Node Polyfill Plugin#

By using the Node Polyfill plugin, Node core libs polyfills are automatically injected into the browser-side, allowing you to use these modules on the browser side with confidence.

Quick Start#

Install Plugin#

You can install the plugin using the following command:

npm add @rsbuild/plugin-node-polyfill -D

Register Plugin#

You can register the plugin in the rsbuild.config.ts file:

import { pluginNodePolyfill } from '@rsbuild/plugin-node-polyfill';

export default {
  plugins: [pluginNodePolyfill()],
};

Node Polyfills#

Globals#

• Buffer
• process

When you use the above global variables in your code, the corresponding polyfill will be automatically injected.

For instance, the following code would inject the Buffer polyfill:

const bufferData = Buffer.from('abc');

You can disable this behavior through the globals option of the plugin:

pluginNodePolyfill({
  globals: {
    Buffer: false,
    process: false,
  },
});

Modules#

• assert
• buffer
• console
• constants
• crypto
• domain
• events
• http
• https
• os
• path
• punycode
• process
• querystring
• stream
• _stream_duplex
• _stream_passthrough
• _stream_readable
• _stream_transform
• _stream_writable
• string_decoder
• sys
• timers
• tty
• url
• util
• vm
• zlib

When the above module is referenced in code via import / require syntax, the corresponding polyfill will be injected.

import { Buffer } from 'buffer';

const bufferData = Buffer.from('abc');

Fallbacks#

• child_process
• cluster
• dgram
• dns
• fs
• module
• net
• readline
• repl
• tls

Currently there is no polyfill for the above modules on the browser side, so when you import the above modules, it will automatically fallback to an empty object.

import fs from 'fs';

console.log(fs); // -> {}

Options#

globals#

Used to specify whether to inject polyfills for global variables.

• Type:

type Globals = {
  process?: boolean;
  Buffer?: boolean;
};

• Default:

const defaultGlobals = {
  Buffer: true,
  process: true,
};

protocolImports#

Whether to polyfill Node.js builtin modules starting with node:.

• Type: boolean
• Default: true

For example, if you disable protocolImports, modules such as node:path, node:http, etc. will not be polyfilled.

pluginNodePolyfill({
  protocolImports: false,
});