Best Practices

Dart Best Practices

Null Safety

• Always enable null safety (dart migrate).
• Avoid usage of dynamic and Object declaration, always use var or explicit typing.
• Follow the order of const >> final >> var with no nullability specifier >> final late >> var?.
• Avoid non const top-level variables.
• Favor immutable data classes (with freezed or equatable).

Typing

• Avoid dynamic where possible; use explicit types (List<int> instead of List).

Concurrency

• Prefer async/await over .then() for readability.
• Use Future.error for explicit errors instead of throwing strings.
• Leverage FutureOr<T> for flexible async/sync returns.
• Offload CPU-intensive tasks to isolates (e.g., image processing).
• Use compute() for simple parallelism or Isolate.spawn for complex cases.

Collections

• Use collection if/for/spreads for concise code.
• Prefer .map(), .where(), and .fold() over manual loops where appropriate.

Error Handling

• Catch specific exceptions (on SomeException), not just all catch (e).
• Use rethrow when needed to preserve stack traces.

Flutter Best Practices

State Management

• Prefer Provider, Riverpod, Bloc, or GetX over setState
• Avoid global state unless necessary (e.g., use scoped providers).
• Follow BLoC/Cubit or MVVM patterns.
• Keep UI (Widgets) and business logic (Models/Controllers) separate. 2Reactive Programming:
• Use StreamBuilder/FutureBuilder for async UI updates.
• Avoid nested reactive widgets (e.g., minimize StreamBuilder layers). 3State Persistence:
• Use hydrated_bloc or shared_preferences for local state persistence.
• Avoid prop drilling with Provider or Riverpod.
• Use freezed for immutable models and unions.
• Serialize JSON with json_serializable.
• Use MethodChannel for native integrations (Kotlin/Swift).
• Organize layers into data, domain, and presentation.

Widget Optimizations

• Mark widgets as const when possible to prevent unnecessary rebuilds.
• Use const constructors for children in lists/grids.
• Avoid Opacity for animations; prefer AnimatedOpacity or Transform.
• Use ListView.builder (or CustomScrollView) for infinite/large lists (lazy loading).
• Extract expensive computations from build() methods.
• Use Keys (e.g., ValueKey, UniqueKey) when modifying collections of stateful widgets.
• Use precacheImage for images loaded on-demand.

UI/UX Considerations

• Use LayoutBuilder, MediaQuery, or SafeArea.
• Test on multiple screen sizes (e.g., using DevicePreview).
• Add semantic labels (Semantics widget), use ExcludeSemantics where needed.
• Support dynamic text sizing (TextScaler).
• Use intl package with ARB files or flutter_localizations.
• Define a consistent ThemeData in MaterialApp.
• Use ThemeExtensions for custom theming (Flutter 3+).
• Use named routes with go_router for deep linking and simplified navigation.

Performance

• Test performance in profile mode (flutter run --profile).
• Use DevTools to check for jank, memory leaks, and CPU usage.
• Dispose controllers (ScrollController, TextEditingController) and subscriptions.
• Use const widgets to reduce garbage collection.
• Minimize ClipPath, Opacity, and ShaderMask usages in animations.
• Prefer CustomPaint for complex UIs over deep widget trees.
• Compress images (use .webp format).
• Cache images with cached_network_image.

Testing

• Unit Test with mockito or mocktail for mocking.
• Use WidgetTester to verify UI behavior (e.g., pumpAndSettle).
• Run end-to-end tests with integration_test.
• Use golden_toolkit for pixel-perfect UI comparisons.
• Generate reports with flutter test --coverage + lcov.

Deployment & Maintenance

• Use flutter analyze and dart fix.
• Configure analysis_options.yaml with strict lints (flutter_lints package).
• Pin versions in pubspec.yaml (^ for SemVer-compatible updates).
• Audit dependencies with dart pub outdated.
• Use doc comments (///) and generate docs via dart doc.
• Keep README.md updated with project setup and architecture.
• Use sentry_flutter for error tracking.

Platform specific

• ndk version mismatch
  • Set ndkVersion in build.gradle.kts to the specific ndk version installed