no-dupe-characters-character-class.md

pageClass	sidebarDepth	title	description	since
rule-details	0	regexp/no-dupe-characters-character-class	disallow duplicate characters in the RegExp character class	v0.1.0

regexp/no-dupe-characters-character-class

💼 This rule is enabled in the ✅ plugin:regexp/recommended config.

🔧 This rule is automatically fixable by the --fix CLI option.

disallow duplicate characters in the RegExp character class

Because multiple same character classes in regular expressions only one is useful, they might be typing mistakes.

var foo = /\\(\\)/;

📖 Rule Details

This rule disallows duplicate characters in the RegExp character class.

/* eslint regexp/no-dupe-characters-character-class: "error" */

/* ✓ GOOD */
var foo = /[\(\)]/;

var foo = /[a-z\s]/;

var foo = /[\w]/;

/* ✗ BAD */
var foo = /[\\(\\)]/;
//          ^^ ^^        "\\" are duplicated
var foo = /[a-z\\s]/;
//          ^^^  ^       "s" are duplicated
var foo = /[\w0-9]/;
//          ^^^^^        "0-9" are duplicated

🔧 Options

Nothing.

🚀 Version

This rule was introduced in eslint-plugin-regexp v0.1.0

🔍 Implementation

• Rule source
• Test source