JetBrainsのJunieを使ってみた（導入編）

dependencies {
  implementation 'org.springframework.boot:spring-boot-starter'
  compileOnly 'org.projectlombok:lombok'
  developmentOnly 'org.springframework.boot:spring-boot-devtools'
  annotationProcessor 'org.springframework.boot:spring-boot-configuration-processor'
  annotationProcessor 'org.projectlombok:lombok'
  testImplementation 'org.springframework.boot:spring-boot-starter-test'
  testRuntimeOnly 'org.junit.platform:junit-platform-launcher'
}

@Entity
@Table(name = "employees")
@Data
@NoArgsConstructor
@AllArgsConstructor
public class Employee {
  @Id
  @GeneratedValue(strategy = GenerationType.IDENTITY)
  private Long id;

  @NotBlank private String name;

  @Email
  @NotBlank
  @Column(unique = true)
  private String email;

  @NotBlank private String department;

  @PastOrPresent private LocalDate hireDate;
}

public interface EmployeeRepository extends JpaRepository<Employee, Long> {
  Optional<Employee> findByEmail(String email);
}

@RestController
@RequestMapping("/employees")
public class EmployeeController {

  // ---------- ＜中略＞ ---------- //

  @PostMapping
  @ResponseStatus(HttpStatus.CREATED)
  public Employee create(@RequestBody @Valid Employee employee) {
    try {
      employee.setId(null);
      return repository.save(employee);
    } catch (DataIntegrityViolationException e) {
      throw new ResponseStatusException(HttpStatus.CONFLICT, "Email already exists");
    }
  }

  @GetMapping
  public List<Employee> list() {
    return repository.findAll();
  }

  @GetMapping("/{id}")
  public Employee get(@PathVariable Long id) {
    return repository
        .findById(id)
        .orElseThrow(() -> new ResponseStatusException(HttpStatus.NOT_FOUND));
  }

  @PutMapping("/{id}")
  public Employee update(@PathVariable Long id, @RequestBody @Valid Employee updated) {
    Employee existing =
        repository
            .findById(id)
            .orElseThrow(() -> new ResponseStatusException(HttpStatus.NOT_FOUND));
    
    // ---------- ＜中略＞ ---------- //

    try {
      return repository.save(existing);
    } catch (DataIntegrityViolationException e) {
      throw new ResponseStatusException(HttpStatus.CONFLICT, "Email already exists");
    }
  }

  @DeleteMapping("/{id}")
  @ResponseStatus(HttpStatus.NO_CONTENT)
  public void delete(@PathVariable Long id) {
    if (!repository.existsById(id)) {
      throw new ResponseStatusException(HttpStatus.NOT_FOUND);
    }
    repository.deleteById(id);
  }
}

dependencies {
    implementation 'org.springframework.boot:spring-boot-starter-web'
    implementation 'org.springframework.boot:spring-boot-starter-validation'
    implementation 'org.springframework.boot:spring-boot-starter-data-jpa'
    runtimeOnly 'com.h2database:h2'

    // ---------- ＜中略＞ ---------- // 
}

spring:
  application:
    name: mamezou-blog-restapi
  datasource:
    url: jdbc:h2:mem:employees;DB_CLOSE_DELAY=-1;DB_CLOSE_ON_EXIT=FALSE
    driverClassName: org.h2.Driver
    username: sa
    password: ""
  jpa:
    hibernate:
      ddl-auto: update
  h2:
    console:
      enabled: true
      path: /h2-console

@WebMvcTest(EmployeeController.class)
class EmployeeControllerTest {

  @Autowired MockMvc mockMvc;
  @Autowired ObjectMapper objectMapper;

  @MockBean EmployeeRepository repository;

  private Employee sample(Long id) {
    return new Employee(id, "Taro Yamada", "taro@example.com", "IT", LocalDate.of(2020, 1, 1));
  }

  @Test
  @DisplayName("POST /employees - creates employee and returns 201")
  void create_success() throws Exception {
    Employee input = sample(null);
    Employee saved = sample(1L);

    when(repository.save(any(Employee.class))).thenReturn(saved);

    mockMvc
        .perform(
            post("/employees")
                .contentType(MediaType.APPLICATION_JSON)
                .content(objectMapper.writeValueAsString(input)))
        .andExpect(status().isCreated())
        .andExpect(jsonPath("$.id").value(1))
        .andExpect(jsonPath("$.email").value("taro@example.com"));
  }

  // ---------- ＜中略＞ ---------- //

  @Test
  @DisplayName("GET /employees/{id} - returns employee or 404")
  void get_by_id() throws Exception {
    when(repository.findById(1L)).thenReturn(Optional.of(sample(1L)));
    when(repository.findById(99L)).thenReturn(Optional.empty());

    mockMvc
        .perform(get("/employees/1"))
        .andExpect(status().isOk())
        .andExpect(jsonPath("$.id").value(1));
    mockMvc.perform(get("/employees/99")).andExpect(status().isNotFound());
  }

  // ---------- ＜後略＞ ---------- //

}