Unit Testing

Coverage Target

Layer	Min. Coverage
Use Cases	90%
ViewModels / Cubits	80%
Repositories	80%
Utilities / Extensions	70%
UI Components	50% (widget test)

Framework per Platform

Platform	Framework	Mocking
Android	JUnit 5	MockK / Mockito-Kotlin
iOS	XCTest / Swift Testing	Protocol-based mocking
Flutter	flutter_test	Mockito / Mocktail
React Native	Jest	Jest mocks

What to Test

• ✅ Use cases (input → output)
• ✅ ViewModel state transitions
• ✅ Repository data mapping
• ✅ Utility functions
• ✅ Error handling paths
• ❌ Framework internals
• ❌ Simple getters/setters

Example

Kotlin

class GetUserUseCaseTest {
    private val repository = mockk<UserRepository>()
    private val useCase = GetUserUseCase(repository)

    @Test
    fun `should return user when repository succeeds`() = runTest {
        val expected = User(id = "1", name = "John")
        coEvery { repository.getUser("1") } returns Result.success(expected)

        val result = useCase("1")

        assertTrue(result.isSuccess)
        assertEquals(expected, result.getOrNull())
    }

    @Test
    fun `should return failure when repository fails`() = runTest {
        coEvery { repository.getUser("1") } returns Result.failure(Exception("Not found"))

        val result = useCase("1")

        assertTrue(result.isFailure)
    }
}

Dart

void main() {
  late MockUserRepository mockRepository;
  late GetUserUseCase useCase;

  setUp(() {
    mockRepository = MockUserRepository();
    useCase = GetUserUseCase(mockRepository);
  });

  test('should return user when repository succeeds', () async {
    final expected = User(id: '1', name: 'John');
    when(() => mockRepository.getUser('1'))
        .thenAnswer((_) async => expected);

    final result = await useCase('1');

    expect(result, equals(expected));
    verify(() => mockRepository.getUser('1')).called(1);
  });
}

Naming Convention

Test name harus mendeskripsikan behavior, bukan implementasi:

• ✅ should return user when repository succeeds
• ❌ testGetUser