The project is run by execuing yarn start to start Metro and then (for connected android or emulator) executing yarn android in the separate console.
More about running on iOS simulator: https://reactnative.dev/docs/running-on-simulator-ios
The Android build is done with either yarn build-android or yarn build-android-windows (in Windows). The apk files will be in app/build/outputs/apk/release.
The iOS version is built with CocoaPods, the podfile is in ios/Podfile.
The project uses modern react stack: Typescript, React, Redux, Redux-Observable for epics, jest for unit tests.
Directory-by-directory overview:
Tests are written in Typescript (and typed), run using jest, redux-mock-store, react-test-renderer (for components).
Actions are simple objects, we do not use redux-thunk in favor of epics. This will simplify the actions and move all action-to-action mapping to epics.
The components. Components are written using hooks, some of them just pure functions.
Epics live here.
The app logic is stored here: which actions cause which actions and under which conditions.
Here actions are bound to library (API) calls. This is the only place in the app where actions and library calls are found together. This separation makes it a bit easier to search for and new APIs.
Functions to call different APIs live here, along with all necessary helpers (parsing answers, probably authentication etc). The library definitions are simple async functions, all binding to actions is done in epics/libraryBindings.
Pretty standard redux reducers.
The components for aplication screens (that would've been pages in frontend app).
Helper functions for getting data from the store.
General styles for applications that are not theme-specific. Theme-specific styles (light/dark) live in themes.
Test issues/organizations/repos used in unit tests. Should eventually be moved inside the __tests__.
Common helpers for the whole project.
Typescript types for application entities and API responses (should be separated if more APIs are added).