CLAUDE.md for React Native + Expo

A CLAUDE.md covering the prebuild workflow, platform-fork conventions, and the native-dependency gotchas that break hot reload.

# CLAUDE.md - Trailhead (React Native + Expo)

## Commands
```bash
npx expo start                 # dev; i = iOS simulator, a = Android
pnpm test -- ComposeScreen     # single suite (full run is slow, avoid while iterating)
pnpm lint && pnpm typecheck    # CI gates
npx expo prebuild --clean      # only after native config changes in app.json
```

## Architecture
- Expo Router: file-based screens under `app/`; shared layouts in `_layout.tsx`.
- Server cache is TanStack Query (`hooks/queries/`); client state is Zustand
  (`stores/`). Query data never gets copied into a store.
- Native configuration lives in `app.json` + config plugins; `ios/` and
  `android/` are generated by prebuild.

## Conventions
- Platform differences via `.ios.tsx` / `.android.tsx` file forks.
- Styles co-located with `StyleSheet.create`; theme tokens from `theme/` -
  no hardcoded colors.
- New screens follow `app/(tabs)/profile.tsx` for data loading and error states.

## Workflow
- After changing any dependency with native code: `npx expo prebuild --clean`,
  then a fresh dev build - hot reload will lie to you until then.
- Test on both simulators before marking UI work done; Android text rendering
  differs enough to break layouts.

## Do not
- Do not import Node-only modules; this runs on Hermes.
- Do not hand-edit `ios/` or `android/`; they are regenerated output.
- Do not store tokens in AsyncStorage; use `expo-secure-store`.

These examples are released under CC0. Use them freely, no attribution required. They are provided as is, without warranty of any kind: review and adapt them to your project before use, as you are responsible for the outcome of applying them.