require-named-capture-group.md

Suggest using named capture group in regular expression (require-named-capture-group)

With the landing of ECMAScript 2018, named capture group can be used in regular expression, which can improve the readability.

const regex = /(?<year>[0-9]{4})/;

Rule Details

This rule is aimed at using named capture group instead of numbered capture group in regular expression.

Examples of incorrect code for this rule:

/*eslint require-named-capture-group: "error"*/

const foo = /(ba[rz])/;
const bar = new RegExp('(ba[rz])');
const baz = RegExp('(ba[rz])');

foo.exec('bar')[1]; // Retrieve the group result.

Examples of correct code for this rule:

/*eslint require-named-capture-group: "error"*/

const foo = /(?<id>ba[rz])/;
const bar = new RegExp('(?<id>ba[rz])');
const baz = RegExp('(?<id>ba[rz])');

foo.exec('bar').groups.id; // Retrieve the group result.

When Not To Use It

If you are targeting ECMAScript 2017 and/or older environments, you can disable this rule, because this ECMAScript feature is only supported in ECMAScript 2018 and/or newer environments.

Related Rules

• no-invalid-regexp