eslint/docs/src/rules/no-trailing-spaces.md

   1 ---
   2 title: no-trailing-spaces
   3 layout: doc
   4 rule_type: layout
   5 ---
   6
   7
   8
   9 Sometimes in the course of editing files, you can end up with extra whitespace at the end of lines. These whitespace differences can be picked up by source control systems and flagged as diffs, causing frustration for developers. While this extra whitespace causes no functional issues, many code conventions require that trailing spaces be removed before check-in.
  10
  11 ## Rule Details
  12
  13 This rule disallows trailing whitespace (spaces, tabs, and other Unicode whitespace characters) at the end of lines.
  14
  15 Examples of **incorrect** code for this rule:
  16
  17 ::: incorrect
  18
  19 ```js
  20 /*eslint no-trailing-spaces: "error"*/
  21
  22 var foo = 0;//•••••
  23 var baz = 5;//••
  24 //•••••
  25 ```
  26
  27 :::
  28
  29 Examples of **correct** code for this rule:
  30
  31 ::: correct
  32
  33 ```js
  34 /*eslint no-trailing-spaces: "error"*/
  35
  36 var foo = 0;
  37 var baz = 5;
  38 ```
  39
  40 :::
  41
  42 ## Options
  43
  44 This rule has an object option:
  45
  46 * `"skipBlankLines": false` (default) disallows trailing whitespace on empty lines
  47 * `"skipBlankLines": true` allows trailing whitespace on empty lines
  48 * `"ignoreComments": false` (default) disallows trailing whitespace in comment blocks
  49 * `"ignoreComments": true` allows trailing whitespace in comment blocks
  50
  51 ### skipBlankLines
  52
  53 Examples of **correct** code for this rule with the `{ "skipBlankLines": true }` option:
  54
  55 ::: correct
  56
  57 ```js
  58 /*eslint no-trailing-spaces: ["error", { "skipBlankLines": true }]*/
  59
  60 var foo = 0;
  61 var baz = 5;
  62 //•••••
  63 ```
  64
  65 :::
  66
  67 ### ignoreComments
  68
  69 Examples of **correct** code for this rule with the `{ "ignoreComments": true }` option:
  70
  71 ::: correct
  72
  73 ```js
  74 /*eslint no-trailing-spaces: ["error", { "ignoreComments": true }]*/
  75
  76 //foo•
  77 //•••••
  78 /**
  79  *•baz
  80  *••
  81  *•bar
  82  */
  83 ```
  84
  85 :::