Loading @polkadot packages in react native app with expo

Question

I am currently working on a react application to complement a web application, and have been tasked with implementing an self-sovereign identity solution using the Kilt.io protocol. This worked fine for the web app, however I am running some issues when it comes to the react native app. I initially wanted to use Expo, however the @kiltprotocol/sdk-js package depends on @polkadot packages to function, which in turn depends on the NodeJS crypto package. However, as it is a NodeJS package, the module cannot be found when trying to run my expo app. It seems like it is possible to load the crypto module using the rn-nodeify package when not using expo (although I have not actually tested this myself for this use case yet), however I was wondering if anyone knows of a solution that would work for an expo project.

Answer 1

Try

1. expo install expo-crypto
2. then create a "metro.config.js"
3. put in

module.exports = {
    resolver: {
        extraNodeModules: {
            crypto: require.resolve('expo-crypto'),
        }
    }
};