fix: add expo-image-picker plugin with iOS camera permissions

[alex-pythonista]

Summary

• Adds expo-image-picker plugin to app.json with iOS permission strings
• Fixes app crash when accessing camera for receipt scanning
• Adds reusable image picker utilities with camera availability detection

Fixes #7

Problem

The iOS app crashes immediately when attempting to use the camera in the receipt form component. iOS requires apps to declare usage descriptions for privacy-sensitive features via NSCameraUsageDescription and NSPhotoLibraryUsageDescription keys in Info.plist.

Additionally, camera functionality silently fails on iOS Simulator with no user feedback.

Solution

1. Added the expo-image-picker plugin configuration to app.json with appropriate permission messages:

[
  "expo-image-picker",
  {
    "photosPermission": "Allow $(PRODUCT_NAME) to access your photos to upload receipt images for transaction extraction.",
    "cameraPermission": "Allow $(PRODUCT_NAME) to access your camera to take photos of receipts for transaction extraction."
  }
]

2. Created reusable utils/imagePicker.ts with:

   • launchCamera() - Camera capture with availability check and permissions
   • launchImageLibrary() - Gallery picker with permissions
   • checkCameraAvailability() - Standalone availability check
   • User-friendly alert when camera is unavailable (e.g., iOS Simulator)

3. Refactored receipt-form.tsx to use the new utilities

Test plan

• Run npx expo prebuild --clean to regenerate native projects
• Run npx expo run:ios to build and launch on iOS
• Navigate to receipt form and tap camera button
• Verify iOS shows permission dialog with configured message
• Verify camera launches successfully after granting permission (physical device)
• Verify helpful alert appears on iOS Simulator when tapping camera
• Verify photo library picker works correctly

🤖 Generated with Claude Code

[alex-pythonista]

Code Review: PR #9

Overview

This PR adds the expo-image-picker plugin configuration to app.json to fix the iOS camera crash caused by missing NSCameraUsageDescription in Info.plist.

Analysis

✅ Correctness

• The fix correctly addresses the root cause (missing iOS permission declarations)
• Plugin configuration follows Expo's official documentation
• Both cameraPermission and photosPermission are included, covering both camera and photo library access used in components/receipt-form.tsx

✅ Code Quality

• Minimal, focused change (+8/-1 lines)
• Proper JSON formatting maintained
• Permission strings are user-friendly and explain the specific use case (receipt scanning)

✅ Conventions

• Uses $(PRODUCT_NAME) Xcode variable as per Apple/Expo best practices
• Plugin placement at the end of the plugins array is appropriate

✅ Security

• Permission strings follow Apple's privacy guidelines by explaining why access is needed
• No over-permissioning (microphonePermission not included since it's not needed)

Suggestions

None - this is a clean, correct fix.

Verdict

LGTM ✅

The change is minimal, correct, and follows best practices. After merging, remember to run:

npx expo prebuild --clean
npx expo run:ios

---

🤖 Reviewed by Claude Code

[alex-pythonista]

Permission preview

Camera Not Available