eslint/docs/src/rules/func-call-spacing.md

   1 ---
   2 title: func-call-spacing
   3 layout: doc
   4 rule_type: layout
   5 related_rules:
   6 - no-spaced-func
   7 ---
   8
   9
  10
  11 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:
  12
  13 ```js
  14 alert('Hello');
  15 alert ('Hello');
  16
  17 console.log(42);
  18 console.log (42);
  19
  20 new Date();
  21 new Date ();
  22 ```
  23
  24 ## Rule Details
  25
  26 This rule requires or disallows spaces between the function name and the opening parenthesis that calls it.
  27
  28 ## Options
  29
  30 This rule has a string option:
  31
  32 * `"never"` (default) disallows space between the function name and the opening parenthesis.
  33 * `"always"` requires space between the function name and the opening parenthesis.
  34
  35 Further, in `"always"` mode, a second object option is available that contains a single boolean `allowNewlines` property.
  36
  37 ### never
  38
  39 Examples of **incorrect** code for this rule with the default `"never"` option:
  40
  41 ::: incorrect
  42
  43 ```js
  44 /*eslint func-call-spacing: ["error", "never"]*/
  45
  46 fn ();
  47
  48 fn
  49 ();
  50 ```
  51
  52 :::
  53
  54 Examples of **correct** code for this rule with the default `"never"` option:
  55
  56 ::: correct
  57
  58 ```js
  59 /*eslint func-call-spacing: ["error", "never"]*/
  60
  61 fn();
  62 ```
  63
  64 :::
  65
  66 ### always
  67
  68 Examples of **incorrect** code for this rule with the `"always"` option:
  69
  70 ::: incorrect
  71
  72 ```js
  73 /*eslint func-call-spacing: ["error", "always"]*/
  74
  75 fn();
  76
  77 fn
  78 ();
  79 ```
  80
  81 :::
  82
  83 Examples of **correct** code for this rule with the `"always"` option:
  84
  85 ::: correct
  86
  87 ```js
  88 /*eslint func-call-spacing: ["error", "always"]*/
  89
  90 fn ();
  91 ```
  92
  93 :::
  94
  95 #### allowNewlines
  96
  97 By default, `"always"` does not allow newlines. To permit newlines when in `"always"` mode, set the `allowNewlines` option to `true`. Newlines are never required.
  98
  99 Examples of **incorrect** code for this rule with `allowNewlines` option enabled:
 100
 101 ::: incorrect
 102
 103 ```js
 104 /*eslint func-call-spacing: ["error", "always", { "allowNewlines": true }]*/
 105
 106 fn();
 107 ```
 108
 109 :::
 110
 111 Examples of **correct** code for this rule with the `allowNewlines` option enabled:
 112
 113 ::: correct
 114
 115 ```js
 116 /*eslint func-call-spacing: ["error", "always", { "allowNewlines": true }]*/
 117
 118 fn (); // Newlines are never required.
 119
 120 fn
 121 ();
 122 ```
 123
 124 :::
 125
 126 ## When Not To Use It
 127
 128 This rule can safely be turned off if your project does not care about enforcing a consistent style for spacing within function calls.
 129
 130 ## Compatibility
 131
 132 * **JSCS**: [disallowSpacesInCallExpression](https://jscs-dev.github.io/rule/disallowSpacesInCallExpression)
 133 * **JSCS**: [requireSpacesInCallExpression](https://jscs-dev.github.io/rule/requireSpacesInCallExpression)