Registry / devops / babel-plugin-polyfill-regenerator

babel-plugin-polyfill-regenerator

library0.6.8jsnpmunverified

A Babel plugin that automatically imports regenerator-runtime when generator/async functions are used. Part of the babel-polyfills monorepo, this is the recommended replacement for @babel/plugin-transform-regenerator's built-in helper. Current version 0.6.8, released as part of the @babel/preset-env polyfill strategy. Unlike older approaches, it avoids bundling regenerator-runtime if not needed (tree-shaking friendly) and integrates with the broader babel polyfill ecosystem (corejs, entry/usage transforms). Requires @babel/core >=7.4 or ^8.0.0-0. Deprecated in favor of @babel/plugin-transform-runtime for library authors, but still maintained for use with @babel/preset-env usage-based polyfilling.

devops

npm install babel-plugin-polyfill-regenerator

github ↗package ↗

INSTALL

IMPORT

SIG · BABEL-PLUGIN-POLYF

babel-plugin-polyfill-regenerator

devopsjavascriptv0.6.8

Install

—

Import

—

Disk

—

Pass rate

0/ 6

Env Coverage0 / 6

glibc

18–22

musl

18–22

Install & Compatibility

Where this runs

tested against v? · npm install

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

node 18–226 runs

build_error

glibc

node 18–226 runs

build_error

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

default

✓ module.exports = require('babel-plugin-polyfill-regenerator')

✗ import regenerator from 'babel-plugin-polyfill-regenerator'

This is a Babel plugin; it's imported as a CommonJS module using require(). ESM imports may fail or require .default.

default

✓ plugins: [require('babel-plugin-polyfill-regenerator')]

✗ plugins: [['babel-plugin-polyfill-regenerator', { method: 'usage-global' }]]

The plugin does not accept options; options are passed via the parent preset-env. Passing options incorrectly may cause silent failure.

Configures Babel with preset-env and the regenerator polyfill plugin to automatically inject regenerator-runtime for async/generator functions.

// babel.config.js module.exports = { presets: [ ['@babel/preset-env', { targets: '> 0.25%, not dead', useBuiltIns: 'usage', corejs: 3 }] ], plugins: [ require('babel-plugin-polyfill-regenerator') ] }; // Source (async.js) async function foo() { await bar(); } // Transpiled output (with regenerator import) import "regenerator-runtime/runtime"; // or require(...) function asyncGeneratorStep() { /* ... */ } function _asyncToGenerator(fn) { /* ... */ } var foo = function () { var _ref = _asyncToGenerator( /*#__PURE__*/ regeneratorRuntime.mark(function _callee() { return regeneratorRuntime.wrap(function _callee$(_context) { while (1) { switch (_context.prev = _context.next) { case 0: _context.next = 2; return bar(); case 2: case 'end': return _context.stop(); } } }, _callee); })); return function foo() { return _ref.apply(this, arguments); }; }();

Debug

Known issues

deprecatedThis plugin is deprecated in favor of using @babel/plugin-transform-runtime for libraries or relying on preset-env's built-in polyfill handling. New projects should use @babel/preset-env with corejs and let it handle regenerator automatically.

fix

Remove explicit babel-plugin-polyfill-regenerator and configure @babel/preset-env with useBuiltIns: 'usage' and corejs: 3.

affects: >=0.6.0

breakingIn v0.6.0, the plugin changed its internal logic to align with the broader babel-polyfills refactor. Projects that relied on specific import paths or module injection behavior may break.

fix

Ensure you are using the latest version (0.6.8) and that your Babel configuration does not have conflicting polyfill plugins.

affects: >=0.6.0 <0.6.8

gotchaIf you use this plugin without @babel/preset-env set to useBuiltIns: 'usage', the plugin will not inject any imports because it only triggers when preset-env's polyfill detection marks code as needing regenerator. Standalone use without preset-env will do nothing.

fix

Configure @babel/preset-env with appropriate useBuiltIns setting, or switch to @babel/plugin-transform-runtime for standalone needs.

affects: >=0.0.0

gotchaThe plugin only injects imports for regenerator-runtime, not for other polyfills. To polyfill other features (e.g., promises, array methods), you must also include core-js via @babel/plugin-polyfill-corejs3 or similar.

fix

Add babel-plugin-polyfill-corejs3 or use @babel/preset-env with corejs setting.

affects: >=0.0.0

Errors

Common errors & fixes

SyntaxError: Unexpected token 'import' > 1 | import "regenerator-runtime/runtime";

The plugin injects ESM import statements but the target environment does not support native ESM. This can happen if Babel is configured to output CommonJS but the plugin still outputs import.

fix

Ensure Babel is configured to output CommonJS (e.g., with @babel/preset-env's modules: 'commonjs' or @babel/plugin-transform-modules-commonjs).

Error: [BABEL] ...: Cannot find module 'babel-plugin-polyfill-regenerator'

The package is not installed or is missing from node_modules.

fix

Run npm install babel-plugin-polyfill-regenerator --save-dev

ReferenceError: regeneratorRuntime is not defined

regenerator-runtime is not included at runtime. The plugin assumes regenerator-runtime is a global or imported; if you are using modules, it should work, but if the import is stripped or not loaded, it fails.

fix

Make sure regenerator-runtime is included in your bundle. If using preset-env with useBuiltIns: 'usage', it should inject the import automatically. If not, add import 'regenerator-runtime/runtime' at the entry point.

Upgrade

Version history

0.6.8latest on npm

Audit

Dependencies

@babel/coreoptionalpeer dependency - plugin requires Babel core to transform code

regenerator-runtimerequiredpolyfill that the plugin injects imports for

Agent activity

4 hits · last 30 days

node

Resources

githubhttps://github.com/babel/babel-polyfills ↗

packagehttps://www.npmjs.com/package/babel-plugin-polyfill-regenerator ↗