There should be no space after '['. Open
methods: [ 'method' ],
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Disallow or enforce spaces inside of brackets (array-bracket-spacing)
A number of style guides require or disallow spaces between array brackets and other tokens. This rule applies to both array literals and destructuring assignments (ECMAScript 6).
/*eslint-env es6*/
var arr = [ 'foo', 'bar' ];
var [ x, y ] = z;
var arr = ['foo', 'bar'];
var [x,y] = z;
Rule Details
This rule enforces consistent spacing inside array brackets.
Options
This rule has a string option:
-
"never"
(default) disallows spaces inside array brackets -
"always"
requires one or more spaces or newlines inside array brackets
This rule has an object option for exceptions to the "never"
option:
-
"singleValue": true
requires one or more spaces or newlines inside brackets of array literals that contain a single element -
"objectsInArrays": true
requires one or more spaces or newlines between brackets of array literals and braces of their object literal elements[ {
or} ]
-
"arraysInArrays": true
requires one or more spaces or newlines between brackets of array literals and brackets of their array literal elements[ [
or] ]
This rule has an object option for exceptions to the "always"
option:
-
"singleValue": false
disallows spaces inside brackets of array literals that contain a single element -
"objectsInArrays": false
disallows spaces between brackets of array literals and braces of their object literal elements[{
or}]
-
"arraysInArrays": false
disallows spaces between brackets of array literals and brackets of their array literal elements[[
or]]
This rule has built-in exceptions:
-
"never"
(and also the exceptions to the"always"
option) allows newlines inside array brackets, because this is a common pattern -
"always"
does not require spaces or newlines in empty array literals[]
never
Examples of incorrect code for this rule with the default "never"
option:
/*eslint array-bracket-spacing: ["error", "never"]*/
/*eslint-env es6*/
var arr = [ 'foo', 'bar' ];
var arr = ['foo', 'bar' ];
var arr = [ ['foo'], 'bar'];
var arr = [[ 'foo' ], 'bar'];
var arr = [ 'foo',
'bar'
];
var [ x, y ] = z;
var [ x,y ] = z;
var [ x, ...y ] = z;
var [ ,,x, ] = z;
Examples of correct code for this rule with the default "never"
option:
/*eslint array-bracket-spacing: ["error", "never"]*/
/*eslint-env es6*/
var arr = [];
var arr = ['foo', 'bar', 'baz'];
var arr = [['foo'], 'bar', 'baz'];
var arr = [
'foo',
'bar',
'baz'
];
var arr = ['foo',
'bar'
];
var arr = [
'foo',
'bar'];
var [x, y] = z;
var [x,y] = z;
var [x, ...y] = z;
var [,,x,] = z;
always
Examples of incorrect code for this rule with the "always"
option:
/*eslint array-bracket-spacing: ["error", "always"]*/
/*eslint-env es6*/
var arr = ['foo', 'bar'];
var arr = ['foo', 'bar' ];
var arr = [ ['foo'], 'bar' ];
var arr = ['foo',
'bar'
];
var arr = [
'foo',
'bar'];
var [x, y] = z;
var [x,y] = z;
var [x, ...y] = z;
var [,,x,] = z;
Examples of correct code for this rule with the "always"
option:
/*eslint array-bracket-spacing: ["error", "always"]*/
/*eslint-env es6*/
var arr = [];
var arr = [ 'foo', 'bar', 'baz' ];
var arr = [ [ 'foo' ], 'bar', 'baz' ];
var arr = [ 'foo',
'bar'
];
var arr = [
'foo',
'bar' ];
var arr = [
'foo',
'bar',
'baz'
];
var [ x, y ] = z;
var [ x,y ] = z;
var [ x, ...y ] = z;
var [ ,,x, ] = z;
singleValue
Examples of incorrect code for this rule with the "always", { "singleValue": false }
options:
/*eslint array-bracket-spacing: ["error", "always", { "singleValue": false }]*/
var foo = [ 'foo' ];
var foo = [ 'foo'];
var foo = ['foo' ];
var foo = [ 1 ];
var foo = [ 1];
var foo = [1 ];
var foo = [ [ 1, 2 ] ];
var foo = [ { 'foo': 'bar' } ];
Examples of correct code for this rule with the "always", { "singleValue": false }
options:
/*eslint array-bracket-spacing: ["error", "always", { "singleValue": false }]*/
var foo = ['foo'];
var foo = [1];
var foo = [[ 1, 1 ]];
var foo = [{ 'foo': 'bar' }];
objectsInArrays
Examples of incorrect code for this rule with the "always", { "objectsInArrays": false }
options:
/*eslint array-bracket-spacing: ["error", "always", { "objectsInArrays": false }]*/
var arr = [ { 'foo': 'bar' } ];
var arr = [ {
'foo': 'bar'
} ]
Examples of correct code for this rule with the "always", { "objectsInArrays": false }
options:
/*eslint array-bracket-spacing: ["error", "always", { "objectsInArrays": false }]*/
var arr = [{ 'foo': 'bar' }];
var arr = [{
'foo': 'bar'
}];
arraysInArrays
Examples of incorrect code for this rule with the "always", { "arraysInArrays": false }
options:
/*eslint array-bracket-spacing: ["error", "always", { "arraysInArrays": false }]*/
var arr = [ [ 1, 2 ], 2, 3, 4 ];
var arr = [ [ 1, 2 ], 2, [ 3, 4 ] ];
Examples of correct code for this rule with the "always", { "arraysInArrays": false }
options:
/*eslint array-bracket-spacing: ["error", "always", { "arraysInArrays": false }]*/
var arr = [[ 1, 2 ], 2, 3, 4 ];
var arr = [[ 1, 2 ], 2, [ 3, 4 ]];
When Not To Use It
You can turn this rule off if you are not concerned with the consistency of spacing between array brackets.
Related Rules
- [space-in-parens](space-in-parens.md)
- [object-curly-spacing](object-curly-spacing.md)
- [computed-property-spacing](computed-property-spacing.md) Source: http://eslint.org/docs/rules/
Unnecessarily quoted property 'bottle_neck' found. Open
associations: { 'bottle_neck': 'BottleneckEvent', 'project': 'ContainerProjectPerformance' },
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require quotes around object literal property names (quote-props)
Object literal property names can be defined in two ways: using literals or using strings. For example, these two objects are equivalent:
var object1 = {
property: true
};
var object2 = {
"property": true
};
In many cases, it doesn't matter if you choose to use an identifier instead of a string or vice-versa. Even so, you might decide to enforce a consistent style in your code.
There are, however, some occasions when you must use quotes:
- If you are using an ECMAScript 3 JavaScript engine (such as IE8) and you want to use a keyword (such as
if
) as a property name. This restriction was removed in ECMAScript 5. - You want to use a non-identifier character in your property name, such as having a property with a space like
"one two"
.
Another example where quotes do matter is when using numeric literals as property keys:
var object = {
1e2: 1,
100: 2
};
This may look alright at first sight, but this code in fact throws a syntax error in ECMAScript 5 strict mode. This happens because 1e2
and 100
are coerced into strings before getting used as the property name. Both String(1e2)
and String(100)
happen to be equal to "100"
, which causes the "Duplicate data property in object literal not allowed in strict mode" error. Issues like that can be tricky to debug, so some prefer to require quotes around all property names.
Rule Details
This rule requires quotes around object literal property names.
Options
This rule has two options, a string option and an object option.
