#no-invalid-regexp

#Configuration

import { defineConfig, js } from '@rslint/core';

export default defineConfig([
  js.configs.recommended,
  {
    rules: {
      'no-invalid-regexp': 'error',
    },
  },
]);

#Rule Details

Disallows invalid regular expression strings in RegExp constructors. This rule validates patterns and flags passed to new RegExp(pattern, flags) and RegExp(pattern, flags) when the arguments are string literals.

Valid flags are: d, g, i, m, s, u, v, y.

Examples of incorrect code for this rule:

RegExp('.', 'z'); // invalid flag 'z'
new RegExp('.', 'aa'); // duplicate flag 'a'
RegExp('.', 'uv'); // 'u' and 'v' flags are mutually exclusive
RegExp('['); // unterminated character class
RegExp('('); // unterminated group
new RegExp('\\'); // trailing backslash

Examples of correct code for this rule:

RegExp('.');
new RegExp('.', 'im');
new RegExp('.', 'gmi');
new RegExp(pattern, 'g'); // non-literal pattern, skipped
new RegExp('.', flags); // non-literal flags, skipped

#Options

#allowConstructorFlags

An array or string of additional flags to allow in RegExp constructors. For example, to allow the a and z flags:

{ "allowConstructorFlags": "az" }

#Known Limitations

The following ECMAScript regex features are not yet fully supported in pattern validation:

• Unicode property long names (\p{Letter}) and Script= syntax (\p{Script=Latin})
• v-flag set notation ([A--B], [A&&B], [A--[0-9]])
• Surrogate pair named capture groups ((?<\ud835\udc9c>.))
• Invalid escape detection in unicode mode (\a with u flag)
• v-flag specific parsing ([[] with v flag)
• Duplicate named capture groups outside alternatives ((?<k>a)(?<k>b))
• Inline modifier validation ((?ii:foo), (?-:foo), (?-u:foo))

Flag validation (invalid flags, duplicate flags, u/v conflict) and allowConstructorFlags are fully aligned with ESLint.

#Original Documentation

• ESLint no-invalid-regexp