useNamedCaptureGroup (JavaScript)

Language JavaScript (and super languages)

Summary

Rule available since: v2.4.5
Diagnostic Category: lint/style/useNamedCaptureGroup
This rule isn’t recommended, so you need to enable it.
This rule doesn’t have a fix.
The default severity of this rule is information.
Sources:
- Same as prefer-named-capture-group

How to configure

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{
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  "linter": {
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    "rules": {
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      "style": {
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        "useNamedCaptureGroup": "error"
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      }
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    }
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  }
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}

Description

Enforce using named capture groups in regular expression.

Numbered capture groups like (...) can be difficult to work with, as they are matched by their position and not by a descriptive name. Named capture groups ((?<name>...)) associate a descriptive name with each match, making the regular expression more readable and its intent clearer.

Examples

Invalid

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/(ba[rz])/;

code-block.js:1:2 lint/style/useNamedCaptureGroup ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Capture group is not named.
  
  > 1 │ /(ba[rz])/;
      │  ^
    2 │ 
  
  ℹ Named capture groups improve readability by associating a descriptive name with each match. Use (?<name>...) instead of (...).

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/([0-9]{4})/;

code-block.js:1:2 lint/style/useNamedCaptureGroup ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Capture group is not named.
  
  > 1 │ /([0-9]{4})/;
      │  ^
    2 │ 
  
  ℹ Named capture groups improve readability by associating a descriptive name with each match. Use (?<name>...) instead of (...).

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/(?:ab)(cd)/;

code-block.js:1:8 lint/style/useNamedCaptureGroup ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Capture group is not named.
  
  > 1 │ /(?:ab)(cd)/;
      │        ^
    2 │ 
  
  ℹ Named capture groups improve readability by associating a descriptive name with each match. Use (?<name>...) instead of (...).

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new RegExp("(foo)");

code-block.js:1:13 lint/style/useNamedCaptureGroup ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Capture group is not named.
  
  > 1 │ new RegExp("(foo)");
      │             ^
    2 │ 
  
  ℹ Named capture groups improve readability by associating a descriptive name with each match. Use (?<name>...) instead of (...).

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RegExp("(foo)");

code-block.js:1:9 lint/style/useNamedCaptureGroup ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Capture group is not named.
  
  > 1 │ RegExp("(foo)");
      │         ^
    2 │ 
  
  ℹ Named capture groups improve readability by associating a descriptive name with each match. Use (?<name>...) instead of (...).

Valid

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/(?<id>ba[rz])/;
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/(?:ba[rz])/;
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/ba[rz]/;
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/(?<year>[0-9]{4})-(?<month>[0-9]{2})/;
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new RegExp("(?<id>foo)");
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new RegExp(pattern);