/
// calling require() inside of a function is not allowed
function readFile(filename, callback) {
var fs = require('fs');
fs.readFile(filename, callback)
}
// conditional requires like this are also not allowed
if (DEBUG) { require('debug'); }
// a require() in a switch statement is also flagged
switch(x) { case '1': require('1'); break; }
// you may not require() inside an arrow function body
var getModule = (name) => require(name);
// you may not require() inside of a function body as well
function getModule(name) { return require(name); }
// you may not require() inside of a try/catch block
try {
require(unsafeModule);
} catch(e) {
console.log(e);
}
Examples of correct code for this rule:
/*eslint global-require: "error"*/
// all these variations of require() are ok
require('x');
var y = require('y');
var z;
z = require('z').initialize();
// requiring a module and using it in a function is ok
var fs = require('fs');
function readFile(filename, callback) {
fs.readFile(filename, callback)
}
// you can use a ternary to determine which module to require
var logger = DEBUG ? require('dev-logger') : require('logger');
// if you want you can require() at the end of your module
function doSomethingA() {}
function doSomethingB() {}
var x = require("x"),
z = require("z");
When Not To Use It
If you have a module that must be initialized with information that comes from the file-system or if a module is only used in very rare situations and will cause significant overhead to load it may make sense to disable the rule. If you need to require()
an optional dependency inside of a try
/catch
, you can disable this rule for just that dependency using the // eslint-disable-line global-require
comment.
Source: http://eslint.org/docs/rules/
Expected indentation of 18 spaces but found 20. Open
jshintrc: '.jshintrc'
- 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/
Import and Export Declarations are not supported yet on Node v4. Open
export const parseCommand = function(passedArguments) {
- Read upRead up
- Exclude checks
For more information visit Source: http://eslint.org/docs/rules/
Expected line break before .option
. Open
).option(
- Read upRead up
- Exclude checks
require a newline after each call in a method chain (newline-per-chained-call)
Chained method calls on a single line without line breaks are harder to read, so some developers place a newline character after each method call in the chain to make it more readable and easy to maintain.
Let's look at the following perfectly valid (but single line) code.
d3.select("body").selectAll("p").data([4, 8, 15, 16, 23, 42 ]).enter().append("p").text(function(d) { return "I'm number " + d + "!"; });
However, with appropriate new lines, it becomes easy to read and understand. Look at the same code written below with line breaks after each call.
d3
.select("body")
.selectAll("p")
.data([
4,
8,
15,
16,
23,
42
])
.enter()
.append("p")
.text(function (d) {
return "I'm number " + d + "!";
});
Another argument in favor of this style is that it improves the clarity of diffs when something in the method chain is changed:
Less clear:
-d3.select("body").selectAll("p").style("color", "white");
+d3.select("body").selectAll("p").style("color", "blue");
More clear:
d3
.select("body")
.selectAll("p")
- .style("color", "white");
+ .style("color", "blue");
Rule Details
This rule requires a newline after each call in a method chain or deep member access. Computed property accesses such as instance[something]
are excluded.
Options
This rule has an object option:
-
"ignoreChainWithDepth"
(default:2
) allows chains up to a specified depth.
ignoreChainWithDepth
Examples of incorrect code for this rule with the default { "ignoreChainWithDepth": 2 }
option:
/*eslint newline-per-chained-call: ["error", { "ignoreChainWithDepth": 2 }]*/
_.chain({}).map(foo).filter(bar).value();
// Or
_.chain({}).map(foo).filter(bar);
// Or
_
.chain({}).map(foo)
.filter(bar);
// Or
obj.method().method2().method3();
Examples of correct code for this rule with the default { "ignoreChainWithDepth": 2 }
option:
/*eslint newline-per-chained-call: ["error", { "ignoreChainWithDepth": 2 }]*/
_
.chain({})
.map(foo)
.filter(bar)
.value();
// Or
_
.chain({})
.map(foo)
.filter(bar);
// Or
_.chain({})
.map(foo)
.filter(bar);
// Or
obj
.prop
.method().prop;
// Or
obj
.prop.method()
.method2()
.method3().prop;
When Not To Use It
If you have conflicting rules or when you are fine with chained calls on one line, you can safely turn this rule off. Source: http://eslint.org/docs/rules/
Unexpected unnamed function. Open
return Object.keys(program).filter(function(opt) {
- Read upRead up
- Exclude checks
Require or disallow named function
expressions (func-names)
A pattern that's becoming more common is to give function expressions names to aid in debugging. For example:
Foo.prototype.bar = function bar() {};
Adding the second bar
in the above example is optional. If you leave off the function name then when the function throws an exception you are likely to get something similar to anonymous function
in the stack trace. If you provide the optional name for a function expression then you will get the name of the function expression in the stack trace.
