Flutter Testing Standards

Testing Standards

Priority: P1 (HIGH)

Ensuring code reliability through multi-layered testing strategies.

Structure

test/
├── unit/ # Business logic & mapping (Blocs, Repositories, UseCases)
├── widget/ # UI component behavior (Screens, Widgets)
└── integration/ # End-to-end flows

Implementation Guidelines

• Testing Pyramid: Maintain ~70% Unit Tests, ~20% Widget Tests, ~10% Integration Tests.
• Mocks: Use mocktail for type-safe, boilerplate-free mocking.
• Unit Tests: Test logic in isolation. Verify all edge cases (Success, Failure, Exception).
• Widget Tests: Test high-value interactions (Button clicks, Error states, Loading indicators).
• BLoC Tests: Use blocTest to verify state emission sequences.
• Code Coverage: Aim for 80%+ coverage on Domain and Presentation (Logic) layers.

Deep Dive References

• Unit Testing Strategies (Test Data Builders, Mocktail)
• Widget Testing Strategies (Robot Pattern)
• Integration Testing (Shared Robots, Real Device)
• Robot Pattern Implementation

🚫 Anti-Patterns

• Thread Sleep: **No Future.delayed**: Use FakeAsync or expectations for deterministic timing.
• Missing Assertions: **No "Execution Only" Tests**: A test without an expect() call is invalid.
• Over-Mocking: **No Mocking Data Classes**: Use real instances for Entities/Models; mock only I/O.
• Test Pollution: **No Shared State**: Ensure every test is Independent (FIRST).

Related Topics

layer-based-clean-architecture | dependency-injection | cicd