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 @stylistic/js/indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the default options:
/*eslint @stylistic/js/indent: "error"*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
This rule has an object option:
"ignoredNodes"
can be used to disable indentation checking for any AST node. This accepts an array of selectors. If an AST node is matched by any of the selectors, the indentation of tokens which are direct children of that node will be ignored. This can be used as an escape hatch to relax the rule if you disagree with the indentation that it enforces for a particular syntactic pattern."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. It can also be"first"
, indicating all the declarators should be aligned with the first declarator."outerIIFEBody"
(default: 1) enforces indentation level for file-level IIFEs. This can also be set to"off"
to disable checking for file-level IIFEs."MemberExpression"
(default: 1) enforces indentation level for multi-line property chains. This can also be set to"off"
to disable checking for MemberExpression indentation."FunctionDeclaration"
takes an object to define rules for function declarations.parameters
(default: 1) 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. This can also be set to"off"
to disable checking for FunctionDeclaration parameters.body
(default: 1) enforces indentation level for the body of a function declaration.
"FunctionExpression"
takes an object to define rules for function expressions.parameters
(default: 1) 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. This can also be set to"off"
to disable checking for FunctionExpression parameters.body
(default: 1) enforces indentation level for the body of a function expression.
"StaticBlock"
takes an object to define rules for class static blocks.body
(default: 1) enforces indentation level for the body of a class static block.
"CallExpression"
takes an object to define rules for function call expressions.arguments
(default: 1) 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. This can also be set to"off"
to disable checking for CallExpression arguments.
"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. This can also be set to"off"
to disable checking for array elements."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. This can also be set to"off"
to disable checking for object properties."ImportDeclaration"
(default: 1) enforces indentation level for import statements. It can be set to the string"first"
, indicating that all imported members from a module should be aligned with the first member in the list. This can also be set to"off"
to disable checking for imported module members."flatTernaryExpressions": true
(false
by default) requires no indentation for ternary expressions which are nested in other ternary expressions."offsetTernaryExpressions": true
(false
by default) requires indentation for values of ternary expressions."ignoreComments"
(default: false) can be used when comments do not need to be aligned with nodes on the previous or next line."tabLength"
(default: 4) when using tabbed indentation, the indentation used to calculate the insertion value of the template string
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 @stylistic/js/indent: ["error", "tab"]*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
Examples of correct code for this rule with the "tab"
option:
/*eslint @stylistic/js/indent: ["error", "tab"]*/
if (a) {
b=c;
function foo(d) {
e=f;
}
}
ignoredNodes
The following configuration ignores the indentation of ConditionalExpression
("ternary expression") nodes:
Examples of correct code for this rule with the 4, { "ignoredNodes": ["ConditionalExpression"] }
option:
/*eslint @stylistic/js/indent: ["error", 4, { "ignoredNodes": ["ConditionalExpression"] }]*/
var a = foo
? bar
: baz;
var a = foo
? bar
: baz;
The following configuration ignores indentation in the body of IIFEs.
Examples of correct code for this rule with the 4, { "ignoredNodes": ["CallExpression > FunctionExpression.callee > BlockStatement.body"] }
option:
/*eslint @stylistic/js/indent: ["error", 4, { "ignoredNodes": ["CallExpression > FunctionExpression.callee > BlockStatement.body"] }]*/
(function() {
foo();
bar();
})();
All AST node types can be found at ESTree specification. You can use AST Explorer with the espree parser to examine AST tree of a code snippet.
