@babel/runtime-corejs3

What is @babel/runtime-corejs3?

The @babel/runtime-corejs3 package is a runtime library for Babel that includes polyfills for ECMAScript features using core-js version 3. It is used alongside Babel to enable the use of new JavaScript features in environments that do not natively support them. This package helps to avoid polluting the global scope and reduces the size of the compiled code by deduplicating helper functions.

What are @babel/runtime-corejs3's main functionalities?

Polyfilling ECMAScript features

This code imports polyfills for stable ECMAScript features and the regenerator runtime needed to use generators and async functions.

import 'core-js/stable';
import 'regenerator-runtime/runtime';

Usage of built-in methods

This code demonstrates how to use the map method from core-js through the runtime without polluting the global Array prototype.

import { map } from '@babel/runtime-corejs3/core-js-stable/instance/map';

let arr = [1, 2, 3];
let mapped = map.call(arr, x => x * x);

Usage of new syntax features

This code shows how to use the helpers provided by @babel/runtime-corejs3 to work with new syntax features like async functions and generators.

import _asyncToGenerator from '@babel/runtime-corejs3/helpers/asyncToGenerator';
import _regeneratorRuntime from '@babel/runtime-corejs3/regenerator';

const asyncFunc = _asyncToGenerator(function* () {
  yield Promise.resolve('Hello World');
});

Other packages similar to @babel/runtime-corejs3

core-js

core-js is a modular standard library for JavaScript, including polyfills for ECMAScript up to 2021. It's similar to @babel/runtime-corejs3 but does not require Babel to work and can be included directly in any JavaScript project.

regenerator-runtime

regenerator-runtime is a standalone runtime for Regenerator-compiled generator and async functions. It is similar to the regenerator part of @babel/runtime-corejs3 but does not include other polyfills or helpers.

@babel/polyfill

Deprecated in favor of separate core-js and regenerator-runtime packages, @babel/polyfill was a package that included Babel's polyfills for ECMAScript features. It was similar to @babel/runtime-corejs3 but was designed to be included globally rather than modularly.

README

@babel/runtime-corejs3

babel's modular runtime helpers with core-js@3 polyfilling

See our website @babel/runtime-corejs3 for more information.

Install

Using npm:

npm install --save @babel/runtime-corejs3

or using yarn:

yarn add @babel/runtime-corejs3

Changelog

v7.20.7 (2022-12-22)

:eyeglasses: Spec Compliance

• babel-helper-member-expression-to-functions, babel-helper-replace-supers, babel-plugin-proposal-class-properties, babel-plugin-transform-classes
  • #15223 fix: Deleting super property should throw (@SuperSodaSea)
• babel-helpers, babel-plugin-proposal-class-properties, babel-plugin-transform-classes, babel-plugin-transform-object-super
  • #15241 fix: Throw correct error types from sed ant class TDZ helpers (@SuperSodaSea)

:bug: Bug Fix

• babel-parser, babel-plugin-transform-typescript
  • #15209 fix: Support auto accessors with TypeScript annotations (@liuxingbaoyu)
• babel-traverse
  • #15287 Fix .parentPath after rename in SwitchCase (@nicolo-ribaudo)
• babel-plugin-transform-typescript, babel-traverse
  • #15284 fix: Ts import type and func with duplicate name (@liuxingbaoyu)
• babel-plugin-transform-block-scoping
  • #15278 Fix tdz analysis for reassigned captured for bindings (@nicolo-ribaudo)
• babel-plugin-proposal-async-generator-functions, babel-preset-env
  • #15235 fix: Transform for await with shadowed variables (@liuxingbaoyu)
• babel-generator, babel-plugin-proposal-optional-chaining
  • #15258 fix: Correctly generate (a ?? b) as T (@liuxingbaoyu)
• babel-plugin-transform-react-jsx, babel-types
  • #15233 fix: Emit correct sourcemap ranges for JSXText (@liuxingbaoyu)
• babel-core, babel-helpers, babel-plugin-transform-computed-properties, babel-runtime-corejs2, babel-runtime-corejs3, babel-runtime
  • #15232 fix: Computed properties should keep original definition order (@SuperSodaSea)
• babel-helper-member-expression-to-functions, babel-helper-replace-supers, babel-plugin-proposal-class-properties, babel-plugin-transform-classes
  • #15223 fix: Deleting super property should throw (@SuperSodaSea)
• babel-generator
  • #15216 fix: Print newlines for leading Comments of TSEnumMember (@liuxingbaoyu)

:nail_care: Polish

• babel-plugin-transform-block-scoping, babel-traverse
  • #15275 Improve relative execution tracking in fn exprs (@nicolo-ribaudo)

:house: Internal

• babel-helper-define-map, babel-plugin-transform-property-mutators
  • #15274 Inline & simplify @babel/helper-define-map (@nicolo-ribaudo)
• babel-core, babel-plugin-proposal-class-properties, babel-plugin-transform-block-scoping, babel-plugin-transform-classes, babel-plugin-transform-destructuring, babel-plugin-transform-parameters, babel-plugin-transform-regenerator, babel-plugin-transform-runtime, babel-preset-env, babel-traverse
  • #15200 Rewrite transform-block-scoping plugin (@nicolo-ribaudo)

:running_woman: Performance

• babel-helper-compilation-targets
  • #15228 perf: Speed up getTargets (@liuxingbaoyu)