如何在單元測試中模擬 JPA 存儲庫的保存方法

Question

例如，我在 UserService 中有這個方法：

  @Override
  @Transactional
  public UserDto create(UserDto userDto) {

    User dbUser = userRepository.findOne(userDto.getId());

    if (dbUser != null) {
      throw new AuthException(AuthException.ErrorCode.DUPLICATE_USER_EXCEPTION);
    }

    User oneByLogin = userRepository.findOneByLogin(userDto.getLogin());
    if (oneByLogin != null) {
      throw new AuthExceptionAuthException.ErrorCode.DUPLICATE_LOGIN_EXCEPTION);
    }

    User newUser = new User();
    newUser.setGuid(UUID.randomUUID().toString());
    newUser.setInsertDate(new Date());
    newUser.setFirstName(userDto.getFirstName());
    newUser.setLastName(userDto.getLastName());
    newUser.setLogin(userDto.getLogin());
    newUser.setPassword(userDto.getPassword());
    newUser.setAuthToken(TokenGenerator.nextToken());
    newUser.setAuthTokenCreatedDate(new Date());

    User savedUser = userRepository.save(newUser);

    userDto.setAuthToken(savedUser.getAuthToken());
    log.info("User {0} created", savedUser.getLogin());
    return userDto;
  }

如何為此方法創建單元測試？ 我接下來嘗試：

  @Test
  public void createUser() {

    UserDto userDtoRequest = new UserDto();
    userDtoRequest.setLogin("Alex");
    userDtoRequest.setPassword("123");

    UserDto found = userService.create(userDtoRequest);
    assertThat(found.getAuthToken()).isNotEmpty();
}

我有下一個邏輯：

1. 測試開始
2. User dbUser = userRepository.findOne(userDto.getId()); 數據庫用戶 = NULL
3. if (dbUser != null ) 和if (oneByLogin != null)跳過
4. 創建新用戶並設置數據
5. User savedUser = userRepository.save(newUser); 已保存用戶 = NULL

在這一步中，我遇到了一個問題，因為我無法模擬userRepository.save(newUser) 。

newUser create inside the method. and test fail.

SavedUser.getAuthToken() - savedUser == NULL

我可以重寫：

    userRepository.save(newUser);
    userDto.setAuthToken(newUser.getAuthToken());
    log.info("User {0} created", newUser.getLogin());
    return userDto;

但是如果我想使用返回的對象savedUser呢？

Answer 1

你需要這樣做。

when(userRepository.save(Mockito.any(User.class)))
                .thenAnswer(i -> i.getArguments()[0]);

現在您可以獲得作為參數傳遞的用戶。

Answer 2

您可以執行以下操作：

@RunWith(MockitoJUnitRunner.class)
public class SimpleTest {

  @Mock
  private UserRepository mockedUserRepository;

  // .. your test setup

  @Test
  public void testYourMethod() {

     User userToReturnFromRepository = new User();
     userToReturnFromRepository.setAuthToken(YOUR_TOKEN);
     when(mockedUserRepository.save(any(User.class)).thenReturn(userToReturnFromRepository);

     UserDto found = userService.create(userDtoRequest);

     // ... your asserts

  }

}

使用這種方法，您只需要確保您的mockedUserRepository被注入到您的測試類中（例如在構造函數中）。

Answer 3

您需要編寫多個測試用例來測試不同的場景。

場景一：當findOne返回一個非空對象時：

@Test(expected=AuthException.class)
public void testCreateUserWhenAvailable()    {
     //Create one sample userDto object with test data
     when(mockedUserRepository.findOne(userDto.getId())).thenReturn(new User());
     userService.create(userDto);
}

場景二：當findOneByLogin返回一個空對象時：

@Test(expected=AuthException.class)
public void testCreateUserWhenLoginAvailable()    {
     //Create one sample userDto object with test data
     when(mockedUserRepository.findOne(userDto.getId())).thenReturn(null);
     when(mockedUserRepository.findOneByLogin(userDto.getId())).thenReturn(new User());

     userService.create(userDto);
}

場景2：保存完成后：

@測試

public void testCreateUserWhenSaved()    {
     //Create one sample userDto object with test data
     when(mockedUserRepository.findOne(userDto.getId())).thenReturn(null);
     when(mockedUserRepository.findOneByLogin(userDto.getId())).thenReturn(null);

     //Create sample User object and set all the properties
     User newUser=new User();
     when(mockedUserRepository.save(Mockito.any(User.class)).thenReturn(newUser);
     User returnedUser=userService.create(userDto);
     //You have two ways to test, you can either verify that save method was invoked by 
     //verify method
     verify(mockedUserRepository, times(1)).save(Mockito.any(User.class);
     //or by assertion statements, match the authToken in the returned object to be equal 
     //to the one set by you in the mocked object
     Assert.assertEquals(returnedUser.getAuthToken(),newUser.getAuthToken());
}

Answer 4

關於如何使用@GeneratedValue為字段生成隨機 ID 來創建 JPA 存儲庫save方法只需兩美分。

/**
 * Mocks {@link JpaRepository#save(Object)} method to return the
 * saved entity as it was passed as parameter and add generated ID to it.
 * If ID could not be generated, it will be ignored.
 * If parameter already has and ID, it will be overridden.
 */
private <T, V> void mockSave(JpaRepository<T, V> repository) {
    when(repository.save(any())).thenAnswer(i -> {
        Object argument = i.getArgument(0);
        Arrays.stream(argument.getClass().getDeclaredFields())
                .filter(f -> f.getAnnotation(GeneratedValue.class) != null)
                .forEach(f -> enrichGeneratedValueField(argument, f));
        return argument;
    });
}

因此，在這里您將所需的存儲庫作為參數傳遞，並且這些方法為所有用@GeneratedValue注釋注釋的字段調用enrichGeneratedValueField值字段。 下面是這個方法的實現：

private void enrichGeneratedValueField(Object argument, Field field) {
    try {
        if (field.getType().isAssignableFrom(Integer.class)) {
            FieldUtils.writeField(field, argument, Math.abs(random.nextInt()), true);
        } else {
            FieldUtils.writeField(field, argument, mock(field.getType()), true);
        }
    } catch (Exception ignored) {
    }
}

在這個例子中，我只使用了Integer類型的 ID，但可以隨意添加您想要的 ID 類型。