#no-regex-spaces

#Configuration

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

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

#Rule Details

Disallow multiple spaces in regular expressions. Two or more consecutive space characters are hard to count by eye; an explicit {n} quantifier expresses the same pattern unambiguously. The rule applies to both regex literals and the RegExp / new RegExp constructors (skipped when RegExp is shadowed in the enclosing scope or when the flags argument cannot be statically determined). Consecutive spaces inside character classes ([...]) are intentionally allowed and not reported.

Examples of incorrect code for this rule:

var re = /foo   bar/;
var re = new RegExp('foo   bar');

Examples of correct code for this rule:

var re = /foo {3}bar/;
var re = new RegExp('foo {3}bar');
var re = /[  ]/;

#Autofix

When the parsed pattern and the raw source text agree (typically any regex literal, and RegExp / new RegExp calls whose pattern string contains no escape sequences), the rule rewrites into {n}. When the pattern contains escape sequences that differ from the raw source (e.g. new RegExp('\\d ')), the rule reports but does not autofix — the index into the parsed pattern would not map cleanly back to source positions.

#Differences from ESLint

• Constructor patterns using capture names or Unicode properties newer than the bundled TypeScript parser's Unicode data can be skipped.
• For a constructor pattern with a negated v class where a range is followed by a string-valued operand, rslint skips a report that ESLint may emit because JavaScript rejects the pattern.

#Original Documentation

• ESLint: no-regex-spaces
• Source code