String option:
-
"always"
(default) requires quotes around all object literal property names -
"as-needed"
disallows quotes around object literal property names that are not strictly required -
"consistent"
enforces a consistent quote style; in a given object, either all of the properties should be quoted, or none of the properties should be quoted -
"consistent-as-needed"
requires quotes around all object literal property names if any name strictly requires quotes, otherwise disallows quotes around object property names
Object option:
-
"keywords": true
requires quotes around language keywords used as object property names (only applies when usingas-needed
orconsistent-as-needed
) -
"unnecessary": true
(default) disallows quotes around object literal property names that are not strictly required (only applies when usingas-needed
) -
"unnecessary": false
allows quotes around object literal property names that are not strictly required (only applies when usingas-needed
) -
"numbers": true
requires quotes around numbers used as object property names (only applies when usingas-needed
)
always
Examples of incorrect code for this rule with the default "always"
option:
/*eslint quote-props: ["error", "always"]*/
var object = {
foo: "bar",
baz: 42,
"qux-lorem": true
};
Examples of correct code for this rule with the default "always"
option:
/*eslint quote-props: ["error", "always"]*/
/*eslint-env es6*/
var object1 = {
"foo": "bar",
"baz": 42,
"qux-lorem": true
};
var object2 = {
'foo': 'bar',
'baz': 42,
'qux-lorem': true
};
var object3 = {
foo() {
return;
}
};
as-needed
Examples of incorrect code for this rule with the "as-needed"
option:
/*eslint quote-props: ["error", "as-needed"]*/
var object = {
"a": 0,
"0": 0,
"true": 0,
"null": 0
};
Examples of correct code for this rule with the "as-needed"
option:
/*eslint quote-props: ["error", "as-needed"]*/
/*eslint-env es6*/
var object1 = {
"a-b": 0,
"0x0": 0,
"1e2": 0
};
var object2 = {
foo: 'bar',
baz: 42,
true: 0,
0: 0,
'qux-lorem': true
};
var object3 = {
foo() {
return;
}
};
consistent
Examples of incorrect code for this rule with the "consistent"
option:
/*eslint quote-props: ["error", "consistent"]*/
var object1 = {
foo: "bar",
"baz": 42,
"qux-lorem": true
};
var object2 = {
'foo': 'bar',
baz: 42
};
Examples of correct code for this rule with the "consistent"
option:
/*eslint quote-props: ["error", "consistent"]*/
var object1 = {
"foo": "bar",
"baz": 42,
"qux-lorem": true
};
var object2 = {
'foo': 'bar',
'baz': 42
};
var object3 = {
foo: 'bar',
baz: 42
};
consistent-as-needed
Examples of incorrect code for this rule with the "consistent-as-needed"
option:
/*eslint quote-props: ["error", "consistent-as-needed"]*/
var object1 = {
foo: "bar",
"baz": 42,
"qux-lorem": true
};
var object2 = {
'foo': 'bar',
'baz': 42
};
Examples of correct code for this rule with the "consistent-as-needed"
option:
/*eslint quote-props: ["error", "consistent-as-needed"]*/
var object1 = {
"foo": "bar",
"baz": 42,
"qux-lorem": true
};
var object2 = {
foo: 'bar',
baz: 42
};
keywords
Examples of additional incorrect code for this rule with the "as-needed", { "keywords": true }
options:
/*eslint quote-props: ["error", "as-needed", { "keywords": true }]*/
var x = {
while: 1,
volatile: "foo"
};
Examples of additional incorrect code for this rule with the "consistent-as-needed", { "keywords": true }
options:
/*eslint quote-props: ["error", "consistent-as-needed", { "keywords": true }]*/
var x = {
"prop": 1,
"bar": "foo"
};
unnecessary
Examples of additional correct code for this rule with the "as-needed", { "unnecessary": false }
options:
/*eslint quote-props: ["error", "as-needed", { "keywords": true, "unnecessary": false }]*/
var x = {
"while": 1,
"foo": "bar" // Would normally have caused a warning
};
numbers
Examples of additional incorrect code for this rule with the "as-needed", { "numbers": true }
options:
/*eslint quote-props: ["error", "as-needed", { "numbers": true }]*/
var x = {
100: 1
}
When Not To Use It
If you don't care if property names are consistently wrapped in quotes or not, and you don't target legacy ES3 environments, turn this rule off.
Further Reading
There should be no space before ']'. Open
methods: [ 'method' ],
- Read upRead up
- Create a ticketCreate a ticket
- Exclude checks
Disallow or enforce spaces inside of brackets (array-bracket-spacing)
A number of style guides require or disallow spaces between array brackets and other tokens. This rule applies to both array literals and destructuring assignments (ECMAScript 6).
/*eslint-env es6*/
var arr = [ 'foo', 'bar' ];
var [ x, y ] = z;
var arr = ['foo', 'bar'];
var [x,y] = z;
Rule Details
This rule enforces consistent spacing inside array brackets.
Options
This rule has a string option:
-
"never"
(default) disallows spaces inside array brackets -
"always"
requires one or more spaces or newlines inside array brackets
This rule has an object option for exceptions to the "never"
option:
-
"singleValue": true
requires one or more spaces or newlines inside brackets of array literals that contain a single element -
"objectsInArrays": true
requires one or more spaces or newlines between brackets of array literals and braces of their object literal elements[ {
or} ]
-
"arraysInArrays": true
requires one or more spaces or newlines between brackets of array literals and brackets of their array literal elements[ [
or] ]
This rule has an object option for exceptions to the "always"
option:
-
"singleValue": false
disallows spaces inside brackets of array literals that contain a single element -
"objectsInArrays": false
disallows spaces between brackets of array literals and braces of their object literal elements[{
or}]
-
"arraysInArrays": false
disallows spaces between brackets of array literals and brackets of their array literal elements[[
or]]
This rule has built-in exceptions:
-
"never"
(and also the exceptions to the"always"
option) allows newlines inside array brackets, because this is a common pattern -
"always"
does not require spaces or newlines in empty array literals[]
never
Examples of incorrect code for this rule with the default "never"
option:
/*eslint array-bracket-spacing: ["error", "never"]*/
/*eslint-env es6*/
var arr = [ 'foo', 'bar' ];
var arr = ['foo', 'bar' ];
var arr = [ ['foo'], 'bar'];
var arr = [[ 'foo' ], 'bar'];
var arr = [ 'foo',
'bar'
];
var [ x, y ] = z;
var [ x,y ] = z;
var [ x, ...y ] = z;
var [ ,,x, ] = z;
Examples of correct code for this rule with the default "never"
option:
/*eslint array-bracket-spacing: ["error", "never"]*/
/*eslint-env es6*/
var arr = [];
var arr = ['foo', 'bar', 'baz'];
var arr = [['foo'], 'bar', 'baz'];
var arr = [
'foo',
'bar',
'baz'
];
var arr = ['foo',
'bar'
];
var arr = [
'foo',
'bar'];
var [x, y] = z;
var [x,y] = z;
var [x, ...y] = z;
var [,,x,] = z;
always
Examples of incorrect code for this rule with the "always"
option:
/*eslint array-bracket-spacing: ["error", "always"]*/
/*eslint-env es6*/
var arr = ['foo', 'bar'];
var arr = ['foo', 'bar' ];
var arr = [ ['foo'], 'bar' ];
var arr = ['foo',
'bar'
];
var arr = [
'foo',
'bar'];
var [x, y] = z;
var [x,y] = z;
var [x, ...y] = z;
var [,,x,] = z;
Examples of correct code for this rule with the "always"
option:
/*eslint array-bracket-spacing: ["error", "always"]*/
/*eslint-env es6*/
var arr = [];
var arr = [ 'foo', 'bar', 'baz' ];
var arr = [ [ 'foo' ], 'bar', 'baz' ];
var arr = [ 'foo',
'bar'
];
var arr = [
'foo',
'bar' ];
var arr = [
'foo',
'bar',
'baz'
];
var [ x, y ] = z;
var [ x,y ] = z;
var [ x, ...y ] = z;
var [ ,,x, ] = z;
singleValue
Examples of incorrect code for this rule with the "always", { "singleValue": false }
options:
