enforce placing object properties on separate lines (object-property-newline)

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

While formatting preferences are very personal, a number of style guides require that object properties be placed on separate lines for better readability.

Another argument in favor of this style is that it improves the readability of diffs when a property is changed:

// More readable
 var obj = {
     foo: "foo",
-    bar: "bar",
+    bar: "bazz",
     baz: "baz"
 };

// Less readable
-var obj = { foo: "foo", bar: "bar", baz: "baz" };
+var obj = { foo: "foo", bar: "bazz", baz: "baz" };

Rule Details

This rule aims to maintain consistency of newlines between object properties.

Examples of incorrect code for this rule:

/*eslint object-property-newline: "error"*/

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

var obj2 = {
    foo: "foo", bar: "bar", baz: "baz"
};

var obj3 = {
    foo: "foo", bar: "bar",
    baz: "baz"
};

Examples of correct code for this rule:

/*eslint object-property-newline: "error"*/

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

Options

This rule has an object option:

allowMultiplePropertiesPerLine

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

/*eslint object-property-newline: ["error", { "allowMultiplePropertiesPerLine": true }]*/

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

var obj2 = {
    foo: "foo", bar: "bar", baz: "baz"
};

When Not To Use It

You can turn this rule off if you are not concerned with the consistency of newlines between object properties.

Compatibility

Version

This rule was introduced in ESLint 2.10.0.

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