如何使用 Mockito 为 page.map(mapper::toDto) 模拟

Question

我正在junit为我的方法编写一个测试用例service，它有一个外部调用jpa repository，我想这样做mock。

此方法findall(Pageable pageable)返回page由映射器映射的实体Mapstruct's。但是，NPE当我assert返回时，我得到了一个。可能有一些我遗漏的东西，我不确定如何mock调用这个方法。

我试过像这样编写测试用例测试用例：

public class myTestclass {

@Test

public void testFindAllUser() {

User user1 = new User();

user1.setId(Long.valueOf(1));

User user2 = new User();

user2.setId(Long.valueOf(2));

List<User> userList = new ArrayList<>();

userList.add(user1);

userList.add(asset2);

Pageable pageable = PageRequest.of(0, 5);

Page<User> userPage = new PageImpl<>(userList, pageable, userList.size());

Page<UserDto> userDtoPage = null;

Mockito.when(userRepositoryMock.findAll(pageable)).thenReturn(userPage);

Mockito.when(userPage.map(userMapperMock::toDto)).thenReturn(userDtoPage);// expecting to mock this object in

// some other way.

assertThat(userService.findAll(pageable)).isEqualTo(userDtoPage); // throws NPE

}

}

我正在为其编写测试用例的方法：

public Page<UserDto> findAll(Pageable pageable) 

{

return userRepository.findAll(pageable).map(userMapper::toDto);

}

这是我的映射器类：

@Mapper(componentModel = "spring", uses = { FarmerMapper.class })

public interface UserMapper extends EntityMapper<UserDto, User> {

UserDto toDto(User user);

User toEntity(UserDto userDto);

}

mapper模拟该方法toDto以使其返回页面的正确方法是什么userDto？

Answer 1

由于.map使用UserMapper's toDto方法来转换页面的每个元素，我模拟了多个元素userMapper来解决这个问题。因此，我创建了 2 个页面，一个User用于UserDto. 所以我的测试用例被修改为@Testpublic void testFindAllUser() {User user1 = new User();user1.setId(DEFAULT_ID);User user2 = new User();user2.setId(2L);List<User> userList = new ArrayList<>();userList.add(user1);userList.add(user2);Pageable pageable = PageRequest.of(0, 5);Page<User> userPage = new PageImpl<>(userList, pageable, userList.size());UserDto userDto1 = new UserDto();userDto1.setId(Long.valueOf(1));UserDto userDto2 = new UserDto();userDto2.setId(Long.valueOf(2));List<UserDto> userDtoList = new ArrayList<>();userDtoList.add(userDto1);userDtoList.add(userDto2);Page<UserDto> userDtoPage = new PageImpl<>(userDtoList, pageable, userDtoList.size());Mockito.when(userMapperMock.toDto(user1)).thenReturn(userDto1);Mockito.when(userMapperMock.toDto(user2)).thenReturn(userDto2); //Mocking the toDto method.&nbsp;Mockito.when(userRepositoryMock.findAll(pageable)).thenReturn(userPage);assertThat(userService.findAll(pageable)).isEqualTo(userDtoPage);}现在，如果有更多的元素要添加到页面，我会对toDto所有元素进行相同的模拟。