node-libs-expo

This package provides React Native (Expo) compatible implementations of Node core modules like stream and http. This is a fork of node-libs-react-native which is a fork of node-libs-browser with a few packages swapped to be compatible in React Native.

Installation

yarn add node-libs-expo && expo install expo-crypto expo-random

Usage

This package exports a mapping of absolute paths to each module implementation, keyed by module name. Modules without React Native compatible implementations are null.

These modules can be used with React Native Packager's metro.config.js or Webpack's resolve.alias.

Usage with React Native Packager

Add a metro.config.js file in the root directory of your React Native project and set resolver.extraNodeModules:

// metro.config.js
module.exports = {
  resolver: {
    extraNodeModules: require('node-libs-expo'),
  },
};

For more information, see this post on Node core modules in React Native.

Globals

Node has certain globals that modules may expect, such as Buffer or process. React Native does not provide these globals. The node-libs-expo/globals module in this package will shim the global environment to add these globals. Just require (or import) this module in your app before anything else.

require('node-libs-expo/globals');
// ...
require('./app.js');

Crypto

If you're trying to use crypto.getRandomValues() specifically, then you need to include this snippet before anything else in your app, but AFTER the "globals" import.

import * as Random from 'expo-random';

// implement window.getRandomValues(), for packages that rely on it
if (typeof window === 'object') {
  if (!window.crypto) window.crypto = {}
  if (!window.crypto.getRandomValues) {
    window.crypto.getRandomValues = async function getRandomValues (arr) {
      let orig = arr
      if (arr.byteLength != arr.length) {
        // Get access to the underlying raw bytes
        arr = new Uint8Array(arr.buffer)
      }
      const bytes = await Random.getRandomBytesAsync(arr.length)
      for (var i = 0; i < bytes.length; i++) {
        arr[i] = bytes[i]
      }

      return orig
    }
  }
}

Modules

The following are the module implementations provided by this package. Some modules also have a "mock" implementation provided in the mock directory. These are replacements with minimal functionality.

Module	RN-compatible	Mock
assert	defunctzombie/commonjs-assert	---
buffer	feross/buffer	buffer.js
child_process	---	---
cluster	---	---
console	Raynos/console-browserify	console.js
constants	juliangruber/constants-browserify	---
crypto	expo-crypto	---
dgram	---	---
dns	---	dns.js
domain	bevry/domain-browser	---
events	Gozala/events	---
fs	tradle/react-native-level-fs	---
http	jhiesey/stream-http	---
https	substack/https-browserify	---
module	---	---
net	---	net.js
os	CoderPuppy/os-browserify	---
path	substack/path-browserify	---
process	shtylman/node-process	process.js
punycode	bestiejs/punycode.js	---
querystring	mike-spainhower/querystring	---
readline	---	---
repl	---	---
stream	nodejs/readable-stream	---
string_decoder	rvagg/string_decoder	---
sys	defunctzombie/node-util	---
timers	jryans/timers-browserify	---
tls	---	tls.js
tty	substack/tty-browserify	tty.js
url	defunctzombie/node-url	---
util	defunctzombie/node-util	---
vm	---	vm.js
zlib	devongovett/browserify-zlib	---

Other React Native Modules

These are other React Native packages that implement Node core related modules. They are not included in node-libs-expo, but you may find them useful separately.

dgram

react-native-udp implements Node's dgram API, but is not included here due to its native implementation and need to use react-native link.

net

react-native-tcp implement's Node's net API, but is not included here due to its native implementation and need to use react-native link.

Credit

This is a fork of node-libs-react-native which is a fork of node-libs-browser with minor modifications and packages swapped out for React Native implementations. Thanks to those package authors for doing the hard work.

License

MIT