noUselessEscapeInRegex (JavaScript)

Language JavaScript (and super languages)

Summary

Rule available since: v1.9.0
Diagnostic Category: lint/complexity/noUselessEscapeInRegex
This rule is recommended, meaning it is enabled by default.
This rule has a safe fix.
The default severity of this rule is information.
Sources:
- Same as no-useless-escape

How to configure

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{
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  "linter": {
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    "rules": {
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      "complexity": {
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        "noUselessEscapeInRegex": "error"
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      }
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    }
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  }
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}

Description

Disallow unnecessary escape sequence in regular expression literals.

Escaping non-special characters in regular expression literals doesn’t have any effect. Hence, they may confuse a reader.

Examples

Invalid

1
/\a/;

code-block.js:1:2 lint/complexity/noUselessEscapeInRegex  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ The character doesn't need to be escaped.
  
  > 1 │ /\a/;
      │  ^^
    2 │ 
  
  ℹ Safe fix: Unescape the character.
  
    1 │ /\a/;
      │  -

1
/[\-]/;

code-block.js:1:3 lint/complexity/noUselessEscapeInRegex  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ The character doesn't need to be escaped.
  
  > 1 │ /[\-]/;
      │   ^^
    2 │ 
  
  ℹ The character should only be escaped if it appears in the middle of the character class or under the `v` flag.
  
  ℹ Safe fix: Unescape the character.
  
    1 │ /[\-]/;
      │   -

Valid

1
/\^\d\b/

1
/[\b]/

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/[\&]/v