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function-call-spacing ​

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:

js
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:

  • "never" (default) disallows space between the function name and the opening parenthesis.
  • "always" requires space between the function name and the opening parenthesis.

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:

js
/* eslint @stylistic/function-call-spacing: ["error", "never"] */

fn
();
fn
();
incorrect

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

js
/* eslint @stylistic/function-call-spacing: ["error", "never"] */

fn();
correct

always ​

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

js
/* eslint @stylistic/function-call-spacing: ["error", "always"] */

fn
();
fn
();
incorrect

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

js
/* eslint @stylistic/function-call-spacing: ["error", "always"] */

fn ();
correct

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:

js
/* eslint @stylistic/function-call-spacing: ["error", "always", { "allowNewlines": true }] */

fn
();
incorrect

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

js
/* eslint @stylistic/function-call-spacing: ["error", "always", { "allowNewlines": true }] */

fn (); // Newlines are never required.

fn
();
correct

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 ​

Released under the MIT License.