Introduction

eslint-plugin-regexp is ESLint plugin for finding RegExp mistakes and RegExp style guide violations.

📛 Features

This ESLint plugin provides linting rules relate to better ways to help you avoid problems when using RegExp.

Find the wrong usage of regular expressions, and their hints.
Enforces a consistent style of regular expressions.
Find hints for writing optimized regular expressions.

You can check on the Online DEMO.

📖 Documentation

💿 Installation

npm install --save-dev eslint eslint-plugin-regexp

Requirements

ESLint v6.0.0 and above

Node.js v8.10.0 and above

📖 Usage

Create .eslintrc.* file to configure rules. See also: http://eslint.org/docs/user-guide/configuring.

Example .eslintrc.js:

module.exports = {
  extends: [
    // add more generic rulesets here, such as:
    // 'eslint:recommended',
    'plugin:regexp/recommended'
  ],
  rules: {
    // override/add rules settings here, such as:
    // 'regexp/rule-name': 'error'
  }
}

Configuration

This plugin provides one config:

plugin:regexp/recommended ... This is the recommended configuration for this plugin. See lib/configs/recommended.ts for details.

✅ Rules

The --fix option on the command line automatically fixes problems reported by rules which have a wrench 🔧 below. The rules with the following star ⭐ are included in the plugin:regexp/recommended config.

Rule ID	Description
regexp/confusing-quantifier	disallow confusing quantifiers
regexp/control-character-escape	enforce consistent escaping of control characters	🔧
regexp/hexadecimal-escape	enforce consistent usage of hexadecimal escape	🔧
regexp/letter-case	enforce into your favorite case	🔧
regexp/match-any	enforce match any character style	⭐🔧
regexp/negation	enforce use of escapes on negation	🔧
regexp/no-assertion-capturing-group	disallow capturing group that captures assertions.	⭐
regexp/no-dupe-characters-character-class	disallow duplicate characters in the RegExp character class	⭐
regexp/no-dupe-disjunctions	disallow duplicate disjunctions
regexp/no-empty-alternative	disallow alternatives without elements
regexp/no-empty-group	disallow empty group	⭐
regexp/no-empty-lookarounds-assertion	disallow empty lookahead assertion or empty lookbehind assertion	⭐
regexp/no-escape-backspace	disallow escape backspace (`[\b]`)	⭐
regexp/no-invisible-character	disallow invisible raw character	⭐🔧
regexp/no-lazy-ends	disallow lazy quantifiers at the end of an expression
regexp/no-legacy-features	disallow legacy RegExp features
regexp/no-non-standard-flag	disallow non-standard flags
regexp/no-obscure-range	disallow obscure character ranges
regexp/no-octal	disallow octal escape sequence	⭐
regexp/no-optional-assertion	disallow optional assertions
regexp/no-potentially-useless-backreference	disallow backreferences that reference a group that might not be matched
regexp/no-standalone-backslash	disallow standalone backslashes (`\`)
regexp/no-trivially-nested-assertion	disallow trivially nested assertions	🔧
regexp/no-trivially-nested-quantifier	disallow nested quantifiers that can be rewritten as one quantifier	🔧
regexp/no-unused-capturing-group	disallow unused capturing group
regexp/no-useless-assertions	disallow assertions that are known to always accept (or reject)
regexp/no-useless-backreference	disallow useless backreferences in regular expressions	⭐
regexp/no-useless-character-class	disallow character class with one character	🔧
regexp/no-useless-dollar-replacements	disallow useless `$` replacements in replacement string
regexp/no-useless-escape	disallow unnecessary escape characters in RegExp
regexp/no-useless-exactly-quantifier	disallow unnecessary exactly quantifier	⭐
regexp/no-useless-flag	disallow unnecessary regex flags	🔧
regexp/no-useless-lazy	disallow unnecessarily non-greedy quantifiers	🔧
regexp/no-useless-non-capturing-group	disallow unnecessary Non-capturing group	🔧
regexp/no-useless-non-greedy	disallow unnecessarily non-greedy quantifiers	🔧
regexp/no-useless-range	disallow unnecessary range of characters by using a hyphen	🔧
regexp/no-useless-two-nums-quantifier	disallow unnecessary `{n,m}` quantifier	⭐🔧
regexp/optimal-lookaround-quantifier	disallow the alternatives of lookarounds that end with a non-constant quantifier
regexp/order-in-character-class	enforces elements order in character class	🔧
regexp/prefer-character-class	enforce using character class	🔧
regexp/prefer-d	enforce using `\d`	⭐🔧
regexp/prefer-escape-replacement-dollar-char	enforces escape of replacement `$` character (`$$`).
regexp/prefer-named-backreference	enforce using named backreferences	🔧
regexp/prefer-plus-quantifier	enforce using `+` quantifier	⭐🔧
regexp/prefer-predefined-assertion	prefer predefined assertion over equivalent lookarounds	🔧
regexp/prefer-quantifier	enforce using quantifier	🔧
regexp/prefer-question-quantifier	enforce using `?` quantifier	⭐🔧
regexp/prefer-range	enforce using character class range	🔧
regexp/prefer-regexp-exec	enforce that `RegExp#exec` is used instead of `String#match` if no global flag is provided
regexp/prefer-regexp-test	enforce that `RegExp#test` is used instead of `String#match` and `RegExp#exec`	🔧
regexp/prefer-star-quantifier	enforce using `*` quantifier	⭐🔧
regexp/prefer-t	enforce using `\t`	⭐🔧
regexp/prefer-unicode-codepoint-escapes	enforce use of unicode codepoint escapes	🔧
regexp/prefer-w	enforce using `\w`	⭐🔧
regexp/sort-flags	require regex flags to be sorted	🔧
regexp/unicode-escape	enforce consistent usage of unicode escape or unicode codepoint escape	🔧

⚙️ Settings

See Settings.

🍻 Contributing

Welcome contributing!

Please use GitHub's Issues/PRs.

Development Tools

npm test runs tests and measures coverage.
npm run update runs in order to update readme and recommended configuration.
npm run new [new rule name] runs to create the files needed for the new rule.
npm run docs:watch starts the website locally.

🔒 License

See the LICENSE file for license rights and limitations (MIT).

Eugeno / eslint-plugin-regexp