@babel/runtime

What is @babel/runtime?

The @babel/runtime package is a library that includes Babel modular runtime helpers and a version of regenerator-runtime. It is used to avoid polluting the global scope and to reduce the size of the compiled output by deduplicating helper functions that are commonly used by Babel-transpiled code. It is particularly useful when building libraries or applications that need to be optimized for size and scope isolation.

What are @babel/runtime's main functionalities?

Modularized Helpers

This feature allows you to use Babel's helper functions in a modular way, without including them in every file that needs them, thus reducing redundancy and file size.

import _classCallCheck from '@babel/runtime/helpers/classCallCheck';

class MyClass {
  constructor() {
    _classCallCheck(this, MyClass);
    // class body
  }
}

Regenerator Runtime

Includes a version of the regenerator runtime to enable the use of async/await and generator functions in environments that do not natively support them.

import 'regenerator-runtime/runtime';

async function asyncCall() {
  await someAsyncFunction();
}

Other packages similar to @babel/runtime

core-js

Similar to @babel/runtime, core-js is a modular standard library for JavaScript, which includes polyfills for ECMAScript features. It is often used in conjunction with Babel to ensure that newer language features will work in older environments. It is more comprehensive than @babel/runtime but can lead to larger bundle sizes if not used carefully.

tslib

tslib is a runtime library for TypeScript that includes helper functions similar to those in @babel/runtime. It is used to support features from TypeScript such as async/await, spread operators, and others without duplicating code. It is specific to TypeScript, whereas @babel/runtime is used with Babel and can be used with JavaScript or TypeScript.

README

@babel/runtime

babel's modular runtime helpers

See our website @babel/runtime for more information.

Install

Using npm:

npm install --save @babel/runtime

or using yarn:

yarn add @babel/runtime

Changelog

v7.26.0 (2024-10-25)

:rocket: New Feature

• babel-core, babel-generator, babel-parser, babel-plugin-syntax-import-assertions, babel-plugin-syntax-import-attributes, babel-preset-env, babel-standalone, babel-types
  • #16850 Enable import attributes parsing by default (@nicolo-ribaudo)
• babel-core
  • #16862 feat: support async plugin's pre/post (@timofei-iatsenko)
• babel-compat-data, babel-plugin-proposal-regexp-modifiers, babel-plugin-transform-regexp-modifiers, babel-preset-env, babel-standalone
  • #16692 Add transform-regexp-modifiers to preset-env (@JLHwung)
• babel-parser
  • #16849 feat: add startIndex parser option (@DylanPiercey)
• babel-generator, babel-parser, babel-plugin-syntax-flow
  • #16841 Always enable parsing of Flow enums (@nicolo-ribaudo)
• babel-helpers, babel-preset-typescript, babel-runtime-corejs3
  • #16794 Support import() in rewriteImportExtensions (@liuxingbaoyu)
• babel-generator, babel-parser
  • #16708 Add experimental format-preserving mode to @babel/generator (@nicolo-ribaudo)

:bug: Bug Fix

• babel-core
  • #16928 Workaround Node.js bug for parallel loading of TLA modules (@nicolo-ribaudo)
  • #16926 Fix loading of modules with TLA in Node.js 23 (@nicolo-ribaudo)

:nail_care: Polish

• babel-plugin-proposal-json-modules, babel-plugin-transform-json-modules, babel-standalone
  • #16924 Rename proposal-json-modules to transform-json-modules (@nicolo-ribaudo)

:house: Internal

• babel-code-frame, babel-highlight
  • #16896 Inline @babel/highlight in @babel/code-frame (@nicolo-ribaudo)
• babel-generator, babel-parser, babel-types
  • #16732 Add kind to TSModuleDeclaration (@liuxingbaoyu)

:running_woman: Performance

• babel-helper-module-transforms, babel-plugin-transform-modules-commonjs
  • #16882 perf: Improve module transforms (@liuxingbaoyu)