Running js-libp2p under React Native

There is some setup that needs to be done to modernise the react-native runtime.

1. Shimming globals

Some standard JS APIs aren't available in React Native, these need to be polyfilled, hopefully not forever.

See ./globals.js for the changes you need to make.

2. Enable modern JS features

• libp2p uses ES2022 private properties in some places, so enable transpiling them for use with React Native. At the time of writing loose mode is also required.

$ npm i -D @babel/plugin-transform-private-methods

// babel.config.js
module.exports = {
  //... other config
  plugins: [
    ['@babel/plugin-transform-private-methods', { loose: true }]
  ]
}

3. Add support for missing Node.js APIs

Some dependencies use Node.js APIs so these need to be added to the module resolver.

See ./babel-config.js for the changes you need to make.

Running

Prerequisites

Make sure you have completed the React Native - Environment Setup instructions till "Creating a new application" step, before proceeding.

Run in the simulator

Start Expo:

$ npm i
$ npm start

Follow the instructions - press i to start iOS or a for Android.

Run on a device

See the expo docs

$ npx expo run:android --device

For iOS you will need to provision a device certificate as normal.

$ npx expo run:ios --device

Notes

• @libp2p/webrtc can only run on a device since it needs native code

Debugging

Put this at the top of your app file:

import debug from 'weald'

debug.enable('libp2p:*')