SwitchCase
Examples of incorrect code for this rule with the 2, { "SwitchCase": 1 }
options:
/*eslint @stylistic/js/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 @stylistic/js/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 @stylistic/js/indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let d,
e,
f;
const g = 1,
h = 2,
i = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 1 }
options:
/*eslint @stylistic/js/indent: ["error", 2, { "VariableDeclarator": 1 }]*/
/*eslint-env es6*/
var a,
b,
c;
let d,
e,
f;
const g = 1,
h = 2,
i = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": 2 }
options:
/*eslint @stylistic/js/indent: ["error", 2, { "VariableDeclarator": 2 }]*/
/*eslint-env es6*/
var a,
b,
c;
let d,
e,
f;
const g = 1,
h = 2,
i = 3;
Examples of incorrect code for this rule with the 2, { "VariableDeclarator": "first" }
options:
/*eslint @stylistic/js/indent: ["error", 2, { "VariableDeclarator": "first" }]*/
/*eslint-env es6*/
var a,
b,
c;
let d,
e,
f;
const g = 1,
h = 2,
i = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": "first" }
options:
/*eslint @stylistic/js/indent: ["error", 2, { "VariableDeclarator": "first" }]*/
/*eslint-env es6*/
var a,
b,
c;
let d,
e,
f;
const g = 1,
h = 2,
i = 3;
Examples of correct code for this rule with the 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }
options:
/*eslint @stylistic/js/indent: ["error", 2, { "VariableDeclarator": { "var": 2, "let": 2, "const": 3 } }]*/
/*eslint-env es6*/
var a,
b,
c;
let d,
e,
f;
const g = 1,
h = 2,
i = 3;
outerIIFEBody
Examples of incorrect code for this rule with the options 2, { "outerIIFEBody": 0 }
:
/*eslint @stylistic/js/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 @stylistic/js/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": "off" }
:
/*eslint @stylistic/js/indent: ["error", 2, { "outerIIFEBody": "off" }]*/
(function() {
function foo(x) {
return x + 1;
}
})();
(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 @stylistic/js/indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz()
Examples of correct code for this rule with the 2, { "MemberExpression": 1 }
option:
/*eslint @stylistic/js/indent: ["error", 2, { "MemberExpression": 1 }]*/
foo
.bar
.baz();
FunctionDeclaration
Examples of incorrect code for this rule with the 2, { "FunctionDeclaration": {"body": 1, "parameters": 2} }
option:
/*eslint @stylistic/js/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 @stylistic/js/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 @stylistic/js/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 @stylistic/js/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 @stylistic/js/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 @stylistic/js/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 @stylistic/js/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 @stylistic/js/indent: ["error", 2, {"FunctionExpression": {"parameters": "first"}}]*/
var foo = function(bar, baz,
qux, boop) {
qux();
}
StaticBlock
Examples of incorrect code for this rule with the 2, { "StaticBlock": {"body": 1} }
option:
/*eslint @stylistic/js/indent: ["error", 2, { "StaticBlock": {"body": 1} }]*/
class C {
static {
foo();
}
}
Examples of correct code for this rule with the 2, { "StaticBlock": {"body": 1} }
option:
/*eslint @stylistic/js/indent: ["error", 2, { "StaticBlock": {"body": 1} }]*/
class C {
static {
foo();
}
}
Examples of incorrect code for this rule with the 2, { "StaticBlock": {"body": 2} }
option:
/*eslint @stylistic/js/indent: ["error", 2, { "StaticBlock": {"body": 2} }]*/
class C {
static {
foo();
}
}
Examples of correct code for this rule with the 2, { "StaticBlock": {"body": 2} }
option:
/*eslint @stylistic/js/indent: ["error", 2, { "StaticBlock": {"body": 2} }]*/
class C {
static {
foo();
}
}
CallExpression
Examples of incorrect code for this rule with the 2, { "CallExpression": {"arguments": 1} }
option:
