Showing 4 of 4 total issues
Expected newline after "use strict" directive. Open
'use strict'
- Read upRead up
- Exclude checks
require or disallow newlines around directives (lines-around-directive)
Directives are used in JavaScript to indicate to the execution environment that a script would like to opt into a feature such as "strict mode"
. Directives are grouped together in a directive prologue at the top of either a file or function block and are applied to the scope in which they occur.
// Strict mode is invoked for the entire script
"use strict";
var foo;
function bar() {
var baz;
}
var foo;
function bar() {
// Strict mode is only invoked within this function
"use strict";
var baz;
}
Rule Details
This rule requires or disallows blank newlines around directive prologues. This rule does not enforce any conventions about blank newlines between the individual directives. In addition, it does not require blank newlines before directive prologues unless they are preceded by a comment. Please use the [padded-blocks](padded-blocks.md) rule if this is a style you would like to enforce.
Options
This rule has one option. It can either be a string or an object:
-
"always"
(default) enforces blank newlines around directives. -
"never"
disallows blank newlines around directives.
or
{
"before": "always" or "never"
"after": "always" or "never",
}
always
This is the default option.
Examples of incorrect code for this rule with the "always"
option:
/* eslint lines-around-directive: ["error", "always"] */
/* Top of file */
"use strict";
var foo;
/* Top of file */
// comment
"use strict";
"use asm";
var foo;
function foo() {
"use strict";
"use asm";
var bar;
}
function foo() {
// comment
"use strict";
var bar;
}
Examples of correct code for this rule with the "always"
option:
/* eslint lines-around-directive: ["error", "always"] */
/* Top of file */
"use strict";
var foo;
/* Top of file */
// comment
"use strict";
"use asm";
var foo;
function foo() {
"use strict";
"use asm";
var bar;
}
function foo() {
// comment
"use strict";
var bar;
}
never
Examples of incorrect code for this rule with the "never"
option:
/* eslint lines-around-directive: ["error", "never"] */
/* Top of file */
"use strict";
var foo;
/* Top of file */
// comment
"use strict";
"use asm";
var foo;
function foo() {
"use strict";
"use asm";
var bar;
}
function foo() {
// comment
"use strict";
var bar;
}
Examples of correct code for this rule with the "never"
option:
/* eslint lines-around-directive: ["error", "never"] */
/* Top of file */
"use strict";
var foo;
/* Top of file */
// comment
"use strict";
"use asm";
var foo;
function foo() {
"use strict";
"use asm";
var bar;
}
function foo() {
// comment
"use strict";
var bar;
}
before & after
Examples of incorrect code for this rule with the { "before": "never", "after": "always" }
option:
/* eslint lines-around-directive: ["error", { "before": "never", "after": "always" }] */
/* Top of file */
"use strict";
var foo;
/* Top of file */
// comment
"use strict";
"use asm";
var foo;
function foo() {
"use strict";
"use asm";
var bar;
}
function foo() {
// comment
"use strict";
var bar;
}
Examples of correct code for this rule with the { "before": "never", "after": "always" }
option:
/* eslint lines-around-directive: ["error", { "before": "never", "after": "always" }] */
/* Top of file */
"use strict";
var foo;
/* Top of file */
// comment
"use strict";
"use asm";
var foo;
function foo() {
"use strict";
"use asm";
var bar;
}
function foo() {
// comment
"use strict";
var bar;
}
Examples of incorrect code for this rule with the { "before": "always", "after": "never" }
option:
/* eslint lines-around-directive: ["error", { "before": "always", "after": "never" }] */
/* Top of file */
"use strict";
var foo;
/* Top of file */
// comment
"use strict";
"use asm";
var foo;
function foo() {
"use strict";
"use asm";
var bar;
}
function foo() {
// comment
"use strict";
var bar;
}
Examples of correct code for this rule with the { "before": "always", "after": "never" }
option:
/* eslint lines-around-directive: ["error", { "before": "always", "after": "never" }] */
/* Top of file */
"use strict";
var foo;
/* Top of file */
// comment
"use strict";
"use asm";
var foo;
function foo() {
"use strict";
"use asm";
var bar;
}
function foo() {
// comment
"use strict";
var bar;
}
When Not To Use It
You can safely disable this rule if you do not have any strict conventions about whether or not directive prologues should have blank newlines before or after them.
Related Rules
- [lines-around-comment](lines-around-comment.md)
- [padded-blocks](padded-blocks.md)
Compatibility
Expected newline after "use strict" directive. Open
'use strict'
- Read upRead up
- Exclude checks
require or disallow newlines around directives (lines-around-directive)
Directives are used in JavaScript to indicate to the execution environment that a script would like to opt into a feature such as "strict mode"
. Directives are grouped together in a directive prologue at the top of either a file or function block and are applied to the scope in which they occur.
