arrow-spacing

Enforce consistent spacing before and after the arrow in arrow functions

This rule was deprecated in ESLint v8.53.0. Please use the corresponding rule in @stylistic/eslint-plugin-js.

This rule normalize style of spacing before/after an arrow function’s arrow(=>).

// { "before": true, "after": true }
(a) => {}

// { "before": false, "after": false }
(a)=>{}
1
2
3
4
5

Rule Details

This rule takes an object argument with before and after properties, each with a Boolean value.

The default configuration is { "before": true, "after": true }.

true means there should be one or more spaces and false means no spaces.

Examples of incorrect code for this rule with the default { "before": true, "after": true } option:

/*eslint arrow-spacing: "error"*/

()=> {};
() =>{};
(a)=> {};
(a) =>{};
a =>a;
a=> a;
()=> {'\n'};
() =>{'\n'};
1
2
3
4
5
6
7
8
9
10

Examples of correct code for this rule with the default { "before": true, "after": true } option:

/*eslint arrow-spacing: "error"*/

() => {};
(a) => {};
a => a;
() => {'\n'};
1
2
3
4
5
6

Examples of incorrect code for this rule with the { "before": false, "after": false } option:

/*eslint arrow-spacing: ["error", { "before": false, "after": false }]*/

() =>{};
(a) => {};
()=> {'\n'};
1
2
3
4
5

Examples of correct code for this rule with the { "before": false, "after": false } option:

/*eslint arrow-spacing: ["error", { "before": false, "after": false }]*/

()=>{};
(a)=>{};
()=>{'\n'};
1
2
3
4
5

Examples of incorrect code for this rule with the { "before": false, "after": true } option:

/*eslint arrow-spacing: ["error", { "before": false, "after": true }]*/

() =>{};
(a) => {};
()=>{'\n'};
1
2
3
4
5

Examples of correct code for this rule with the { "before": false, "after": true } option:

/*eslint arrow-spacing: ["error", { "before": false, "after": true }]*/

()=> {};
(a)=> {};
()=> {'\n'};
1
2
3
4
5

Version

This rule was introduced in ESLint v1.0.0-rc-1.

Resources

• Rule source
• Tests source