js/no-trailing-spaces

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.

Rule Details

This rule disallows trailing whitespace (spaces, tabs, and other Unicode whitespace characters) at the end of lines.

Examples of incorrect code for this rule:

::: incorrect

/*eslint no-trailing-spaces: "error"*/

var foo = 0;/* trailing whitespace */
var baz = 5;/* trailing whitespace */
/* trailing whitespace */

:::

Examples of correct code for this rule:

::: correct

/*eslint no-trailing-spaces: "error"*/

var foo = 0;
var baz = 5;

:::

Options

This rule has an object option:

• "skipBlankLines": false (default) disallows trailing whitespace on empty lines
• "skipBlankLines": true allows trailing whitespace on empty lines
• "ignoreComments": false (default) disallows trailing whitespace in comment blocks
• "ignoreComments": true allows trailing whitespace in comment blocks

skipBlankLines

Examples of correct code for this rule with the { "skipBlankLines": true } option:

::: correct

/*eslint no-trailing-spaces: ["error", { "skipBlankLines": true }]*/

var foo = 0;
var baz = 5;
// ↓ a line with whitespace only ↓

:::

ignoreComments

Examples of correct code for this rule with the { "ignoreComments": true } option:

::: correct

/*eslint no-trailing-spaces: ["error", { "ignoreComments": true }]*/

// ↓ these comments have trailing whitespace →
//
/**
 * baz
 *
 * bar
 */

:::