/*eslint array-bracket-spacing: ["error", "always", { "singleValue": false }]*/
var foo = [ 'foo' ];
var foo = [ 'foo'];
var foo = ['foo' ];
var foo = [ 1 ];
var foo = [ 1];
var foo = [1 ];
var foo = [ [ 1, 2 ] ];
var foo = [ { 'foo': 'bar' } ];
Examples of correct code for this rule with the "always", { "singleValue": false }
options:
/*eslint array-bracket-spacing: ["error", "always", { "singleValue": false }]*/
var foo = ['foo'];
var foo = [1];
var foo = [[ 1, 1 ]];
var foo = [{ 'foo': 'bar' }];
objectsInArrays
Examples of incorrect code for this rule with the "always", { "objectsInArrays": false }
options:
/*eslint array-bracket-spacing: ["error", "always", { "objectsInArrays": false }]*/
var arr = [ { 'foo': 'bar' } ];
var arr = [ {
'foo': 'bar'
} ]
Examples of correct code for this rule with the "always", { "objectsInArrays": false }
options:
/*eslint array-bracket-spacing: ["error", "always", { "objectsInArrays": false }]*/
var arr = [{ 'foo': 'bar' }];
var arr = [{
'foo': 'bar'
}];
arraysInArrays
Examples of incorrect code for this rule with the "always", { "arraysInArrays": false }
options:
/*eslint array-bracket-spacing: ["error", "always", { "arraysInArrays": false }]*/
var arr = [ [ 1, 2 ], 2, 3, 4 ];
var arr = [ [ 1, 2 ], 2, [ 3, 4 ] ];
Examples of correct code for this rule with the "always", { "arraysInArrays": false }
options:
/*eslint array-bracket-spacing: ["error", "always", { "arraysInArrays": false }]*/
var arr = [[ 1, 2 ], 2, 3, 4 ];
var arr = [[ 1, 2 ], 2, [ 3, 4 ]];
When Not To Use It
You can turn this rule off if you are not concerned with the consistency of spacing between array brackets.
Related Rules
- [space-in-parens](space-in-parens.md)
- [object-curly-spacing](object-curly-spacing.md)
- [computed-property-spacing](computed-property-spacing.md) Source: http://eslint.org/docs/rules/
Unnecessarily quoted property 'this_is_a_string' found. Open
attributes: { 'this_is_a_string': 'string' },
- Read upRead up
- Create a ticketCreate a ticket
- Exclude checks
require quotes around object literal property names (quote-props)
Object literal property names can be defined in two ways: using literals or using strings. For example, these two objects are equivalent:
var object1 = {
property: true
};
var object2 = {
"property": true
};
In many cases, it doesn't matter if you choose to use an identifier instead of a string or vice-versa. Even so, you might decide to enforce a consistent style in your code.
There are, however, some occasions when you must use quotes:
- If you are using an ECMAScript 3 JavaScript engine (such as IE8) and you want to use a keyword (such as
if
) as a property name. This restriction was removed in ECMAScript 5. - You want to use a non-identifier character in your property name, such as having a property with a space like
"one two"
.
Another example where quotes do matter is when using numeric literals as property keys:
var object = {
1e2: 1,
100: 2
};
This may look alright at first sight, but this code in fact throws a syntax error in ECMAScript 5 strict mode. This happens because 1e2
and 100
are coerced into strings before getting used as the property name. Both String(1e2)
and String(100)
happen to be equal to "100"
, which causes the "Duplicate data property in object literal not allowed in strict mode" error. Issues like that can be tricky to debug, so some prefer to require quotes around all property names.
Rule Details
This rule requires quotes around object literal property names.
Options
This rule has two options, a string option and an object option.
String option:
-
"always"
(default) requires quotes around all object literal property names -
"as-needed"
disallows quotes around object literal property names that are not strictly required -
"consistent"
enforces a consistent quote style; in a given object, either all of the properties should be quoted, or none of the properties should be quoted -
"consistent-as-needed"
requires quotes around all object literal property names if any name strictly requires quotes, otherwise disallows quotes around object property names
Object option:
-
"keywords": true
requires quotes around language keywords used as object property names (only applies when usingas-needed
orconsistent-as-needed
) -
"unnecessary": true
(default) disallows quotes around object literal property names that are not strictly required (only applies when usingas-needed
) -
"unnecessary": false
allows quotes around object literal property names that are not strictly required (only applies when usingas-needed
) -
"numbers": true
requires quotes around numbers used as object property names (only applies when usingas-needed
)
always
Examples of incorrect code for this rule with the default "always"
option:
/*eslint quote-props: ["error", "always"]*/
var object = {
foo: "bar",
baz: 42,
"qux-lorem": true
};
Examples of correct code for this rule with the default "always"
option:
/*eslint quote-props: ["error", "always"]*/
/*eslint-env es6*/
var object1 = {
"foo": "bar",
"baz": 42,
"qux-lorem": true
};
var object2 = {
'foo': 'bar',
'baz': 42,
'qux-lorem': true
};
var object3 = {
foo() {
return;
}
};
as-needed
Examples of incorrect code for this rule with the "as-needed"
option:
/*eslint quote-props: ["error", "as-needed"]*/
var object = {
"a": 0,
"0": 0,
"true": 0,
"null": 0
};
Examples of correct code for this rule with the "as-needed"
option:
/*eslint quote-props: ["error", "as-needed"]*/
/*eslint-env es6*/
var object1 = {
"a-b": 0,
"0x0": 0,
"1e2": 0
};
var object2 = {
foo: 'bar',
baz: 42,
true: 0,
0: 0,
'qux-lorem': true
};
var object3 = {
foo() {
return;
}
};
consistent
Examples of incorrect code for this rule with the "consistent"
option:
/*eslint quote-props: ["error", "consistent"]*/
var object1 = {
foo: "bar",
"baz": 42,
"qux-lorem": true
};
var object2 = {
'foo': 'bar',
baz: 42
};
Examples of correct code for this rule with the "consistent"
option:
/*eslint quote-props: ["error", "consistent"]*/
var object1 = {
"foo": "bar",
"baz": 42,
"qux-lorem": true
};
var object2 = {
'foo': 'bar',
'baz': 42
};
var object3 = {
foo: 'bar',
baz: 42
};
consistent-as-needed
Examples of incorrect code for this rule with the "consistent-as-needed"
option:
/*eslint quote-props: ["error", "consistent-as-needed"]*/
var object1 = {
foo: "bar",
"baz": 42,
"qux-lorem": true
};
var object2 = {
'foo': 'bar',
'baz': 42
};
Examples of correct code for this rule with the "consistent-as-needed"
option:
/*eslint quote-props: ["error", "consistent-as-needed"]*/
var object1 = {
"foo": "bar",
"baz": 42,
"qux-lorem": true
};
var object2 = {
foo: 'bar',
baz: 42
};
keywords
Examples of additional incorrect code for this rule with the "as-needed", { "keywords": true }
options:
/*eslint quote-props: ["error", "as-needed", { "keywords": true }]*/
var x = {
while: 1,
volatile: "foo"
};
Examples of additional incorrect code for this rule with the "consistent-as-needed", { "keywords": true }
options:
/*eslint quote-props: ["error", "consistent-as-needed", { "keywords": true }]*/
var x = {
"prop": 1,
"bar": "foo"
};
unnecessary
Examples of additional correct code for this rule with the "as-needed", { "unnecessary": false }
options:
/*eslint quote-props: ["error", "as-needed", { "keywords": true, "unnecessary": false }]*/
var x = {
"while": 1,
"foo": "bar" // Would normally have caused a warning
};
numbers
Examples of additional incorrect code for this rule with the "as-needed", { "numbers": true }
options:
/*eslint quote-props: ["error", "as-needed", { "numbers": true }]*/
var x = {
100: 1
}
When Not To Use It
If you don't care if property names are consistently wrapped in quotes or not, and you don't target legacy ES3 environments, turn this rule off.
