require or disallow spacing between function identifiers and their invocations (func-call-spacing)

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

When calling a function, developers may insert optional whitespace between the function’s name and the parentheses that invoke it. The following pairs of function calls are equivalent:

alert('Hello');
alert ('Hello');

console.log(42);
console.log (42);

new Date();
new Date ();

Rule Details

This rule requires or disallows spaces between the function name and the opening parenthesis that calls it.

options

This rule has a string option:

Further, in "always" mode, a second object option is available that contains a single boolean allowNewlines property.

never

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

/*eslint func-call-spacing: ["error", "never"]*/

fn ();

fn
();

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

/*eslint func-call-spacing: ["error", "never"]*/

fn();

always

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

/*eslint func-call-spacing: ["error", "always"]*/

fn();

fn
();

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

/*eslint func-call-spacing: ["error", "always"]*/

fn ();

allowNewlines

By default, "always" does not allow newlines. To permit newlines when in "always" mode, set the allowNewlines option to true. Newlines are never required.

Examples of incorrect code for this rule with allowNewlines option enabled:

/*eslint func-call-spacing: ["error", "always", { "allowNewlines": true }]*/

fn();

Examples of correct code for this rule with the allowNewlines option enabled:

/*eslint func-call-spacing: ["error", "always", { "allowNewlines": true }]*/

fn (); // Newlines are never required.

fn
();

When Not To Use It

This rule can safely be turned off if your project does not care about enforcing a consistent style for spacing within function calls.

Compatibility

Version

This rule was introduced in ESLint 3.3.0.

Resources


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