Flutter Test

Generate Flutter tests following best practices for BLoC-based state management.

Required Test Dependencies

Ensure the project has these dev_dependencies before generating tests:

dev_dependencies:
  flutter_test:
    sdk: flutter
  bloc_test: ^10.0.0
  mocktail: ^1.0.4

Default mocking stack for this skill remains:

• bloc_test for BLoC/Cubit behavior tests.
• mocktail for repositories/services and interaction verification.

Requirements

General

• Use Flutter test conventions and idioms.
• Always separate:
  • Unit tests (BLoC, Cubit, business logic)
  • Widget tests (UI behavior, rendering, interaction)
• Tests must be deterministic and isolated.
• Always use English for test names and comments.
• Prefer readability and clarity over brevity.

Unit Test Requirements (State Management)

• Use bloc_test for all Bloc or Cubit testing.

• Tests must:

  • Clearly describe initial state, action, and expected states
  • Use blocTest<TBloc, TState>

• Each public event or method must have:

  • At least one success case
  • At least one failure or edge case (if applicable)

• Avoid testing UI-related logic in unit tests.

• Use mocktail for mocking dependencies:

  • Repositories
  • Data sources
  • External services

• Do NOT use real implementations in unit tests.

Widget Test Requirements

• Use flutter_test with WidgetTester.
• Widget tests must:
  • Verify rendered UI states (loading, success, error)
  • Test user interactions (tap, input, scroll)
  • Assert visible behavior, not implementation details
• Inject mocked BLoCs using:
  • BlocProvider.value
  • or MultiBlocProvider
• Avoid golden tests unless explicitly requested.

Assertions & Style

• Prefer:
  • expect for standard assertions
  • verify / verifyNever from mocktail for interaction checks
• Avoid excessive pumpAndSettle; prefer explicit pump durations.
• Use descriptive test names:
  • "emits [Loading, Success] when fetch is successful"

Coverage Guidelines

• Aim for minimum ≥80% coverage at the package or feature level.
• Coverage must include:
  • All major BLoC state transitions
  • At least one widget test per critical UI state
• Do not introduce meaningless assertions just to increase coverage.
• If ≥80% coverage cannot be achieved without testing private details:
  • Explain briefly why
  • Suggest a refactor (e.g. extract logic into BLoC or service)

Output Expectations

• Generate complete and runnable test files.
• Follow Flutter naming conventions:
  • *_bloc_test.dart
  • *_widget_test.dart
• Include all required imports.
• Separate Arrange / Act / Assert clearly.
• Output test code only unless explanation is explicitly requested.

When to Load References

• Detailed technical reference: REFERENCE.md.

Unit Tests (BLoC / Cubit)

• BLoC testing patterns: unit_bloc_testing.md
• Mocking with mocktail: mocktail.md

Widget Tests

• Widget testing fundamentals: widget_testing.md
• Testing BLoC-powered widgets: bloc_widget_testing.md

Additional Guidelines

• Prefer testing behavior over structure.
• Avoid testing Flutter framework internals.
• Do not mock Flutter SDK classes unless unavoidable.
• If a widget is hard to test:
  • Explain why briefly
  • Suggest architectural improvement (e.g. push logic into BLoC).

For auth output contract and concrete auth examples, see REFERENCE.md.