@babel/plugin-transform-unicode-regex

What is @babel/plugin-transform-unicode-regex?

The @babel/plugin-transform-unicode-regex package is a plugin for Babel, a JavaScript compiler, that transforms Unicode regular expressions into equivalent ES5 syntax. This is particularly useful for ensuring compatibility with older environments that do not support Unicode property escapes in regular expressions.

What are @babel/plugin-transform-unicode-regex's main functionalities?

Transform Unicode Regular Expressions

This plugin transforms Unicode regular expressions like the one above into an ES5-compatible syntax. The 'u' flag in the regular expression indicates that it's using Unicode mode, which is not supported in older JavaScript environments. The plugin will convert this to a form that can be understood by these environments.

const regex = /\p{Script=Greek}/u;

Other packages similar to @babel/plugin-transform-unicode-regex

regexpu-core

regexpu-core is a package that also compiles Unicode regular expressions to ES5. It is similar to @babel/plugin-transform-unicode-regex but can be used independently of Babel. It provides a low-level API for transforming regular expressions and is used by Babel itself.

babel-plugin-transform-es2015-unicode-regex

This is a legacy Babel plugin that was used to transform Unicode regular expressions in ES2015 (ES6) code to be ES5-compatible. It has similar functionality to @babel/plugin-transform-unicode-regex but is specific to the ES2015 preset. It is now deprecated in favor of the unified @babel/preset-env.

README

@babel/plugin-transform-unicode-regex

Compile ES2015 unicode regex to ES5

Example

In

var string = "foo💩bar";
var match = string.match(/foo(.)bar/u);

Out

var string = "foo💩bar";
var match = string.match(/foo((?:[\0-\t\x0B\f\x0E-\u2027\u202A-\uD7FF\uE000-\uFFFF]|[\uD800-\uDBFF][\uDC00-\uDFFF]|[\uD800-\uDBFF](?![\uDC00-\uDFFF])|(?:[^\uD800-\uDBFF]|^)[\uDC00-\uDFFF]))bar/);

Installation

npm install --save-dev @babel/plugin-transform-unicode-regex

Usage

Via .babelrc (Recommended)

.babelrc

{
  "plugins": ["@babel/plugin-transform-unicode-regex"]
}

Via CLI

babel --plugins @babel/plugin-transform-unicode-regex script.js

Via Node API

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