Further Reading
Unnecessarily quoted property 'project' found. Open
associations: { 'bottle_neck': 'BottleneckEvent', 'project': 'ContainerProjectPerformance' },
- Read upRead up
- Create a ticketCreate a ticket
- Exclude checks
require quotes around object literal property names (quote-props)
Object literal property names can be defined in two ways: using literals or using strings. For example, these two objects are equivalent:
var object1 = {
property: true
};
var object2 = {
"property": true
};
In many cases, it doesn't matter if you choose to use an identifier instead of a string or vice-versa. Even so, you might decide to enforce a consistent style in your code.
There are, however, some occasions when you must use quotes:
- If you are using an ECMAScript 3 JavaScript engine (such as IE8) and you want to use a keyword (such as
if
) as a property name. This restriction was removed in ECMAScript 5. - You want to use a non-identifier character in your property name, such as having a property with a space like
"one two"
.
Another example where quotes do matter is when using numeric literals as property keys:
var object = {
1e2: 1,
100: 2
};
This may look alright at first sight, but this code in fact throws a syntax error in ECMAScript 5 strict mode. This happens because 1e2
and 100
are coerced into strings before getting used as the property name. Both String(1e2)
and String(100)
happen to be equal to "100"
, which causes the "Duplicate data property in object literal not allowed in strict mode" error. Issues like that can be tricky to debug, so some prefer to require quotes around all property names.
Rule Details
This rule requires quotes around object literal property names.
Options
This rule has two options, a string option and an object option.
String option:
-
"always"
(default) requires quotes around all object literal property names -
"as-needed"
disallows quotes around object literal property names that are not strictly required -
"consistent"
enforces a consistent quote style; in a given object, either all of the properties should be quoted, or none of the properties should be quoted -
"consistent-as-needed"
requires quotes around all object literal property names if any name strictly requires quotes, otherwise disallows quotes around object property names
Object option:
-
"keywords": true
requires quotes around language keywords used as object property names (only applies when usingas-needed
orconsistent-as-needed
) -
"unnecessary": true
(default) disallows quotes around object literal property names that are not strictly required (only applies when usingas-needed
) -
"unnecessary": false
allows quotes around object literal property names that are not strictly required (only applies when usingas-needed
) -
"numbers": true
requires quotes around numbers used as object property names (only applies when usingas-needed
)
always
Examples of incorrect code for this rule with the default "always"
option:
/*eslint quote-props: ["error", "always"]*/
var object = {
foo: "bar",
baz: 42,
"qux-lorem": true
};
Examples of correct code for this rule with the default "always"
option:
/*eslint quote-props: ["error", "always"]*/
/*eslint-env es6*/
var object1 = {
"foo": "bar",
"baz": 42,
"qux-lorem": true
};
var object2 = {
'foo': 'bar',
'baz': 42,
'qux-lorem': true
};
var object3 = {
foo() {
return;
}
};
as-needed
Examples of incorrect code for this rule with the "as-needed"
option:
/*eslint quote-props: ["error", "as-needed"]*/
var object = {
"a": 0,
"0": 0,
"true": 0,
"null": 0
};
Examples of correct code for this rule with the "as-needed"
option:
/*eslint quote-props: ["error", "as-needed"]*/
/*eslint-env es6*/
var object1 = {
"a-b": 0,
"0x0": 0,
"1e2": 0
};
var object2 = {
foo: 'bar',
baz: 42,
true: 0,
0: 0,
'qux-lorem': true
};
var object3 = {
foo() {
return;
}
};
consistent
Examples of incorrect code for this rule with the "consistent"
option:
/*eslint quote-props: ["error", "consistent"]*/
var object1 = {
foo: "bar",
"baz": 42,
"qux-lorem": true
};
var object2 = {
'foo': 'bar',
baz: 42
};
Examples of correct code for this rule with the "consistent"
option:
/*eslint quote-props: ["error", "consistent"]*/
var object1 = {
"foo": "bar",
"baz": 42,
"qux-lorem": true
};
var object2 = {
'foo': 'bar',
'baz': 42
};
var object3 = {
foo: 'bar',
baz: 42
};
consistent-as-needed
Examples of incorrect code for this rule with the "consistent-as-needed"
option:
/*eslint quote-props: ["error", "consistent-as-needed"]*/
var object1 = {
foo: "bar",
"baz": 42,
"qux-lorem": true
};
var object2 = {
'foo': 'bar',
'baz': 42
};
Examples of correct code for this rule with the "consistent-as-needed"
option:
/*eslint quote-props: ["error", "consistent-as-needed"]*/
var object1 = {
"foo": "bar",
"baz": 42,
"qux-lorem": true
};
var object2 = {
foo: 'bar',
baz: 42
};
keywords
Examples of additional incorrect code for this rule with the "as-needed", { "keywords": true }
options:
/*eslint quote-props: ["error", "as-needed", { "keywords": true }]*/
var x = {
while: 1,
volatile: "foo"
};
Examples of additional incorrect code for this rule with the "consistent-as-needed", { "keywords": true }
options:
/*eslint quote-props: ["error", "consistent-as-needed", { "keywords": true }]*/
var x = {
"prop": 1,
"bar": "foo"
};
unnecessary
Examples of additional correct code for this rule with the "as-needed", { "unnecessary": false }
options:
/*eslint quote-props: ["error", "as-needed", { "keywords": true, "unnecessary": false }]*/
var x = {
"while": 1,
"foo": "bar" // Would normally have caused a warning
};
numbers
Examples of additional incorrect code for this rule with the "as-needed", { "numbers": true }
options:
/*eslint quote-props: ["error", "as-needed", { "numbers": true }]*/
var x = {
100: 1
}
When Not To Use It
If you don't care if property names are consistently wrapped in quotes or not, and you don't target legacy ES3 environments, turn this rule off.
Further Reading
Unnecessarily quoted property 'project' found. Open
associations: { 'bottle_neck': 'BottleneckEvent', 'project': 'ContainerProjectPerformance' },
- Read upRead up
- Create a ticketCreate a ticket
- Exclude checks
require quotes around object literal property names (quote-props)
Object literal property names can be defined in two ways: using literals or using strings. For example, these two objects are equivalent:
var object1 = {
property: true
};
var object2 = {
"property": true
};
In many cases, it doesn't matter if you choose to use an identifier instead of a string or vice-versa. Even so, you might decide to enforce a consistent style in your code.
