Unit Testing

Backend (Java/Spring Boot) → backend/src/test/java/

Frontend (React) → frontend/src/__tests__/

Patrones core

Backend — JUnit 5 + Mockito

// Service Test con @Mock y @InjectMocks
@ExtendWith(MockitoExtension.class)
class FeatureServiceTest {

    @Mock
    private FeatureRepository repository;

    @InjectMocks
    private FeatureService service;

    @Test
    void createFeature_success() {
        // Arrange
        FeatureCreateDTO dto = new FeatureCreateDTO();
        dto.setName("Test Feature");
        
        when(repository.save(any(Feature.class))).thenAnswer(invocation -> {
            Feature f = invocation.getArgument(0);
            f.setUid("uuid-123");
            return f;
        });

        // Act
        FeatureResponseDTO result = service.create(dto, "user-uid");

        // Assert
        assertEquals("uuid-123", result.getUid());
        assertEquals("Test Feature", result.getName());
        verify(repository).save(any(Feature.class));
    }

    @Test
    void getFeature_notFound_throwsException() {
        // Arrange
        when(repository.findByUid("nonexistent")).thenReturn(Optional.empty());

        // Act & Assert
        assertThrows(FeatureNotFoundException.class, 
            () -> service.getByUid("nonexistent"));
    }
}

// Controller Test con MockMvc
@WebMvcTest(FeatureController.class)
class FeatureControllerTest {

    @Autowired
    private MockMvc mockMvc;

    @MockBean
    private FeatureService service;

    @Test
    void createFeature_returns201() throws Exception {
        when(service.create(any(), anyString()))
            .thenReturn(new FeatureResponseDTO("uid-1", "Test", null, LocalDateTime.now()));

        mockMvc.perform(post("/api/v1/features")
                .contentType(MediaType.APPLICATION_JSON)
                .header("X-API-Key", "test-key")
                .content("{\"name\": \"Test\"}"))
            .andExpect(status().isCreated())
            .andExpect(jsonPath("$.uid").value("uid-1"));
    }

    @Test
    void getFeature_notFound_returns404() throws Exception {
        when(service.getByUid("nonexistent"))
            .thenThrow(new FeatureNotFoundException("Not found"));

        mockMvc.perform(get("/api/v1/features/nonexistent")
                .header("X-API-Key", "test-key"))
            .andExpect(status().isNotFound());
    }
}

Frontend — Vitest + Testing Library

// Service mock + renderHook (React)
vi.mock('../../services/featureService');
getFeatures.mockResolvedValue([{ uid: '1', name: 'Test' }]);

const { result } = renderHook(() => useFeature());
await waitFor(() => expect(result.current.data).toHaveLength(1));

Restricciones

• Backend: solo en src/test/java/. No modificar código fuente.
• Frontend: solo en __tests__/. No modificar código fuente.
• Nunca conectar a DB real — usar @DataJpaTest con H2 o mocks con Mockito.
• Cobertura mínima ≥ 80% en lógica de negocio.