rollup-plugin-node-polyfills

What is rollup-plugin-node-polyfills?

The rollup-plugin-node-polyfills package provides polyfills for Node.js core modules, allowing you to use Node.js-specific modules in a browser environment when bundling with Rollup.

What are rollup-plugin-node-polyfills's main functionalities?

Buffer Polyfill

This feature allows you to use the Buffer module, which is a core module in Node.js, in a browser environment. The code sample demonstrates creating a Buffer from a string and converting it to a hexadecimal string.

import { Buffer } from 'buffer';
const buf = Buffer.from('Hello World', 'utf8');
console.log(buf.toString('hex'));

Stream Polyfill

This feature allows you to use the Stream module in a browser environment. The code sample demonstrates creating a readable stream and pushing data into it.

import { Readable } from 'stream';
const readable = new Readable();
readable.push('Hello World');
readable.push(null);
readable.on('data', (chunk) => {
  console.log(chunk.toString());
});

Crypto Polyfill

This feature allows you to use the Crypto module in a browser environment. The code sample demonstrates creating a SHA-256 hash of a string.

import { createHash } from 'crypto';
const hash = createHash('sha256');
hash.update('Hello World');
console.log(hash.digest('hex'));

Other packages similar to rollup-plugin-node-polyfills

rollup-plugin-polyfill-node

The rollup-plugin-polyfill-node package provides similar functionality by polyfilling Node.js core modules for use in a browser environment. It is an alternative to rollup-plugin-node-polyfills and offers a similar set of polyfills.

browserify

Browserify is a tool that allows you to use Node.js modules in the browser by bundling up all of your dependencies. It includes built-in support for many Node.js core modules, making it a more comprehensive solution compared to rollup-plugin-node-polyfills.

webpack

Webpack is a popular module bundler that can also polyfill Node.js core modules for use in the browser. With the appropriate configuration and plugins, Webpack can provide similar functionality to rollup-plugin-node-polyfills, but it is a more general-purpose tool with a broader range of features.

README

rollup-plugin-node-polyfills

npm install --save-dev rollup-plugin-node-polyfills

Allows the node builtins to be required/imported.

The following modules include ES6 specific version which allow you to do named imports in addition to the default import and should work fine if you only use this plugin.

• process*
• events
• stream*
• util*
• path
• buffer*
• querystring
• url*
• string_decoder*
• punycode
• http*†
• https*†
• os*
• assert*
• constants
• timers*
• console*‡
• vm*§
• zlib*
• tty
• domain
• dns∆
• dgram∆
• child_process∆
• cluster∆
• module∆
• net∆
• readline∆
• repl∆
• tls∆
• fs˚
• crypto˚

† the http and https modules are actually the same and don't differentiate based on protocol

‡ default export only, because it's console, seriously just use the global

§ vm does not have all corner cases and has less of them in a web worker

∆ not shimmed, just returns mock

˚ optional, add option to enable browserified shim

Crypto is not shimmed and and we just provide the commonjs one from browserify and it will likely not work, if you really want it please pass {crypto: true} as an option.

Not all included modules rollup equally, streams (and by extension anything that requires it like http) are a mess of circular references that are pretty much impossible to tree-shake out, similarly url methods are actually a shortcut to a url object so those methods don't tree shake out very well, punycode, path, querystring, events, util, and process tree shake very well especially if you do named imports.

config for using this with something simple like events or querystring

import nodePolyfills from 'rollup-plugin-node-polyfills';
rollup({
  entry: 'main.js',
  plugins: [
    nodePolyfills()
  ]
})

and now if main contains this, it should just work

import EventEmitter from 'events';
import {inherits} from 'util';

// etc

Config for something more complicated like http

import nodePolyfills from 'rollup-plugin-node-polyfills';
rollup({
  entry: 'main.js',
  plugins: [
    nodePolyfills()
  ]
})

License

MIT except ES6 ports of browserify modules which are whatever the original library was.