Eject mobile app to React Native with Expo modules

[tanx]

Once ExpoKit migrates to universal modules we can use a vanilla React Native project instead for more flexibility:

We will add an option to eject to a plain React Native app with most Expo APIs installed in the project but none of the infrastructure for versioning, multiplexing, or code & asset delivery. You will be in the same position as if you had started your project with react-native init but with a set of high quality and well maintained APIs already installed and configured.

See: https://blog.expo.io/expokit-2019-1e5cb02106f8

[tanx]

@halseth @valentinewallace @Roasbeef @bryanvu since we discussed this a while ago, I'll give a quick refresher on why this effort is necessary...

As outlined in https://blog.expo.io/expokit-2019-1e5cb02106f8 the Expo project is moving away from a monolithic architecture and towards allowing developers to eject to vanilla react-native projects. Developers can then import only the necessary native expo-* module dependencies (see: https://github.com/unimodules/react-native-unimodules and https://github.com/expo/expo/tree/master/packages).

The motivation behind using a vanilla react-native project is that we have more flexibility than a managed expo project i.e. no dependency on any expo.io infrastructure, no potential OTA updates of the JS bundle, and a minimal footprint for native module dependencies. Next to the obvious security, download size, and performance advantages this should give us more flexibility for automated CI builds using fastlane (see: https://carloscuesta.me/blog/shipping-react-native-fastlane-travis/). I've made some progress on this last week and wanted to document it here.

What's already done:

• Generated boilerplate code and xcode/android-studio projects using expo init --template bare-minimum (see: https://github.com/unimodules/react-native-unimodules)
• Imported and wire up only required native modules (expo-barcode-scanner, expo-font, expo-keep-awake, expo-local-authentication, expo-random, expo-secure-store, react-native-svg, react-navigation)
• Imported JS npm dependencies from previous expokit-32 branch
• Wired up app JS code
• Refactor react-native build resolver rn-cli.config.js

Still Todo:

• For some reason webpack can't find/load the custom font * .ttf files under /src/asset/font
• Still need to wire up LndReactModule
• Migrate splash screens and app icons from expokit-32 branch

The effort is ongoing in the branch: dev/bare-react-native