@babel/plugin-transform-named-capturing-groups-regex

info

This plugin is included in @babel/preset-env, in ES2018 NOTE: This plugin generates code that needs ES6 regular expressions functionalities. If you need to support older browsers, use either the runtime: false option or import a proper polyfill (e.g. core-js).

This plugin transforms regular expression literals to support named capturing groups. It does not patch the new RegExp constructor, since its arguments cannot be pre-transformed statically: to handle runtime behavior of functions/classes, you will need to use a polyfill instead.

Examples

In

JavaScript

var re = /(?<year>\d{4})-(?<month>\d{2})-(?<day>\d{2})/;

console.log(re.exec("1999-02-29").groups.year);

Out

JavaScript

var re = _wrapRegExp(/(\d{4})-(\d{2})-(\d{2})/, { year: 1, month: 2, day: 3 });

console.log(re.exec("1999-02-29").groups.year);

Installation

npm

npm install --save-dev @babel/plugin-transform-named-capturing-groups-regex

Yarn

yarn add --dev @babel/plugin-transform-named-capturing-groups-regex

pnpm

pnpm add --save-dev @babel/plugin-transform-named-capturing-groups-regex

Usage

With a configuration file (Recommended)

babel.config.json

{
  "plugins": ["@babel/plugin-transform-named-capturing-groups-regex"]
}

Via CLI

Shell

babel --plugins @babel/plugin-transform-named-capturing-groups-regex script.js

Via Node API

JavaScript

require("@babel/core").transformSync("code", {
  plugins: ["@babel/plugin-transform-named-capturing-groups-regex"],
});

Options

runtime

boolean, defaults to true

When this option is disabled, Babel doesn't wrap RegExps with the _wrapRegExp helper. The output only supports internal group references, and not runtime properties:

JavaScript

var stringRe = /(?<quote>"|').*?\k<quote>/;

stringRe.test("'foo'"); // "true", works
stringRe.exec("'foo'").groups.quote; // Error

tip

You can read more about configuring plugin options here