object-curly-spacing.md

enforce consistent spacing inside braces (object-curly-spacing)

While formatting preferences are very personal, a number of style guides require or disallow spaces between curly braces in the following situations:

// simple object literals
var obj = { foo: "bar" };

// nested object literals
var obj = { foo: { zoo: "bar" } };

// destructuring assignment (EcmaScript 6)
var { x, y } = y;

// import/export declarations (EcmaScript 6)
import { foo } from "bar";
export { foo };

Rule Details

This rule enforces consistent spacing inside braces of object literals, destructuring assignments, and import/export specifiers.

Options

This rule has two options, a string option and an object option.

String option:

• "never" (default) disallows spacing inside of braces
• "always" requires spacing inside of braces (except {})

Object option:

• "arraysInObjects": true requires spacing inside of braces of objects beginning and/or ending with an array element (applies when the first option is set to never)
• "arraysInObjects": false disallows spacing inside of braces of objects beginning and/or ending with an array element (applies when the first option is set to always)
• "objectsInObjects": true requires spacing inside of braces of objects beginning and/or ending with an object element (applies when the first option is set to never)
• "objectsInObjects": false disallows spacing inside of braces of objects beginning and/or ending with an object element (applies when the first option is set to always)
• "import": true requires spacing inside of braces of beginning and/or ending with an import declaration (applies when the first option is set to never)
• "import": false disallows spacing inside of braces of beginning and/or ending with an import declaration (applies when the first option is set to always)
• "export": true requires spacing inside of braces of beginning and/or ending with an export declaration (applies when the first option is set to never)
• "export": false disallows spacing inside of braces of beginning and/or ending with an export declaration (applies when the first option is set to always)
• "multiline": true requires additional line breaking inside of multiline braces of beginning and/or ending with all blocks that support spacing
• "multiline": false disallows additional line breaking inside of multiline braces of beginning and/or ending with all blocks that support spacing

never

Examples of incorrect code for this rule with the default "never" option:

/*eslint object-curly-spacing: ["error", "never"]*/

var obj = { 'foo': 'bar' };
var obj = {'foo': 'bar' };
var obj = { baz: {'foo': 'qux'}, bar};
var obj = {baz: { 'foo': 'qux'}, bar};
var {x } = y;
import { foo } from 'bar';

Examples of correct code for this rule with the default "never" option:

/*eslint object-curly-spacing: ["error", "never"]*/

var obj = {'foo': 'bar'};
var obj = {'foo': {'bar': 'baz'}, 'qux': 'quxx'};
var obj = {
  'foo': 'bar'
};
var obj = {'foo': 'bar'
};
var obj = {
  'foo':'bar'};
var obj = {};
var {x} = y;
import {foo} from 'bar';

always

Examples of incorrect code for this rule with the "always" option:

/*eslint object-curly-spacing: ["error", "always"]*/

var obj = {'foo': 'bar'};
var obj = {'foo': 'bar' };
var obj = { baz: {'foo': 'qux'}, bar};
var obj = {baz: { 'foo': 'qux' }, bar};
var obj = {'foo': 'bar'
};
var obj = {
  'foo':'bar'};
var {x} = y;
import {foo } from 'bar';

Examples of correct code for this rule with the "always" option:

/*eslint object-curly-spacing: ["error", "always"]*/

var obj = {};
var obj = { 'foo': 'bar' };
var obj = { 'foo': { 'bar': 'baz' }, 'qux': 'quxx' };
var obj = {
  'foo': 'bar'
};
var { x } = y;
import { foo } from 'bar';

arraysInObjects

Examples of additional correct code for this rule with the "never", { "arraysInObjects": true } options:

/*eslint object-curly-spacing: ["error", "never", { "arraysInObjects": true }]*/

var obj = {"foo": [ 1, 2 ] };
var obj = {"foo": [ "baz", "bar" ] };

Examples of additional correct code for this rule with the "always", { "arraysInObjects": false } options:

/*eslint object-curly-spacing: ["error", "always", { "arraysInObjects": false }]*/

var obj = { "foo": [ 1, 2 ]};
var obj = { "foo": [ "baz", "bar" ]};

objectsInObjects

Examples of additional correct code for this rule with the "never", { "objectsInObjects": true } options:

/*eslint object-curly-spacing: ["error", "never", { "objectsInObjects": true }]*/

var obj = {"foo": {"baz": 1, "bar": 2} };

Examples of additional correct code for this rule with the "always", { "objectsInObjects": false } options:

/*eslint object-curly-spacing: ["error", "always", { "objectsInObjects": false }]*/

var obj = { "foo": { "baz": 1, "bar": 2 }};

import

Examples of additional correct code for this rule with the "never", { "import": true } options:

/*eslint object-curly-spacing: ["error", "never", { "import": true }]*/

import { foo } from 'bar';

Examples of additional correct code for this rule with the "always", { "import": false } options:

/*eslint object-curly-spacing: ["error", "always", { "import": false }]*/

import {foo} from 'bar';

export

Examples of additional correct code for this rule with the "never", { "export": true } options:

/*eslint object-curly-spacing: ["error", "never", { "export": true }]*/

export { foo } from 'bar';

Examples of additional correct code for this rule with the "always", { "export": false } options:

/*eslint object-curly-spacing: ["error", "always", { "export": false }]*/

import {foo} from 'bar';

multiline

Examples of additional correct code for this rule with the "never", { "export": true, "multiline": true } options:

/*eslint object-curly-spacing: ["error", "never", { "export": true, "multiline": true }]*/

export {

  foo,
  bar

} from 'bar';

Examples of additional correct code for this rule with the "always", { "multiline": false } options:

/*eslint object-curly-spacing: ["error", "always", { "multiline": true }]*/

const a = {

  a: 1,
  b: 2

};

When Not To Use It

You can turn this rule off if you are not concerned with the consistency of spacing between curly braces.