There are, however, some occasions when you must use quotes:
- If you are using an ECMAScript 3 JavaScript engine (such as IE8) and you want to use a keyword (such as
if
) as a property name. This restriction was removed in ECMAScript 5. - You want to use a non-identifier character in your property name, such as having a property with a space like
"one two"
.
Another example where quotes do matter is when using numeric literals as property keys:
var object = {
1e2: 1,
100: 2
};
This may look alright at first sight, but this code in fact throws a syntax error in ECMAScript 5 strict mode. This happens because 1e2
and 100
are coerced into strings before getting used as the property name. Both String(1e2)
and String(100)
happen to be equal to "100"
, which causes the "Duplicate data property in object literal not allowed in strict mode" error. Issues like that can be tricky to debug, so some prefer to require quotes around all property names.
Rule Details
This rule requires quotes around object literal property names.
Options
This rule has two options, a string option and an object option.
String option:
-
"always"
(default) requires quotes around all object literal property names -
"as-needed"
disallows quotes around object literal property names that are not strictly required -
"consistent"
enforces a consistent quote style; in a given object, either all of the properties should be quoted, or none of the properties should be quoted -
"consistent-as-needed"
requires quotes around all object literal property names if any name strictly requires quotes, otherwise disallows quotes around object property names
Object option:
-
"keywords": true
requires quotes around language keywords used as object property names (only applies when usingas-needed
orconsistent-as-needed
) -
"unnecessary": true
(default) disallows quotes around object literal property names that are not strictly required (only applies when usingas-needed
) -
"unnecessary": false
allows quotes around object literal property names that are not strictly required (only applies when usingas-needed
) -
"numbers": true
requires quotes around numbers used as object property names (only applies when usingas-needed
)
always
Examples of incorrect code for this rule with the default "always"
option:
/*eslint quote-props: ["error", "always"]*/
var object = {
foo: "bar",
baz: 42,
"qux-lorem": true
};
Examples of correct code for this rule with the default "always"
option:
/*eslint quote-props: ["error", "always"]*/
/*eslint-env es6*/
var object1 = {
"foo": "bar",
"baz": 42,
"qux-lorem": true
};
var object2 = {
'foo': 'bar',
'baz': 42,
'qux-lorem': true
};
var object3 = {
foo() {
return;
}
};
as-needed
Examples of incorrect code for this rule with the "as-needed"
option:
/*eslint quote-props: ["error", "as-needed"]*/
var object = {
"a": 0,
"0": 0,
"true": 0,
"null": 0
};
Examples of correct code for this rule with the "as-needed"
option:
/*eslint quote-props: ["error", "as-needed"]*/
/*eslint-env es6*/
var object1 = {
"a-b": 0,
"0x0": 0,
"1e2": 0
};
var object2 = {
foo: 'bar',
baz: 42,
true: 0,
0: 0,
'qux-lorem': true
};
var object3 = {
foo() {
return;
}
};
consistent
Examples of incorrect code for this rule with the "consistent"
option:
/*eslint quote-props: ["error", "consistent"]*/
var object1 = {
foo: "bar",
"baz": 42,
"qux-lorem": true
};
var object2 = {
'foo': 'bar',
baz: 42
};
Examples of correct code for this rule with the "consistent"
option:
/*eslint quote-props: ["error", "consistent"]*/
var object1 = {
"foo": "bar",
"baz": 42,
"qux-lorem": true
};
var object2 = {
'foo': 'bar',
'baz': 42
};
var object3 = {
foo: 'bar',
baz: 42
};
consistent-as-needed
Examples of incorrect code for this rule with the "consistent-as-needed"
option:
/*eslint quote-props: ["error", "consistent-as-needed"]*/
var object1 = {
foo: "bar",
"baz": 42,
"qux-lorem": true
};
var object2 = {
'foo': 'bar',
'baz': 42
};
Examples of correct code for this rule with the "consistent-as-needed"
option:
/*eslint quote-props: ["error", "consistent-as-needed"]*/
var object1 = {
"foo": "bar",
"baz": 42,
"qux-lorem": true
};
var object2 = {
foo: 'bar',
baz: 42
};
keywords
Examples of additional incorrect code for this rule with the "as-needed", { "keywords": true }
options:
/*eslint quote-props: ["error", "as-needed", { "keywords": true }]*/
var x = {
while: 1,
volatile: "foo"
};
Examples of additional incorrect code for this rule with the "consistent-as-needed", { "keywords": true }
options:
/*eslint quote-props: ["error", "consistent-as-needed", { "keywords": true }]*/
var x = {
"prop": 1,
"bar": "foo"
};
unnecessary
Examples of additional correct code for this rule with the "as-needed", { "unnecessary": false }
options:
/*eslint quote-props: ["error", "as-needed", { "keywords": true, "unnecessary": false }]*/
var x = {
"while": 1,
"foo": "bar" // Would normally have caused a warning
};
numbers
Examples of additional incorrect code for this rule with the "as-needed", { "numbers": true }
options:
/*eslint quote-props: ["error", "as-needed", { "numbers": true }]*/
var x = {
100: 1
}
When Not To Use It
If you don't care if property names are consistently wrapped in quotes or not, and you don't target legacy ES3 environments, turn this rule off.
Further Reading
Unnecessarily quoted property 'bottle_neck' found. Open
associations: { 'bottle_neck': 'BottleneckEvent', 'project': 'ContainerProjectPerformance' },
- Read upRead up
- Create a ticketCreate a ticket
- Exclude checks
require quotes around object literal property names (quote-props)
Object literal property names can be defined in two ways: using literals or using strings. For example, these two objects are equivalent:
var object1 = {
property: true
};
var object2 = {
"property": true
};
In many cases, it doesn't matter if you choose to use an identifier instead of a string or vice-versa. Even so, you might decide to enforce a consistent style in your code.
There are, however, some occasions when you must use quotes:
- If you are using an ECMAScript 3 JavaScript engine (such as IE8) and you want to use a keyword (such as
if
) as a property name. This restriction was removed in ECMAScript 5. - You want to use a non-identifier character in your property name, such as having a property with a space like
"one two"
.
Another example where quotes do matter is when using numeric literals as property keys:
var object = {
1e2: 1,
100: 2
};
This may look alright at first sight, but this code in fact throws a syntax error in ECMAScript 5 strict mode. This happens because 1e2
and 100
are coerced into strings before getting used as the property name. Both String(1e2)
and String(100)
happen to be equal to "100"
, which causes the "Duplicate data property in object literal not allowed in strict mode" error. Issues like that can be tricky to debug, so some prefer to require quotes around all property names.
Rule Details
This rule requires quotes around object literal property names.
Options
This rule has two options, a string option and an object option.