// Strict mode is invoked for the entire script
"use strict";
var foo;
function bar() {
var baz;
}
var foo;
function bar() {
// Strict mode is only invoked within this function
"use strict";
var baz;
}
Rule Details
This rule requires or disallows blank newlines around directive prologues. This rule does not enforce any conventions about blank newlines between the individual directives. In addition, it does not require blank newlines before directive prologues unless they are preceded by a comment. Please use the [padded-blocks](padded-blocks.md) rule if this is a style you would like to enforce.
Options
This rule has one option. It can either be a string or an object:
-
"always"
(default) enforces blank newlines around directives. -
"never"
disallows blank newlines around directives.
or
{
"before": "always" or "never"
"after": "always" or "never",
}
always
This is the default option.
Examples of incorrect code for this rule with the "always"
option:
/* eslint lines-around-directive: ["error", "always"] */
/* Top of file */
"use strict";
var foo;
/* Top of file */
// comment
"use strict";
"use asm";
var foo;
function foo() {
"use strict";
"use asm";
var bar;
}
function foo() {
// comment
"use strict";
var bar;
}
Examples of correct code for this rule with the "always"
option:
/* eslint lines-around-directive: ["error", "always"] */
/* Top of file */
"use strict";
var foo;
/* Top of file */
// comment
"use strict";
"use asm";
var foo;
function foo() {
"use strict";
"use asm";
var bar;
}
function foo() {
// comment
"use strict";
var bar;
}
never
Examples of incorrect code for this rule with the "never"
option:
/* eslint lines-around-directive: ["error", "never"] */
/* Top of file */
"use strict";
var foo;
/* Top of file */
// comment
"use strict";
"use asm";
var foo;
function foo() {
"use strict";
"use asm";
var bar;
}
function foo() {
// comment
"use strict";
var bar;
}
Examples of correct code for this rule with the "never"
option:
/* eslint lines-around-directive: ["error", "never"] */
/* Top of file */
"use strict";
var foo;
/* Top of file */
// comment
"use strict";
"use asm";
var foo;
function foo() {
"use strict";
"use asm";
var bar;
}
function foo() {
// comment
"use strict";
var bar;
}
before & after
Examples of incorrect code for this rule with the { "before": "never", "after": "always" }
option:
/* eslint lines-around-directive: ["error", { "before": "never", "after": "always" }] */
/* Top of file */
"use strict";
var foo;
/* Top of file */
// comment
"use strict";
"use asm";
var foo;
function foo() {
"use strict";
"use asm";
var bar;
}
function foo() {
// comment
"use strict";
var bar;
}
Examples of correct code for this rule with the { "before": "never", "after": "always" }
option:
/* eslint lines-around-directive: ["error", { "before": "never", "after": "always" }] */
/* Top of file */
"use strict";
var foo;
/* Top of file */
// comment
"use strict";
"use asm";
var foo;
function foo() {
"use strict";
"use asm";
var bar;
}
function foo() {
// comment
"use strict";
var bar;
}
Examples of incorrect code for this rule with the { "before": "always", "after": "never" }
option:
/* eslint lines-around-directive: ["error", { "before": "always", "after": "never" }] */
/* Top of file */
"use strict";
var foo;
/* Top of file */
// comment
"use strict";
"use asm";
var foo;
function foo() {
"use strict";
"use asm";
var bar;
}
function foo() {
// comment
"use strict";
var bar;
}
Examples of correct code for this rule with the { "before": "always", "after": "never" }
option:
/* eslint lines-around-directive: ["error", { "before": "always", "after": "never" }] */
/* Top of file */
"use strict";
var foo;
/* Top of file */
// comment
"use strict";
"use asm";
var foo;
function foo() {
"use strict";
"use asm";
var bar;
}
function foo() {
// comment
"use strict";
var bar;
}
When Not To Use It
You can safely disable this rule if you do not have any strict conventions about whether or not directive prologues should have blank newlines before or after them.
Related Rules
- [lines-around-comment](lines-around-comment.md)
- [padded-blocks](padded-blocks.md)
Compatibility
Expected newline before "use strict" directive. Open
'use strict'
- Read upRead up
- Exclude checks
require or disallow newlines around directives (lines-around-directive)
Directives are used in JavaScript to indicate to the execution environment that a script would like to opt into a feature such as "strict mode"
. Directives are grouped together in a directive prologue at the top of either a file or function block and are applied to the scope in which they occur.
// Strict mode is invoked for the entire script
"use strict";
var foo;
function bar() {
var baz;
}
var foo;
function bar() {
// Strict mode is only invoked within this function
"use strict";
var baz;
}
Rule Details
This rule requires or disallows blank newlines around directive prologues. This rule does not enforce any conventions about blank newlines between the individual directives. In addition, it does not require blank newlines before directive prologues unless they are preceded by a comment. Please use the [padded-blocks](padded-blocks.md) rule if this is a style you would like to enforce.
