Registry / babel-polyfill-safer

babel-polyfill-safer

library6.6.1jsnpmunverified

A wrapper around babel-polyfill (v6.6.1) that prevents errors when the polyfill is required multiple times. It checks a global flag to avoid re-applying polyfills, solving the 'only one instance of babel-polyfill is allowed' issue. The package is intended for legacy Babel 6 environments, is no longer actively developed, and users should migrate to @babel/polyfill or direct core-js/regenerator-runtime imports.

npm install babel-polyfill-safer

github ↗package ↗

INSTALL

IMPORT

SIG · BABEL-POLYFILL-SAF

babel-polyfill-safer

javascriptv6.6.1

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

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

babel-polyfill-safe

✓ import 'babel-polyfill-safe'

✗ const polyfill = require('babel-polyfill-safe')

Used as a side-effect import, no named exports. Usually placed at entry point.

default

✓ require('babel-polyfill-safe')

✗ const { default } = require('babel-polyfill-safe')

CommonJS require works, but there is no default export.

global._babelPolyfill

✓ if (global._babelPolyfill) { /* skip */ }

✗ defining global._babelPolyfill manually before import

Internal mechanism; not meant for direct use.

Shows how to safely import the polyfill to avoid duplicate instance errors.

// Ensure you have babel-polyfill installed // npm install babel-polyfill babel-polyfill-safe // At the very top of your entry file: import 'babel-polyfill-safe'; // Or with CommonJS: require('babel-polyfill-safe'); // Now you can use modern features without worrying about multiple polyfill instances. // Example: const fn = () => {}; const promise = Promise.resolve();

Debug

Known issues

deprecatedbabel-polyfill-safe is designed for Babel 6; Babel 7+ uses @babel/polyfill which has its own safety mechanisms.

fix

Migrate to @babel/polyfill or directly import core-js/stable and regenerator-runtime/runtime.

affects: <=6.6.1

gotchaThis package only prevents the 'only one instance' error; it does not version-check the polyfill content. If two different versions of babel-polyfill are required, behavior is undefined.

fix

Ensure all dependencies use the same version of babel-polyfill; prefer deduplicating via npm/yarn.

affects: *

gotchaThe package sets global._babelPolyfill = true after first require, which may conflict with other polyfill libraries that check the same global flag.

fix

Avoid mixing multiple polyfill wrappers; stick to one official method.

affects: *

Errors

Common errors & fixes

Error: only one instance of babel-polyfill is allowed

Multiple packages install and import babel-polyfill separately.

fix

Replace all 'babel-polyfill' imports with 'babel-polyfill-safe' in your project and dependencies.

ReferenceError: regeneratorRuntime is not defined

Despite using babel-polyfill-safe, some async/transform require regenerator-runtime which might not be included.

fix

Ensure babel-polyfill (>=6.6.1) is installed; it includes regenerator-runtime.

Cannot find module 'babel-polyfill'

babel-polyfill is a peer dependency but not installed.

fix

Run: npm install babel-polyfill@^6.6.1

Upgrade

Version history

6.6.1latest on npm

Audit

Dependencies

babel-polyfillrequiredcore polyfill that gets wrapped; must be installed as a peer dependency

Agent activity

3 hits · last 30 days

node

Resources

githubhttps://github.com/andrew-w-ross/babel-polyfill-safe ↗

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