String option:
-
"always"
(default) requires quotes around all object literal property names -
"as-needed"
disallows quotes around object literal property names that are not strictly required -
"consistent"
enforces a consistent quote style; in a given object, either all of the properties should be quoted, or none of the properties should be quoted -
"consistent-as-needed"
requires quotes around all object literal property names if any name strictly requires quotes, otherwise disallows quotes around object property names
Object option:
-
"keywords": true
requires quotes around language keywords used as object property names (only applies when usingas-needed
orconsistent-as-needed
) -
"unnecessary": true
(default) disallows quotes around object literal property names that are not strictly required (only applies when usingas-needed
) -
"unnecessary": false
allows quotes around object literal property names that are not strictly required (only applies when usingas-needed
) -
"numbers": true
requires quotes around numbers used as object property names (only applies when usingas-needed
)
always
Examples of incorrect code for this rule with the default "always"
option:
/*eslint quote-props: ["error", "always"]*/
var object = {
foo: "bar",
baz: 42,
"qux-lorem": true
};
Examples of correct code for this rule with the default "always"
option:
/*eslint quote-props: ["error", "always"]*/
/*eslint-env es6*/
var object1 = {
"foo": "bar",
"baz": 42,
"qux-lorem": true
};
var object2 = {
'foo': 'bar',
'baz': 42,
'qux-lorem': true
};
var object3 = {
foo() {
return;
}
};
as-needed
Examples of incorrect code for this rule with the "as-needed"
option:
/*eslint quote-props: ["error", "as-needed"]*/
var object = {
"a": 0,
"0": 0,
"true": 0,
"null": 0
};
Examples of correct code for this rule with the "as-needed"
option:
/*eslint quote-props: ["error", "as-needed"]*/
/*eslint-env es6*/
var object1 = {
"a-b": 0,
"0x0": 0,
"1e2": 0
};
var object2 = {
foo: 'bar',
baz: 42,
true: 0,
0: 0,
'qux-lorem': true
};
var object3 = {
foo() {
return;
}
};
consistent
Examples of incorrect code for this rule with the "consistent"
option:
/*eslint quote-props: ["error", "consistent"]*/
var object1 = {
foo: "bar",
"baz": 42,
"qux-lorem": true
};
var object2 = {
'foo': 'bar',
baz: 42
};
Examples of correct code for this rule with the "consistent"
option:
/*eslint quote-props: ["error", "consistent"]*/
var object1 = {
"foo": "bar",
"baz": 42,
"qux-lorem": true
};
var object2 = {
'foo': 'bar',
'baz': 42
};
var object3 = {
foo: 'bar',
baz: 42
};
consistent-as-needed
Examples of incorrect code for this rule with the "consistent-as-needed"
option:
/*eslint quote-props: ["error", "consistent-as-needed"]*/
var object1 = {
foo: "bar",
"baz": 42,
"qux-lorem": true
};
var object2 = {
'foo': 'bar',
'baz': 42
};
Examples of correct code for this rule with the "consistent-as-needed"
option:
/*eslint quote-props: ["error", "consistent-as-needed"]*/
var object1 = {
"foo": "bar",
"baz": 42,
"qux-lorem": true
};
var object2 = {
foo: 'bar',
baz: 42
};
keywords
Examples of additional incorrect code for this rule with the "as-needed", { "keywords": true }
options:
/*eslint quote-props: ["error", "as-needed", { "keywords": true }]*/
var x = {
while: 1,
volatile: "foo"
};
Examples of additional incorrect code for this rule with the "consistent-as-needed", { "keywords": true }
options:
/*eslint quote-props: ["error", "consistent-as-needed", { "keywords": true }]*/
var x = {
"prop": 1,
"bar": "foo"
};
unnecessary
Examples of additional correct code for this rule with the "as-needed", { "unnecessary": false }
options:
/*eslint quote-props: ["error", "as-needed", { "keywords": true, "unnecessary": false }]*/
var x = {
"while": 1,
"foo": "bar" // Would normally have caused a warning
};
numbers
Examples of additional incorrect code for this rule with the "as-needed", { "numbers": true }
options:
/*eslint quote-props: ["error", "as-needed", { "numbers": true }]*/
var x = {
100: 1
}
When Not To Use It
If you don't care if property names are consistently wrapped in quotes or not, and you don't target legacy ES3 environments, turn this rule off.
Further Reading
Unnecessarily quoted property 'this_is_a_string' found. Open
attributes: { 'this_is_a_string': 'string' },
- Read upRead up
- Create a ticketCreate a ticket
- Exclude checks
require quotes around object literal property names (quote-props)
Object literal property names can be defined in two ways: using literals or using strings. For example, these two objects are equivalent:
var object1 = {
property: true
};
var object2 = {
"property": true
};
In many cases, it doesn't matter if you choose to use an identifier instead of a string or vice-versa. Even so, you might decide to enforce a consistent style in your code.
There are, however, some occasions when you must use quotes:
- If you are using an ECMAScript 3 JavaScript engine (such as IE8) and you want to use a keyword (such as
if
) as a property name. This restriction was removed in ECMAScript 5. - You want to use a non-identifier character in your property name, such as having a property with a space like
"one two"
.
Another example where quotes do matter is when using numeric literals as property keys:
var object = {
1e2: 1,
100: 2
};
This may look alright at first sight, but this code in fact throws a syntax error in ECMAScript 5 strict mode. This happens because 1e2
and 100
are coerced into strings before getting used as the property name. Both String(1e2)
and String(100)
happen to be equal to "100"
, which causes the "Duplicate data property in object literal not allowed in strict mode" error. Issues like that can be tricky to debug, so some prefer to require quotes around all property names.
Rule Details
This rule requires quotes around object literal property names.
Options
This rule has two options, a string option and an object option.
