node-stdlib-browser

Node standard library for browser.

Features:

• Based on node-libs-browser for Webpack
• Maintained with newer versions and modern implementations
• Works with Webpack, Rollup, Vite, esbuild and Browserify, but should also work with other bundlers
• Exports implementation with node: protocol which allows for builtin modules to be referenced by valid absolute URL strings

Check example to see how modules work in browser environment.

Install

npm install node-stdlib-browser --save-dev

Usage

Webpack

As of Webpack 5, aliases and globals provider need to be explicitly configured. If you want to handle node: protocol imports, you need to provide helper plugin.

// webpack.config.js
const stdLibBrowser = require('node-stdlib-browser');
const {
	NodeProtocolUrlPlugin
} = require('node-stdlib-browser/helpers/webpack/plugin');
const webpack = require('webpack');

module.exports = {
	// ...
	resolve: {
		alias: stdLibBrowser
	},
	plugins: [
		new NodeProtocolUrlPlugin(),
		new webpack.ProvidePlugin({
			process: stdLibBrowser.process,
			Buffer: [stdLibBrowser.buffer, 'Buffer']
		})
	]
};

If you’re using ESM config, additional configuration is needed to handle unspecified extensions:

// webpack.config.js
module.exports = {
	// ...
	module: {
		rules: [
			{
				test: /\.m?js$/,
				resolve: {
					fullySpecified: false
				}
			}
		]
	}
};

Rollup

Since many packages expose only CommonJS implementation, you need to apply plugins to handle CommonJS exports. Those packages could have dependencies installed with npm so they need to be properly resolved (taking into account browser-specific implementations).

Some dependencies can have circular dependencies and Rollup will warn you about that. You can ignore these warnings with helper function (reference).

// rollup.config.js
const stdLibBrowser = require('node-stdlib-browser');
const {
	handleCircularDependancyWarning
} = require('node-stdlib-browser/helpers/rollup/plugin');
const { default: resolve } = require('@rollup/plugin-node-resolve');
const commonjs = require('@rollup/plugin-commonjs');
const json = require('@rollup/plugin-json');
const alias = require('@rollup/plugin-alias');
const inject = require('@rollup/plugin-inject');

module.exports = {
	// ...
	plugins: [
		alias({
			entries: stdLibBrowser
		}),
		resolve({
			browser: true
		}),
		commonjs(),
		json(),
		inject({
			process: stdLibBrowser.process,
			Buffer: [stdLibBrowser.buffer, 'Buffer']
		})
	],
	onwarn: (warning, rollupWarn) => {
		handleCircularDependancyWarning(warning, rollupWarn);
	}
};

Vite

Vite config uses combination of Rollup and esbuild plugins. node: protocol imports are currently not supported (issue).

const inject = require('@rollup/plugin-inject');

module.exports = async () => {
	const { default: stdLibBrowser } = await import('node-stdlib-browser');
	return {
		resolve: {
			alias: stdLibBrowser
		},
		optimizeDeps: {
			include: ['buffer', 'process']
		},
		plugins: [
			{
				...inject({
					global: [
						require.resolve(
							'node-stdlib-browser/helpers/esbuild/shim'
						),
						'global'
					],
					process: [
						require.resolve(
							'node-stdlib-browser/helpers/esbuild/shim'
						),
						'process'
					],
					Buffer: [
						require.resolve(
							'node-stdlib-browser/helpers/esbuild/shim'
						),
						'Buffer'
					]
				}),
				enforce: 'post'
			}
		]
	};
};

esbuild

Using esbuild requires you to use helper utilities and plugins.

const path = require('path');
const esbuild = require('esbuild');
const plugin = require('node-stdlib-browser/helpers/esbuild/plugin');
const stdLibBrowser = require('node-stdlib-browser');

(async () => {
	await esbuild.build({
		// ...
		inject: [require.resolve('node-stdlib-browser/helpers/esbuild/shim')],
		define: {
			global: 'global',
			process: 'process',
			Buffer: 'Buffer'
		},
		plugins: [plugin(stdLibBrowser)]
	});
})();

Browserify

Bundling ES modules is currently not supported natively in Browserify, but you can try using esmify or babelify for transforming to CommonJS first.

const fs = require('fs');
const path = require('path');
const browserify = require('browserify');
const aliasify = require('aliasify');
const stdLibBrowser = require('node-stdlib-browser');

const b = browserify(
	[
		/* ... */
	],
	{
		// ...
		transform: [[aliasify, { aliases: stdLibBrowser }]],
		insertGlobalVars: {
			process: () => {
				return `require('${stdLibBrowser.process}')`;
			},
			Buffer: () => {
				return `require('${stdLibBrowser.buffer}').Buffer`;
			}
		}
	}
);

Package contents

| Module | Browser implementation | Mock implementation | Notes | | --------------------- | --------------------------------------------------------------------------------- | -------------------------- | ----------------------------------------------------------------------------------------------------- | | assert | assert | | | buffer | buffer | buffer | buffer@5 for IE 11 support | | child_process | | | | cluster | | | | console | console-browserify | console | | constants | constants-browserify | | | crypto | crypto-browserify | | | dgram | | | | dns | | dns | | domain | domain-browser | | | events | events | | | fs | | | Mocking fs | | http | stream-http | | | https | https-browserify | | | module | | | | net | | net | | os | os-browserify | | | path | path-browserify | | | process | process | process | | punycode | punycode | | punycode@1 for browser support | | querystring | querystring-es3 | | Contains additional exports from newer Node versions | | readline | | | | repl | | | | stream | stream-browserify | | | string_decoder | string_decoder | | | sys | util | | | timers | timers-browserify | | | timers/promises | isomorphic-timers-promises | | | tls | | tls | | tty | tty-browserify | tty | | url | node-url | | Contains additional exports from newer Node versions (URL and URLSearchParams are not polyfilled) | | util | util | | | vm | vm-browserify | | | zlib | browserify-zlib | | | _stream_duplex | readable-stream | | | _stream_passthrough | readable-stream | | | _stream_readable | readable-stream | | | _stream_transform | readable-stream | | | _stream_writable | readable-stream | |

API

packages

Returns: object

Exports absolute paths to each module directory (where package.json is located), keyed by module names. Modules without browser replacements return module with default export null.

Some modules have mocks in the mock directory. These are replacements with minimal functionality.

Tips

Mocking fs

fs package doesn’t return anything since there are many different ways you can implement file system functionality in browser.

Examples of implementations:

• BrowserFS
• fs-web
• browserify-fs
• mock-fs
• memfs

Node support

Minimum supported version should be Node 10.

If you’re using ESM in Node < 12.20, note that subpath patterns are not supported so mocks can’t be handled. In that case, it’s recommended to use CommonJS implementation.

Browser support

Minimum supported version should be Internet Explorer 11, but most modules support even Internet Explorer 9.

Types

You can use default @types/node types.

License

MIT © Ivan Nikolić