eslint/docs/src/rules/no-mixed-spaces-and-tabs.md

   1 ---
   2 title: no-mixed-spaces-and-tabs
   3 rule_type: layout
   4 further_reading:
   5 - https://www.emacswiki.org/emacs/SmartTabs
   6 ---
   7
   8
   9
  10 Most code conventions require either tabs or spaces be used for indentation. As such, it's usually an error if a single line of code is indented with both tabs and spaces.
  11
  12 ## Rule Details
  13
  14 This rule disallows mixed spaces and tabs for indentation.
  15
  16 Examples of **incorrect** code for this rule:
  17
  18 ::: incorrect
  19
  20 ```js
  21 /*eslint no-mixed-spaces-and-tabs: "error"*/
  22
  23 function add(x, y) {
  24 // --->..return x + y;
  25
  26       return x + y;
  27 }
  28
  29 function main() {
  30 // --->var x = 5,
  31 // --->....y = 7;
  32
  33     var x = 5,
  34         y = 7;
  35 }
  36 ```
  37
  38 :::
  39
  40 Examples of **correct** code for this rule:
  41
  42 ::: correct
  43
  44 ```js
  45 /*eslint no-mixed-spaces-and-tabs: "error"*/
  46
  47 function add(x, y) {
  48 // --->return x + y;
  49     return x + y;
  50 }
  51 ```
  52
  53 :::
  54
  55 ## Options
  56
  57 This rule has a string option.
  58
  59 * `"smart-tabs"` allows mixed tabs and spaces when the spaces are used for alignment.
  60
  61 ### smart-tabs
  62
  63 Examples of **correct** code for this rule with the `"smart-tabs"` option:
  64
  65 ::: correct
  66
  67 ```js
  68 /*eslint no-mixed-spaces-and-tabs: ["error", "smart-tabs"]*/
  69
  70 function main() {
  71 // --->var x = 5,
  72 // --->....y = 7;
  73
  74     var x = 5,
  75         y = 7;
  76 }
  77 ```
  78
  79 :::