String option:
-
"always"
(default) requires quotes around all object literal property names -
"as-needed"
disallows quotes around object literal property names that are not strictly required -
"consistent"
enforces a consistent quote style; in a given object, either all of the properties should be quoted, or none of the properties should be quoted -
"consistent-as-needed"
requires quotes around all object literal property names if any name strictly requires quotes, otherwise disallows quotes around object property names
Object option:
-
"keywords": true
requires quotes around language keywords used as object property names (only applies when usingas-needed
orconsistent-as-needed
) -
"unnecessary": true
(default) disallows quotes around object literal property names that are not strictly required (only applies when usingas-needed
) -
"unnecessary": false
allows quotes around object literal property names that are not strictly required (only applies when usingas-needed
) -
"numbers": true
requires quotes around numbers used as object property names (only applies when usingas-needed
)
always
Examples of incorrect code for this rule with the default "always"
option:
/*eslint quote-props: ["error", "always"]*/
var object = {
foo: "bar",
baz: 42,
"qux-lorem": true
};
Examples of correct code for this rule with the default "always"
option:
/*eslint quote-props: ["error", "always"]*/
/*eslint-env es6*/
var object1 = {
"foo": "bar",
"baz": 42,
"qux-lorem": true
};
var object2 = {
'foo': 'bar',
'baz': 42,
'qux-lorem': true
};
var object3 = {
foo() {
return;
}
};
as-needed
Examples of incorrect code for this rule with the "as-needed"
option:
/*eslint quote-props: ["error", "as-needed"]*/
var object = {
"a": 0,
"0": 0,
"true": 0,
"null": 0
};
Examples of correct code for this rule with the "as-needed"
option:
/*eslint quote-props: ["error", "as-needed"]*/
/*eslint-env es6*/
var object1 = {
"a-b": 0,
"0x0": 0,
"1e2": 0
};
var object2 = {
foo: 'bar',
baz: 42,
true: 0,
0: 0,
'qux-lorem': true
};
var object3 = {
foo() {
return;
}
};
consistent
Examples of incorrect code for this rule with the "consistent"
option:
/*eslint quote-props: ["error", "consistent"]*/
var object1 = {
foo: "bar",
"baz": 42,
"qux-lorem": true
};
var object2 = {
'foo': 'bar',
baz: 42
};
Examples of correct code for this rule with the "consistent"
option:
/*eslint quote-props: ["error", "consistent"]*/
var object1 = {
"foo": "bar",
"baz": 42,
"qux-lorem": true
};
var object2 = {
'foo': 'bar',
'baz': 42
};
var object3 = {
foo: 'bar',
baz: 42
};
consistent-as-needed
Examples of incorrect code for this rule with the "consistent-as-needed"
option:
/*eslint quote-props: ["error", "consistent-as-needed"]*/
var object1 = {
foo: "bar",
"baz": 42,
"qux-lorem": true
};
var object2 = {
'foo': 'bar',
'baz': 42
};
Examples of correct code for this rule with the "consistent-as-needed"
option:
/*eslint quote-props: ["error", "consistent-as-needed"]*/
var object1 = {
"foo": "bar",
"baz": 42,
"qux-lorem": true
};
var object2 = {
foo: 'bar',
baz: 42
};
keywords
Examples of additional incorrect code for this rule with the "as-needed", { "keywords": true }
options:
/*eslint quote-props: ["error", "as-needed", { "keywords": true }]*/
var x = {
while: 1,
volatile: "foo"
};
Examples of additional incorrect code for this rule with the "consistent-as-needed", { "keywords": true }
options:
/*eslint quote-props: ["error", "consistent-as-needed", { "keywords": true }]*/
var x = {
"prop": 1,
"bar": "foo"
};
unnecessary
Examples of additional correct code for this rule with the "as-needed", { "unnecessary": false }
options:
/*eslint quote-props: ["error", "as-needed", { "keywords": true, "unnecessary": false }]*/
var x = {
"while": 1,
"foo": "bar" // Would normally have caused a warning
};
numbers
Examples of additional incorrect code for this rule with the "as-needed", { "numbers": true }
options:
/*eslint quote-props: ["error", "as-needed", { "numbers": true }]*/
var x = {
100: 1
}
When Not To Use It
If you don't care if property names are consistently wrapped in quotes or not, and you don't target legacy ES3 environments, turn this rule off.
Further Reading
There should be no space after '['. Open
methods: [ 'method' ],
- Read upRead up
- Create a ticketCreate a ticket
- Exclude checks
Disallow or enforce spaces inside of brackets (array-bracket-spacing)
A number of style guides require or disallow spaces between array brackets and other tokens. This rule applies to both array literals and destructuring assignments (ECMAScript 6).
/*eslint-env es6*/
var arr = [ 'foo', 'bar' ];
var [ x, y ] = z;
var arr = ['foo', 'bar'];
var [x,y] = z;
Rule Details
This rule enforces consistent spacing inside array brackets.
Options
This rule has a string option:
-
"never"
(default) disallows spaces inside array brackets -
"always"
requires one or more spaces or newlines inside array brackets
This rule has an object option for exceptions to the "never"
option:
-
"singleValue": true
requires one or more spaces or newlines inside brackets of array literals that contain a single element -
"objectsInArrays": true
requires one or more spaces or newlines between brackets of array literals and braces of their object literal elements[ {
or} ]
-
"arraysInArrays": true
requires one or more spaces or newlines between brackets of array literals and brackets of their array literal elements[ [
or] ]
This rule has an object option for exceptions to the "always"
option:
-
"singleValue": false
disallows spaces inside brackets of array literals that contain a single element -
"objectsInArrays": false
disallows spaces between brackets of array literals and braces of their object literal elements[{
or}]
-
"arraysInArrays": false
disallows spaces between brackets of array literals and brackets of their array literal elements[[
or]]
This rule has built-in exceptions:
-
"never"
(and also the exceptions to the"always"
option) allows newlines inside array brackets, because this is a common pattern -
"always"
does not require spaces or newlines in empty array literals[]
never
Examples of incorrect code for this rule with the default "never"
option:
/*eslint array-bracket-spacing: ["error", "never"]*/
/*eslint-env es6*/
var arr = [ 'foo', 'bar' ];
var arr = ['foo', 'bar' ];
var arr = [ ['foo'], 'bar'];
var arr = [[ 'foo' ], 'bar'];
var arr = [ 'foo',
'bar'
];
var [ x, y ] = z;
var [ x,y ] = z;
var [ x, ...y ] = z;
var [ ,,x, ] = z;
Examples of correct code for this rule with the default "never"
option:
/*eslint array-bracket-spacing: ["error", "never"]*/
/*eslint-env es6*/
var arr = [];
var arr = ['foo', 'bar', 'baz'];
var arr = [['foo'], 'bar', 'baz'];
var arr = [
'foo',
'bar',
'baz'
];
var arr = ['foo',
'bar'
];
var arr = [
'foo',
'bar'];
var [x, y] = z;
var [x,y] = z;
var [x, ...y] = z;
var [,,x,] = z;
always
Examples of incorrect code for this rule with the "always"
option:
/*eslint array-bracket-spacing: ["error", "always"]*/
/*eslint-env es6*/
var arr = ['foo', 'bar'];
var arr = ['foo', 'bar' ];
var arr = [ ['foo'], 'bar' ];
var arr = ['foo',
'bar'
];
var arr = [
'foo',
'bar'];
var [x, y] = z;
var [x,y] = z;
var [x, ...y] = z;
var [,,x,] = z;
Examples of correct code for this rule with the "always"
option:
/*eslint array-bracket-spacing: ["error", "always"]*/
/*eslint-env es6*/
var arr = [];
var arr = [ 'foo', 'bar', 'baz' ];
var arr = [ [ 'foo' ], 'bar', 'baz' ];
var arr = [ 'foo',
'bar'
];
var arr = [
'foo',
'bar' ];
var arr = [
'foo',
'bar',
'baz'
];
var [ x, y ] = z;
var [ x,y ] = z;
var [ x, ...y ] = z;
var [ ,,x, ] = z;
singleValue
Examples of incorrect code for this rule with the "always", { "singleValue": false }
options:
/*eslint array-bracket-spacing: ["error", "always", { "singleValue": false }]*/
var foo = [ 'foo' ];
var foo = [ 'foo'];
var foo = ['foo' ];
var foo = [ 1 ];
var foo = [ 1];
var foo = [1 ];
var foo = [ [ 1, 2 ] ];
var foo = [ { 'foo': 'bar' } ];
Examples of correct code for this rule with the "always", { "singleValue": false }
options:
/*eslint array-bracket-spacing: ["error", "always", { "singleValue": false }]*/
var foo = ['foo'];
var foo = [1];
var foo = [[ 1, 1 ]];
var foo = [{ 'foo': 'bar' }];
objectsInArrays
Examples of incorrect code for this rule with the "always", { "objectsInArrays": false }
options:
/*eslint array-bracket-spacing: ["error", "always", { "objectsInArrays": false }]*/
var arr = [ { 'foo': 'bar' } ];
var arr = [ {
'foo': 'bar'
} ]
Examples of correct code for this rule with the "always", { "objectsInArrays": false }
options:
/*eslint array-bracket-spacing: ["error", "always", { "objectsInArrays": false }]*/
var arr = [{ 'foo': 'bar' }];
var arr = [{
'foo': 'bar'
}];
arraysInArrays
Examples of incorrect code for this rule with the "always", { "arraysInArrays": false }
options:
/*eslint array-bracket-spacing: ["error", "always", { "arraysInArrays": false }]*/
var arr = [ [ 1, 2 ], 2, 3, 4 ];
var arr = [ [ 1, 2 ], 2, [ 3, 4 ] ];
Examples of correct code for this rule with the "always", { "arraysInArrays": false }
options:
/*eslint array-bracket-spacing: ["error", "always", { "arraysInArrays": false }]*/
var arr = [[ 1, 2 ], 2, 3, 4 ];
var arr = [[ 1, 2 ], 2, [ 3, 4 ]];
When Not To Use It
You can turn this rule off if you are not concerned with the consistency of spacing between array brackets.