Rule Details
This rule can enforce or disallow the use of named function expressions.
Options
This rule has a string option:
-
"always"
(default) requires function expressions to have a name -
"as-needed"
requires function expressions to have a name, if the name cannot be assigned automatically in an ES6 environment -
"never"
disallows named function expressions, except in recursive functions, where a name is needed
always
Examples of incorrect code for this rule with the default "always"
option:
/*eslint func-names: ["error", "always"]*/
Foo.prototype.bar = function() {};
(function() {
// ...
}())
Examples of correct code for this rule with the default "always"
option:
/*eslint func-names: ["error", "always"]*/
Foo.prototype.bar = function bar() {};
(function bar() {
// ...
}())
as-needed
ECMAScript 6 introduced a name
property on all functions. The value of name
is determined by evaluating the code around the function to see if a name can be inferred. For example, a function assigned to a variable will automatically have a name
property equal to the name of the variable. The value of name
is then used in stack traces for easier debugging.
Examples of incorrect code for this rule with the default "as-needed"
option:
/*eslint func-names: ["error", "as-needed"]*/
Foo.prototype.bar = function() {};
(function() {
// ...
}())
Examples of correct code for this rule with the default "as-needed"
option:
/*eslint func-names: ["error", "as-needed"]*/
var bar = function() {};
(function bar() {
// ...
}())
never
Examples of incorrect code for this rule with the "never"
option:
/*eslint func-names: ["error", "never"]*/
Foo.prototype.bar = function bar() {};
(function bar() {
// ...
}())
Examples of correct code for this rule with the "never"
option:
/*eslint func-names: ["error", "never"]*/
Foo.prototype.bar = function() {};
(function() {
// ...
}())
Further Reading
Compatibility
- JSCS: requireAnonymousFunctions
- JSCS: disallowAnonymousFunctions Source: http://eslint.org/docs/rules/
Unexpected function expression. Open
return Object.keys(program).filter(function(opt) {
- 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/
Import and Export Declarations are not supported yet on Node v4. Open
import { parseCommand } from './';
- Read upRead up
- Exclude checks
For more information visit Source: http://eslint.org/docs/rules/
Unexpected console statement. Open
console.error(err);
- Read upRead up
- Exclude checks
disallow the use of console
(no-console)
In JavaScript that is designed to be executed in the browser, it's considered a best practice to avoid using methods on console
. Such messages are considered to be for debugging purposes and therefore not suitable to ship to the client. In general, calls using console
should be stripped before being pushed to production.
console.log("Made it here.");
console.error("That shouldn't have happened.");
Rule Details
This rule disallows calls to methods of the console
object.
Examples of incorrect code for this rule:
/*eslint no-console: "error"*/
console.log("Log a debug level message.");
console.warn("Log a warn level message.");
console.error("Log an error level message.");
Examples of correct code for this rule:
/*eslint no-console: "error"*/
// custom console
Console.log("Hello world!");
Options
This rule has an object option for exceptions:
-
"allow"
has an array of strings which are allowed methods of theconsole
object
Examples of additional correct code for this rule with a sample { "allow": ["warn", "error"] }
option:
/*eslint no-console: ["error", { allow: ["warn", "error"] }] */
console.warn("Log a warn level message.");
console.error("Log an error level message.");
When Not To Use It
If you're using Node.js, however, console
is used to output information to the user and so is not strictly used for debugging purposes. If you are developing for Node.js then you most likely do not want this rule enabled.
Related Rules
- [no-alert](no-alert.md)
- [no-debugger](no-debugger.md) Source: http://eslint.org/docs/rules/
Expected indentation of 6 spaces but found 8. Open
pkg: grunt.file.readJSON('package.json'),
- 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
jshint: {
- 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
options: {
- 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/