ESLintDisallows multiple blank lines (no-multiple-empty-lines)
Some developers prefer to have multiple blank lines removed, while others feel that it helps improve readability. Whitespace is useful for separating logical sections of code, but excess whitespace takes up more of the screen.
Rule Details
This rule aims to reduce the scrolling required when reading through your code. It will warn when the maximum amount of empty lines has been exceeded.
Options
The second argument can be used to configure this rule:
maxsets the maximum number of consecutive blank lines.maxEOFcan be used to set a different number for the end of file. The last blank lines will then be treated differently. If omitted, themaxoption is applied everywhere.
For example, this sets the rule as an error (code is 2) with a maximum tolerated blank lines of 2 (for the whole file):
"no-multiple-empty-lines": [2, {"max": 2}]
While this tolerates three consecutive blank lines within the file, but only one at the end:
"no-multiple-empty-lines": [2, {"max": 3, "maxEOF": 1}]
Examples
The following patterns are considered problems:
/*eslint no-multiple-empty-lines: [2, {max: 2}]*/
var foo = 5;
/*error Multiple blank lines not allowed.*/
var bar = 3;
/*eslint no-multiple-empty-lines: [2, {max: 2, maxEOF: 1}]*/
var foo = 5;
/*error Too many blank lines at the end of file.*/
The following patterns are not considered problems:
/*eslint no-multiple-empty-lines: [2, {max: 2}]*/
var foo = 5;
var bar = 3;
/*eslint no-multiple-empty-lines: [2, {max: 4}]*/
var foo = 5;
var bar = 3;
/*eslint no-multiple-empty-lines: [2, {max: 2}]*/
var foo = 5;
// extra line
/*eslint no-multiple-empty-lines: [2, {max: 2, maxEOF: 10}]*/
var foo = 5;
// 10 extra lines
When Not To Use It
If you do not care about extra blank lines, turn this off.
Version
This rule was introduced in ESLint 0.9.0.