Springboot Verification

# Spring Boot Verification Loop

Run before PRs, after major changes, and pre-deploy.

## When to Activate

- Before opening a pull request for a Spring Boot service
- After major refactoring or dependency upgrades
- Pre-deployment verification for staging or production
- Running full build → lint → test → security scan pipeline
- Validating test coverage meets thresholds

## Phase 1: Build

```bash
mvn -T 4 clean verify -DskipTests
# or
./gradlew clean assemble -x test
```

If build fails, stop and fix.

## Phase 2: Static Analysis

Maven (common plugins):
```bash
mvn -T 4 spotbugs:check pmd:check checkstyle:check
```

Gradle (if configured):
```bash
./gradlew checkstyleMain pmdMain spotbugsMain
```

## Phase 3: Tests + Coverage

```bash
mvn -T 4 test
mvn jacoco:report   # verify 80%+ coverage
# or
./gradlew test jacocoTestReport
```

Report:
- Total tests, passed/failed
- Coverage % (lines/branches)

### Unit Tests

Test service logic in isolation with mocked dependencies:

```java
@ExtendWith(MockitoExtension.class)
class UserServiceTest {

  @Mock private UserRepository userRepository;
  @InjectMocks private UserService userService;

  @Test
  void createUser_validInput_returnsUser() {
    var dto = new CreateUserDto("Alice", "alice@example.com");
    var expected = new User(1L, "Alice", "alice@example.com");
    when(userRepository.save(any(User.class))).thenReturn(expected);

    var result = userService.create(dto);

    assertThat(result.name()).isEqualTo("Alice");
    verify(userRepository).save(any(User.class));
  }

  @Test
  void createUser_duplicateEmail_throwsException() {
    var dto = new CreateUserDto("Alice", "existing@example.com");
    when(userRepository.existsByEmail(dto.email())).thenReturn(true);

    assertThatThrownBy(() -> userService.create(dto))
        .isInstanceOf(DuplicateEmailException.class);
  }
}
```

### Integration Tests with Testcontainers

Test against a real database instead of H2:

```java
@SpringBootTest
@Testcontainers
class UserRepositoryIntegrationTest {

  @Container
  static PostgreSQLContainer<?> postgres = new PostgreSQLContainer<>("postgres:16-alpine")
      .withDatabaseName("testdb");

  @DynamicPropertySource
  static void configureProperties(DynamicPropertyRegistry registry) {
    registry.add("spring.datasource.url", postgres::getJdbcUrl);
    registry.add("spring.datasource.username", postgres::getUsername);
    registry.add("spring.datasource.password", postgres::getPassword);
  }

  @Autowired private UserRepository userRepository;

  @Test
  void findByEmail_existingUser_returnsUser() {
    userRepository.save(new User("Alice", "alice@example.com"));

    var found = userRepository.findByEmail("alice@example.com");

    assertThat(found).isPresent();
    assertThat(found.get().getName()).isEqualTo("Alice");
  }
}
```

### API Tests with MockMvc

Test controller layer with full Spring context:

```java
@WebMvcTest(UserController.class)
class UserControllerTest {

  @Autowired private MockMvc mockMvc;
  @MockBean private UserService userService;

  @Test
  void createUser_validInput_returns201() throws Exception {
    var user = new UserDto(1L, "Alice", "alice@example.com");
    when(userService.create(any())).thenReturn(user);

    mockMvc.perform(post("/api/users")
            .contentType(MediaType.APPLICATION_JSON)
            .content("""
                {"name": "Alice", "email": "alice@example.com"}
                """))
        .andExpect(status().isCreated())
        .andExpect(jsonPath("$.name").value("Alice"));
  }

  @Test
  void createUser_invalidEmail_returns400() throws Exception {
    mockMvc.perform(post("/api/users")
            .contentType(MediaType.APPLICATION_JSON)
            .content("""
                {"name": "Alice", "email": "not-an-em