Options
This rule has one option. It can either be a string or an object:
-
"always"
(default) enforces blank newlines around directives. -
"never"
disallows blank newlines around directives.
or
{
"before": "always" or "never"
"after": "always" or "never",
}
always
This is the default option.
Examples of incorrect code for this rule with the "always"
option:
/* eslint lines-around-directive: ["error", "always"] */
/* Top of file */
"use strict";
var foo;
/* Top of file */
// comment
"use strict";
"use asm";
var foo;
function foo() {
"use strict";
"use asm";
var bar;
}
function foo() {
// comment
"use strict";
var bar;
}
Examples of correct code for this rule with the "always"
option:
/* eslint lines-around-directive: ["error", "always"] */
/* Top of file */
"use strict";
var foo;
/* Top of file */
// comment
"use strict";
"use asm";
var foo;
function foo() {
"use strict";
"use asm";
var bar;
}
function foo() {
// comment
"use strict";
var bar;
}
never
Examples of incorrect code for this rule with the "never"
option:
/* eslint lines-around-directive: ["error", "never"] */
/* Top of file */
"use strict";
var foo;
/* Top of file */
// comment
"use strict";
"use asm";
var foo;
function foo() {
"use strict";
"use asm";
var bar;
}
function foo() {
// comment
"use strict";
var bar;
}
Examples of correct code for this rule with the "never"
option:
/* eslint lines-around-directive: ["error", "never"] */
/* Top of file */
"use strict";
var foo;
/* Top of file */
// comment
"use strict";
"use asm";
var foo;
function foo() {
"use strict";
"use asm";
var bar;
}
function foo() {
// comment
"use strict";
var bar;
}
before & after
Examples of incorrect code for this rule with the { "before": "never", "after": "always" }
option:
/* eslint lines-around-directive: ["error", { "before": "never", "after": "always" }] */
/* Top of file */
"use strict";
var foo;
/* Top of file */
// comment
"use strict";
"use asm";
var foo;
function foo() {
"use strict";
"use asm";
var bar;
}
function foo() {
// comment
"use strict";
var bar;
}
Examples of correct code for this rule with the { "before": "never", "after": "always" }
option:
/* eslint lines-around-directive: ["error", { "before": "never", "after": "always" }] */
/* Top of file */
"use strict";
var foo;
/* Top of file */
// comment
"use strict";
"use asm";
var foo;
function foo() {
"use strict";
"use asm";
var bar;
}
function foo() {
// comment
"use strict";
var bar;
}
Examples of incorrect code for this rule with the { "before": "always", "after": "never" }
option:
/* eslint lines-around-directive: ["error", { "before": "always", "after": "never" }] */
/* Top of file */
"use strict";
var foo;
/* Top of file */
// comment
"use strict";
"use asm";
var foo;
function foo() {
"use strict";
"use asm";
var bar;
}
function foo() {
// comment
"use strict";
var bar;
}
Examples of correct code for this rule with the { "before": "always", "after": "never" }
option:
/* eslint lines-around-directive: ["error", { "before": "always", "after": "never" }] */
/* Top of file */
"use strict";
var foo;
/* Top of file */
// comment
"use strict";
"use asm";
var foo;
function foo() {
"use strict";
"use asm";
var bar;
}
function foo() {
// comment
"use strict";
var bar;
}
When Not To Use It
You can safely disable this rule if you do not have any strict conventions about whether or not directive prologues should have blank newlines before or after them.
Related Rules
- [lines-around-comment](lines-around-comment.md)
- [padded-blocks](padded-blocks.md)
Compatibility
Unary operator '++' used. Open
for (let i = 0; i < listeners.length; i++) {
- Read upRead up
- Exclude checks
disallow the unary operators ++
and --
(no-plusplus)
Because the unary ++
and --
operators are subject to automatic semicolon insertion, differences in whitespace can change semantics of source code.
var i = 10;
var j = 20;
i ++
j
// i = 11, j = 20
var i = 10;
var j = 20;
i
++
j
// i = 10, j = 21
Rule Details
This rule disallows the unary operators ++
and --
.
Examples of incorrect code for this rule:
/*eslint no-plusplus: "error"*/
var foo = 0;
foo++;
var bar = 42;
bar--;
for (i = 0; i < l; i++) {
return;
}
Examples of correct code for this rule:
/*eslint no-plusplus: "error"*/
var foo = 0;
foo += 1;
var bar = 42;
bar -= 1;
for (i = 0; i < l; i += 1) {
return;
}
Options
This rule has an object option.
-
"allowForLoopAfterthoughts": true
allows unary operators++
and--
in the afterthought (final expression) of afor
loop.
allowForLoopAfterthoughts
Examples of correct code for this rule with the { "allowForLoopAfterthoughts": true }
option:
/*eslint no-plusplus: ["error", { "allowForLoopAfterthoughts": true }]*/
for (i = 0; i < l; i++) {
return;
}
for (i = 0; i < l; i--) {
return;
}
Source: http://eslint.org/docs/rules/