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 Examples of **incorrect** code for this rule:
  24
  25 ```js
  26 /*eslint switch-colon-spacing: "error"*/
  27
  28 switch (a) {
  29     case 0 :break;
  30     default :foo();
  31 }
  32 ```
  33
  34 Examples of **correct** code for this rule:
  35
  36 ```js
  37 /*eslint switch-colon-spacing: "error"*/
  38
  39 switch (a) {
  40     case 0: foo(); break;
  41     case 1:
  42         bar();
  43         break;
  44     default:
  45         baz();
  46         break;
  47 }
  48 ```
  49
  50 Examples of **incorrect** code for this rule with `{"after": false, "before": true}` option:
  51
  52 ```js
  53 /*eslint switch-colon-spacing: ["error", {"after": false, "before": true}]*/
  54
  55 switch (a) {
  56     case 0: break;
  57     default: foo();
  58 }
  59 ```
  60
  61 Examples of **correct** code for this rule with `{"after": false, "before": true}` option:
  62
  63 ```js
  64 /*eslint switch-colon-spacing: ["error", {"after": false, "before": true}]*/
  65
  66 switch (a) {
  67     case 0 :foo(); break;
  68     case 1 :
  69         bar();
  70         break;
  71     default :
  72         baz();
  73         break;
  74 }
  75 ```
  76
  77 ## When Not To Use It
  78
  79 If you don't want to notify spacing around colons of switch statements, then it's safe to disable this rule.