Related Rules
- [space-in-parens](space-in-parens.md)
- [object-curly-spacing](object-curly-spacing.md)
- [computed-property-spacing](computed-property-spacing.md) Source: http://eslint.org/docs/rules/
Trailing spaces not allowed. Open
},
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- Create a ticketCreate a ticket
- 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 -
"ignoreComments": false
(default) disallows trailing whitespace in comment blocks -
"ignoreComments": true
allows trailing whitespace in comment blocks
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;
//•••••
ignoreComments
Examples of correct code for this rule with the { "ignoreComments": true }
option:
/*eslint no-trailing-spaces: ["error", { "ignoreComments": true }]*/
//foo•
//•••••
/**
*•baz
*••
*•bar
*/
```Source: http://eslint.org/docs/rules/
There should be no space before ']'. Open
methods: [ 'method' ],
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- Exclude checks
Disallow or enforce spaces inside of brackets (array-bracket-spacing)
A number of style guides require or disallow spaces between array brackets and other tokens. This rule applies to both array literals and destructuring assignments (ECMAScript 6).
/*eslint-env es6*/
var arr = [ 'foo', 'bar' ];
var [ x, y ] = z;
var arr = ['foo', 'bar'];
var [x,y] = z;
Rule Details
This rule enforces consistent spacing inside array brackets.
Options
This rule has a string option:
-
"never"
(default) disallows spaces inside array brackets -
"always"
requires one or more spaces or newlines inside array brackets
This rule has an object option for exceptions to the "never"
option:
-
"singleValue": true
requires one or more spaces or newlines inside brackets of array literals that contain a single element -
"objectsInArrays": true
requires one or more spaces or newlines between brackets of array literals and braces of their object literal elements[ {
or} ]
-
"arraysInArrays": true
requires one or more spaces or newlines between brackets of array literals and brackets of their array literal elements[ [
or] ]
This rule has an object option for exceptions to the "always"
option:
-
"singleValue": false
disallows spaces inside brackets of array literals that contain a single element -
"objectsInArrays": false
disallows spaces between brackets of array literals and braces of their object literal elements[{
or}]
-
"arraysInArrays": false
disallows spaces between brackets of array literals and brackets of their array literal elements[[
or]]
This rule has built-in exceptions:
-
"never"
(and also the exceptions to the"always"
option) allows newlines inside array brackets, because this is a common pattern -
"always"
does not require spaces or newlines in empty array literals[]
never
Examples of incorrect code for this rule with the default "never"
option:
/*eslint array-bracket-spacing: ["error", "never"]*/
/*eslint-env es6*/
var arr = [ 'foo', 'bar' ];
var arr = ['foo', 'bar' ];
var arr = [ ['foo'], 'bar'];
var arr = [[ 'foo' ], 'bar'];
var arr = [ 'foo',
'bar'
];
var [ x, y ] = z;
var [ x,y ] = z;
var [ x, ...y ] = z;
var [ ,,x, ] = z;
Examples of correct code for this rule with the default "never"
option:
/*eslint array-bracket-spacing: ["error", "never"]*/
/*eslint-env es6*/
var arr = [];
var arr = ['foo', 'bar', 'baz'];
var arr = [['foo'], 'bar', 'baz'];
var arr = [
'foo',
'bar',
'baz'
];
var arr = ['foo',
'bar'
];
var arr = [
'foo',
'bar'];
var [x, y] = z;
var [x,y] = z;
var [x, ...y] = z;
var [,,x,] = z;
always
Examples of incorrect code for this rule with the "always"
option:
/*eslint array-bracket-spacing: ["error", "always"]*/
/*eslint-env es6*/
var arr = ['foo', 'bar'];
var arr = ['foo', 'bar' ];
var arr = [ ['foo'], 'bar' ];
var arr = ['foo',
'bar'
];
var arr = [
'foo',
'bar'];
var [x, y] = z;
var [x,y] = z;
var [x, ...y] = z;
var [,,x,] = z;
Examples of correct code for this rule with the "always"
option:
/*eslint array-bracket-spacing: ["error", "always"]*/
/*eslint-env es6*/
var arr = [];
var arr = [ 'foo', 'bar', 'baz' ];
var arr = [ [ 'foo' ], 'bar', 'baz' ];
var arr = [ 'foo',
'bar'
];
var arr = [
'foo',
'bar' ];
var arr = [
'foo',
'bar',
'baz'
];
var [ x, y ] = z;
var [ x,y ] = z;
var [ x, ...y ] = z;
var [ ,,x, ] = z;
singleValue
Examples of incorrect code for this rule with the "always", { "singleValue": false }
options:
/*eslint array-bracket-spacing: ["error", "always", { "singleValue": false }]*/
var foo = [ 'foo' ];
var foo = [ 'foo'];
var foo = ['foo' ];
var foo = [ 1 ];
var foo = [ 1];
var foo = [1 ];
var foo = [ [ 1, 2 ] ];
var foo = [ { 'foo': 'bar' } ];
Examples of correct code for this rule with the "always", { "singleValue": false }
options:
/*eslint array-bracket-spacing: ["error", "always", { "singleValue": false }]*/
var foo = ['foo'];
var foo = [1];
var foo = [[ 1, 1 ]];
var foo = [{ 'foo': 'bar' }];
objectsInArrays
Examples of incorrect code for this rule with the "always", { "objectsInArrays": false }
options:
/*eslint array-bracket-spacing: ["error", "always", { "objectsInArrays": false }]*/
var arr = [ { 'foo': 'bar' } ];
var arr = [ {
'foo': 'bar'
} ]
Examples of correct code for this rule with the "always", { "objectsInArrays": false }
options:
/*eslint array-bracket-spacing: ["error", "always", { "objectsInArrays": false }]*/
var arr = [{ 'foo': 'bar' }];
var arr = [{
'foo': 'bar'
}];
arraysInArrays
Examples of incorrect code for this rule with the "always", { "arraysInArrays": false }
options:
/*eslint array-bracket-spacing: ["error", "always", { "arraysInArrays": false }]*/
var arr = [ [ 1, 2 ], 2, 3, 4 ];
var arr = [ [ 1, 2 ], 2, [ 3, 4 ] ];
Examples of correct code for this rule with the "always", { "arraysInArrays": false }
options:
/*eslint array-bracket-spacing: ["error", "always", { "arraysInArrays": false }]*/
var arr = [[ 1, 2 ], 2, 3, 4 ];
var arr = [[ 1, 2 ], 2, [ 3, 4 ]];
When Not To Use It
You can turn this rule off if you are not concerned with the consistency of spacing between array brackets.
Related Rules
- [space-in-parens](space-in-parens.md)
- [object-curly-spacing](object-curly-spacing.md)
- [computed-property-spacing](computed-property-spacing.md) Source: http://eslint.org/docs/rules/