enforce line breaks between array elements (array-element-newline)

The --fix option on the command line can automatically fix some of the problems reported by this rule.

A number of style guides require or disallow line breaks between array elements.

Rule Details

This rule enforces line breaks between array elements.

Options

This rule has either a string option:

Or an object option (Requires line breaks if any of properties is satisfied. Otherwise, disallows line breaks):

always

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

/*eslint array-element-newline: ["error", "always"]*/

var c = [1, 2];
var d = [1, 2, 3];
var e = [
    function foo() {
        dosomething();
    }, function bar() {
        dosomething();
    }
];

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

/*eslint array-element-newline: ["error", "always"]*/

var a = [];
var b = [1];
var c = [1,
    2];
var d = [1,
    2,
    3];
var e = [
    function foo() {
        dosomething();
    },
    function bar() {
        dosomething();
    }
];

never

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

/*eslint array-element-newline: ["error", "never"]*/

var c = [
    1,
    2
];
var d = [
    1,
    2,
    3
];
var e = [
    function foo() {
        dosomething();
    },
    function bar() {
        dosomething();
    }
];

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

/*eslint array-element-newline: ["error", "never"]*/

var a = [];
var b = [1];
var c = [1, 2];
var d = [1, 2, 3];
var e = [
    function foo() {
        dosomething();
    }, function bar() {
        dosomething();
    }
];

multiline

Examples of incorrect code for this rule with the { "multiline": true } option:

/*eslint array-element-newline: ["error", { "multiline": true }]*/

var d = [1,
    2, 3];
var e = [
    function foo() {
        dosomething();
    }, function bar() {
        dosomething();
    }
];

Examples of correct code for this rule with the { "multiline": true } option:

/*eslint array-element-newline: ["error", { "multiline": true }]*/

var a = [];
var b = [1];
var c = [1, 2];
var d = [1, 2, 3];
var e = [
    function foo() {
        dosomething();
    },
    function bar() {
        dosomething();
    }
];

minItems

Examples of incorrect code for this rule with the { "minItems": 3 } option:

/*eslint array-element-newline: ["error", { "minItems": 3 }]*/

var c = [1,
    2];
var d = [1, 2, 3];
var e = [
    function foo() {
        dosomething();
    },
    function bar() {
        dosomething();
    }
];

Examples of correct code for this rule with the { "minItems": 3 } option:

/*eslint array-element-newline: ["error", { "minItems": 3 }]*/

var a = [];
var b = [1];
var c = [1, 2];
var d = [1,
    2,
    3];
var e = [
    function foo() {
        dosomething();
    }, function bar() {
        dosomething();
    }
];

multiline and minItems

Examples of incorrect code for this rule with the { "multiline": true, "minItems": 3 } options:

/*eslint array-element-newline: ["error", { "multiline": true, "minItems": 3 }]*/

var c = [1,
2];
var d = [1, 2, 3];
var e = [
    function foo() {
        dosomething();
    }, function bar() {
        dosomething();
    }
];

Examples of correct code for this rule with the { "multiline": true, "minItems": 3 } options:

/*eslint array-element-newline: ["error", { "multiline": true, "minItems": 3 }]*/

var a = [];
var b = [1];
var c = [1, 2];
var d = [1,
    2,
    3];
var e = [
    function foo() {
        dosomething();
    },
    function bar() {
        dosomething();
    }
];

When Not To Use It

If you don’t want to enforce linebreaks between array elements, don’t enable this rule.

Compatibility

Version

This rule was introduced in ESLint 4.0.0-rc.0.

Resources