no-irregular-whitespace (Rules) - Eslint 中文开发手册
The "extends": "eslint:recommended" property in a configuration file enables this rule.
Invalid or irregular whitespace causes issues with ECMAScript 5 parsers and also makes code harder to debug in a similar nature to mixed tabs and spaces.
Various whitespace characters can be inputted by programmers by mistake for example from copying or keyboard shortcuts. Pressing Alt + Space on macOS adds in a non breaking space character for example.
Known issues these spaces cause:
Zero Width Space Is NOT considered a separator for tokens and is often parsed as an Unexpected token ILLEGAL Is NOT shown in modern browsers making code repository software expected to resolve the visualisationLine Separator Is NOT a valid character within JSON which would cause parse errors
Rule Details
This rule is aimed at catching invalid whitespace that is not a normal tab and space. Some of these characters may cause issues in modern browsers and others will be a debugging issue to spot.
This rule disallows the following characters except where the options allow:
u000B - Line Tabulation (v) - <VT> u000C - Form Feed (f) - <FF> u00A0 - No-Break Space - <NBSP> u0085 - Next Line u1680 - Ogham Space Mark u180E - Mongolian Vowel Separator - <MVS> ufeff - Zero Width No-Break Space - <BOM> u2000 - En Quad u2001 - Em Quad u2002 - En Space - <ENSP> u2003 - Em Space - <EMSP> u2004 - Tree-Per-Em u2005 - Four-Per-Em u2006 - Six-Per-Em u2007 - Figure Space u2008 - Punctuation Space - <PUNCSP> u2009 - Thin Space u200A - Hair Space u200B - Zero Width Space - <ZWSP> u2028 - Line Separator u2029 - Paragraph Separator u202F - Narrow No-Break Space u205f - Medium Mathematical Space u3000 - Ideographic Space
Options
This rule has an object option for exceptions:
"skipStrings": true (default) allows any whitespace characters in string literals"skipComments": true allows any whitespace characters in comments"skipRegExps": true allows any whitespace characters in regular expression literals"skipTemplates": true allows any whitespace characters in template literals
skipStrings
Examples of incorrect code for this rule with the default { "skipStrings": true } option:
/*eslint no-irregular-whitespace: "error"*/
function thing() /*<NBSP>*/{
return 'test';
}
function thing( /*<NBSP>*/){
return 'test';
}
function thing /*<NBSP>*/(){
return 'test';
}
function thing/*<MVS>*/(){
return 'test';
}
function thing() {
return 'test'; /*<ENSP>*/
}
function thing() {
return 'test'; /*<NBSP>*/
}
function thing() {
// Description <NBSP>: some descriptive text
}
/*
Description <NBSP>: some descriptive text
*/
function thing() {
return / <NBSP>regexp/;
}
/*eslint-env es6*/
function thing() {
return `template <NBSP>string`;
}
Examples of correct code for this rule with the default { "skipStrings": true } option:
/*eslint no-irregular-whitespace: "error"*/
function thing() {
return ' <NBSP>thing';
}
function thing() {
return '<ZWSP>thing';
}
function thing() {
return 'th <NBSP>ing';
}
skipComments
Examples of additional correct code for this rule with the { "skipComments": true } option:
/*eslint no-irregular-whitespace: ["error", { "skipComments": true }]*/
function thing() {
// Description <NBSP>: some descriptive text
}
/*
Description <NBSP>: some descriptive text
*/
skipRegExps
Examples of additional correct code for this rule with the { "skipRegExps": true } option:
/*eslint no-irregular-whitespace: ["error", { "skipRegExps": true }]*/
function thing() {
return / <NBSP>regexp/;
}
skipTemplates
Examples of additional correct code for this rule with the { "skipTemplates": true } option:
/*eslint no-irregular-whitespace: ["error", { "skipTemplates": true }]*/
/*eslint-env es6*/
function thing() {
return `template <NBSP>string`;
}
When Not To Use It
If you decide that you wish to use whitespace other than tabs and spaces outside of strings in your application.
Further Reading
ECMA whitespaceJSON whitespace issues
Version
This rule was introduced in ESLint 0.9.0.
Resources
Rule sourceDocumentation source
© JS Foundation and other contributors
Licensed under the MIT License.
https://eslint.org/docs/rules/no-irregular-whitespace
Eslint 中文开发手册