babel-runtime

What is babel-runtime?

The babel-runtime npm package is a part of Babel, a JavaScript compiler that allows developers to use next-generation JavaScript, today. It provides runtime support for features that are not supported in older browsers or environments. This includes things like new syntax features and built-in functions. The babel-runtime package helps in avoiding polluting the global scope and reduces the code size by deduplicating helper functions that Babel uses to transpile the code.

What are babel-runtime's main functionalities?

Polyfill for ECMAScript features

This code sample demonstrates how babel-runtime can be used to polyfill newer ECMAScript features such as Promises for environments that do not support them natively.

import 'babel-runtime/core-js/promise';

const p = new Promise((resolve, reject) => {
  setTimeout(resolve, 1000, 'foo');
});

Transforming syntax

This code sample shows how babel-runtime provides helper functions to transform syntax like classes into a format that can be understood by environments that do not support such syntax natively.

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

class Example {
  constructor() {
    _classCallCheck(this, Example);
  }
}

Regenerator for generators and async functions

This code sample illustrates the use of babel-runtime to enable the use of async functions and generators in environments that do not have native support for these features.

import 'babel-runtime/regenerator';

async function asyncCall() {
  console.log('calling');
  const result = await resolveAfter2Seconds();
  console.log(result);
}

Other packages similar to babel-runtime

core-js

Core-js is a modular standard library for JavaScript, which includes polyfills for ECMAScript features. It is similar to babel-runtime in that it provides polyfills, but it is more comprehensive and can be used without Babel.

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 but does not include other babel helpers or polyfills.

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 when compiling to JavaScript, similar to how babel-runtime supports Babel.

README

babel-runtime