dart-flutter-patterns

Topics in the source

• Dart/Flutter Patterns
• When to Use
• How It Works
• Examples
• 1. Null Safety Fundamentals
• Prefer Patterns Over Bang Operator
• Avoid late Overuse
• 2. Immutable State

Use this skill when: Starting a new Flutter feature and need idiomatic patterns for state management, navigation, or data access Reviewing or writing Dart code and need guidance on null safety, sealed types, or async composition Setting up a new Flutter project and choosing between BLoC, Riverpod, or Provider Implementing secure HTTP clients, WebView integration, or local storage Writing tests for Flutter widgets, Cubits, or Riverpod providers Wiring up GoRouter with authentication guards This skill provides copy-paste-ready Dart/Flutter code patterns organized by concern: 1. Null safety — avoid !, prefer ?./??/pattern matching 2. Immutable state — sealed classes, freezed, copyWith 3. Async composition — concurrent Future.wait, safe BuildContext after await 4. Widget architecture — extract to classes (not methods), const propagation, scoped rebuilds 5. State management — BLoC/Cubit events, Riverpod notifiers and derived providers 6. Navigation — GoRouter with reactive auth guards via refreshListenable 7. Networking — Dio with interceptors, token refresh with one-time retry guard 8. Error handling — global capture, ErrorWidget.builder, crashlytics wiring 9. Testing — unit (BLoC test

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