/*eslint @stylistic/js/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 @stylistic/js/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 @stylistic/js/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 @stylistic/js/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 @stylistic/js/indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": 1 }
option:
/*eslint @stylistic/js/indent: ["error", 2, { "ArrayExpression": 1 }]*/
var foo = [
bar,
baz,
qux
];
Examples of incorrect code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint @stylistic/js/indent: ["error", 2, {"ArrayExpression": "first"}]*/
var foo = [bar,
baz,
qux
];
Examples of correct code for this rule with the 2, { "ArrayExpression": "first" }
option:
/*eslint @stylistic/js/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 @stylistic/js/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 @stylistic/js/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 @stylistic/js/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 @stylistic/js/indent: ["error", 2, {"ObjectExpression": "first"}]*/
var foo = { bar: 1,
baz: 2 };
ImportDeclaration
Examples of correct code for this rule with the 4, { "ImportDeclaration": 1 }
option (the default):
/*eslint @stylistic/js/indent: ["error", 4, { "ImportDeclaration": 1 }]*/
import { foo,
bar,
baz,
} from 'qux';
/*eslint @stylistic/js/indent: ["error", 4, { "ImportDeclaration": 1 }]*/
import {
foo,
bar,
baz,
} from 'qux';
Examples of incorrect code for this rule with the 4, { "ImportDeclaration": "first" }
option:
/*eslint @stylistic/js/indent: ["error", 4, { "ImportDeclaration": "first" }]*/
import { foo,
bar,
baz,
} from 'qux';
Examples of correct code for this rule with the 4, { "ImportDeclaration": "first" }
option:
/*eslint @stylistic/js/indent: ["error", 4, { "ImportDeclaration": "first" }]*/
import { foo,
bar,
baz,
} from 'qux';
flatTernaryExpressions
Examples of incorrect code for this rule with the default 4, { "flatTernaryExpressions": false }
option:
/*eslint @stylistic/js/indent: ["error", 4, { "flatTernaryExpressions": false }]*/
var a =
foo ? bar :
baz ? qux :
boop;
Examples of correct code for this rule with the default 4, { "flatTernaryExpressions": false }
option:
/*eslint @stylistic/js/indent: ["error", 4, { "flatTernaryExpressions": false }]*/
var a =
foo ? bar :
baz ? qux :
boop;
Examples of incorrect code for this rule with the 4, { "flatTernaryExpressions": true }
option:
/*eslint @stylistic/js/indent: ["error", 4, { "flatTernaryExpressions": true }]*/
var a =
foo ? bar :
baz ? qux :
boop;
Examples of correct code for this rule with the 4, { "flatTernaryExpressions": true }
option:
/*eslint @stylistic/js/indent: ["error", 4, { "flatTernaryExpressions": true }]*/
var a =
foo ? bar :
baz ? qux :
boop;
offsetTernaryExpressions
Examples of incorrect code for this rule with the default 2, { "offsetTernaryExpressions": false }
option:
/*eslint @stylistic/js/indent: ["error", 2, { "offsetTernaryExpressions": false }]*/
condition
? () => {
return true
}
: () => {
false
}
Examples of correct code for this rule with the default 2, { "offsetTernaryExpressions": false }
option:
/*eslint @stylistic/js/indent: ["error", 2, { "offsetTernaryExpressions": false }]*/
condition
? () => {
return true
}
: condition2
? () => {
return true
}
: () => {
return false
}
Examples of incorrect code for this rule with the 2, { "offsetTernaryExpressions": true }
option:
/*eslint @stylistic/js/indent: ["error", 2, { "offsetTernaryExpressions": true }]*/
condition
? () => {
return true
}
: condition2
? () => {
return true
}
: () => {
return false
}
Examples of correct code for this rule with the 2, { "offsetTernaryExpressions": true }
option:
/*eslint @stylistic/js/indent: ["error", 2, { "offsetTernaryExpressions": true }]*/
condition
? () => {
return true
}
: condition2
? () => {
return true
}
: () => {
return false
}
ignoreComments
Examples of additional correct code for this rule with the 4, { "ignoreComments": true }
option:
/*eslint @stylistic/js/indent: ["error", 4, { "ignoreComments": true }] */
if (foo) {
doSomething();
// comment intentionally de-indented
doSomethingElse();
}
Compatibility
- JSHint:
indent
- JSCS: validateIndentation