Code Review (Flutter/Dart)

Use this skill when asked to review code or before finalizing significant changes. Focus on the following areas to ensure high quality, stability, and maintainability.

1. Architecture & State Management (BLoC)

• Event/State Immutability: Ensure all Bloc Events and States are immutable (@immutable or using Freezed).
• Logic Separation: UI widgets should only dispatch events and listen to states. Business logic must reside in Blocs or Repositories.
• Bloc Usage:
  • Use BlocBuilder for rebuilding UI part.
  • Use BlocListener for side effects (navigation, toasts, dialogs).
  • Avoid overly complex logic inside build() methods.
• HydratedBloc: Verify that state persistence logic (fromJson/toJson) handles nulls and data migration gracefully.

2. Resource Management & Performance

• Disposal: Check that all Controllers (VideoPlayer, Chewie, TextEditing, Animation), Timers, and Streams are properly disposed in dispose().
• Media Players: Ensure video_player and just_audio instances are stopped/paused before disposal to prevent background audio leaks.
• Build Method: Avoid expensive computations or object instantiations inside build(). Use late final or initState where appropriate.
• const Constructors: Use const for widgets and values wherever possible to optimize rebuilds.

3. Error Handling & Stability

• Network Requests: All Dio requests must be wrapped in try/catch blocks handling DioException.
• FFmpeg: Check for FFmpeg session return codes. Handle cases where merging or conversion fails.
• Permissions: Verify that permission requests (manageExternalStorage, photos, etc.) check the Android SDK version correctly (SDK 30+ vs older).
• Null Safety: strictly avoid force unwrapping (!) unless absolutely certain. Use ?. and ?? defaults.

4. User Interface & UX

• Material 3: Ensure components follow Material 3 design guidelines (use ColorScheme, proper typography).
• Responsiveness: UI should handle different screen sizes and orientations gracefully.
• Dark Mode: Verify correct color usage for both Light and Dark themes (use Theme.of(context).colorScheme).
• Localization: All user-facing text must use easy_localization keys (e.g., "key".tr()). No hardcoded strings.

5. Specific Project patterns

• Background Service: Ensure tasks intended for background execution properly communicate with FlutterForegroundTask.
• Navigation: Use GoRouter for all navigation. Avoid Navigator.push unless working with dialogs/overlays that require it.

6. Security

• Input Validation: Validate all user inputs (especially YouTube URLs).
• File System: Be careful with file path manipulations. Use path_provider and validate paths before writing.