eslint/docs/rules/switch-colon-spacing.md

   1 # Enforce spacing around colons of switch statements (switch-colon-spacing)
   2
   3 Spacing around colons improves readability of `case`/`default` clauses.
   4
   5 ## Rule Details
   6
   7 This rule controls spacing around colons of `case` and `default` clauses in `switch` statements.
   8 This rule does the check only if the consecutive tokens exist on the same line.
   9
  10 This rule has 2 options that are boolean value.
  11
  12 ```json
  13 {
  14     "switch-colon-spacing": ["error", {"after": true, "before": false}]
  15 }
  16 ```
  17
  18 - `"after": true` (Default) requires one or more spaces after colons.
  19 - `"after": false` disallows spaces after colons.
  20 - `"before": true` requires one or more spaces before colons.
  21 - `"before": false` (Default) disallows before colons.
  22
  23
  24 Examples of **incorrect** code for this rule:
  25
  26 ```js
  27 /*eslint switch-colon-spacing: "error"*/
  28
  29 switch (a) {
  30     case 0 :break;
  31     default :foo();
  32 }
  33 ```
  34
  35 Examples of **correct** code for this rule:
  36
  37 ```js
  38 /*eslint switch-colon-spacing: "error"*/
  39
  40 switch (a) {
  41     case 0: foo(); break;
  42     case 1:
  43         bar();
  44         break;
  45     default:
  46         baz();
  47         break;
  48 }
  49 ```
  50
  51 Examples of **incorrect** code for this rule with `{"after": false, "before": true}` option:
  52
  53 ```js
  54 /*eslint switch-colon-spacing: ["error", {"after": false, "before": true}]*/
  55
  56 switch (a) {
  57     case 0: break;
  58     default: foo();
  59 }
  60 ```
  61
  62 Examples of **correct** code for this rule with `{"after": false, "before": true}` option:
  63
  64 ```js
  65 /*eslint switch-colon-spacing: ["error", {"after": false, "before": true}]*/
  66
  67 switch (a) {
  68     case 0 :foo(); break;
  69     case 1 :
  70         bar();
  71         break;
  72     default :
  73         baz();
  74         break;
  75 }
  76 ```
  77
  78 ## When Not To Use It
  79
  80 If you don't want to notify spacing around colons of switch statements, then it's safe to disable this rule.