如何在春季服务中模拟映射映射器输出？

Question

我有使用映射映射器（Custommapstruct -Mapper）的春季服务（MyService）：

@Service
public class MyService {

    private final ClassA classA;
    private final ClassB classB;
    /*
    other private fields declarations...
    */

    private CustomMapstructMapper customMapstructMapper = Mappers.getMapper(CustomMapstructMapper.class);

    //MyService constructor

    public MyService(final ClassA classA, etc...) {

        this.classA = classA;
        //etc...

    }

    public ServiceOutput mainMethod(some parameters) {

        //some business logic


        MyMapperOutput myMapperOutput = customMapstructMapper.map(MapperParameter parameter);

        ServiceOutput serviceOutput = some business logic with myMapperOutput;

        return serviceOutput;

    }

} 

我想单元测试MyService（我使用Junit 5），并模拟我的Custmapsstrumpstructmapper 输出，而无需在测试期间调用真实映射器执行。我已经有另一个测试类，该类特定于Custompaps -Mapper中测试所有自定义映射。

因此，我有一个测试课：

@ExtendWith(MockitoExtension.class)
class MyServiceTest {

    @InjectMocks
    private MyService myService;

    @Mock
    private CustomMapstructMapper customMapstructMapper;

    @Mock
    private MyMapperOutput myMapperOutput;

    @Test
    void testMyService() {
        /*
        Some mocks creation ..
        */

        Mockito.when(myMapperOutput.getSomeField()).thenReturn("Some value");
        Mockito.when(customMapstructMapper.map(Mockito.any(MapperParameter.class))).thenReturn(myMapperOutput);

        ServiceOutput serviceOutput = myService.mainMethod(some parameters);

        /*
        Some assertions on serviceOutput
        */

    }

} 

当我运行测试时，我的Mapper Custommaps -Mapperimpl的实现在MyService中被调用，而不是我的模拟。 由于某些字段没有启动，因此在我的映射器中抛出了NullPoInterException。 我试图通过实现我的映射映射器创建一个模拟：

@Mock private CustomMapstructMapperImpl customMapstructMapper;

但是我得到了相同的结果。

我在做什么错？

Answer 1

您没有利用春季框架和对其进行映射支持。

在您的服务更改中：

private CustomMapstructMapper customMapstructMapper = Mappers.getMapper(CustomMapstructMapper.class);

则会

@Autowired
private CustomMapstructMapper customMapstructMapper;

如果您尚未使用映射器，

@Mapper( componentModel = "spring" )

导致生成的映射器具有@component从弹簧框架上注释，并且可以自动使用。这。

进行这些更改后，您提供测试模拟的方法应该有效。

Answer 2

下面的代码正常工作。所以也许还有其他事情发生了。您的代码示例还不够完整。

@ExtendWith(MockitoExtension.class)
public class TestForService {

    @InjectMocks
    private Service service;

    @Mock
    private Mapper mapper;

    @Test
    public void test_service() {
        System.out.println("test_service start");
        Mockito.when(mapper.doSomeTh()).thenReturn("mock mapper doSomeTh");
        String result = service.service();
        System.out.println("test_service end, result: " + result);
    }

    static class Service {
        private Mapper mapper = Mapper.getMapper();

        public String service() {
            System.out.println("Service.service");
            return mapper.doSomeTh();
        }

        public void setMapper(Mapper mapper) {
            this.mapper = mapper;
            System.out.println("Service.setMapper: " + mapper);
        }
    }

    static class Mapper {

        public String doSomeTh() {
            System.out.println("Mapper.doSomeTh");
            return "mapper end";
        }

        public static Mapper getMapper() {
            System.out.println("Mapper.getMapper");
            return null;
        }
    }
}

结果：

Mapper.getMapper
Service.setMapper: mapper
test_service start
Service.service
test_service end, result: mock mapper doSomeTh

Answer 3

在这里简单的方法：
只需在MyService中添加package-Provate setter方法

// for testing only
void CustomMapstructMapper setCustomMapstructMapper(CustomMapstructMapper mapper) {
    this.customMapstructMapper = mapper;
}

，然后在测试代码中注入模拟的custommapsstructmapper

@Test
void testMyService() {
    /*
    Some mocks creation ..
    */

    Mockito.when(myMapperOutput.getSomeField()).thenReturn("Some value");
    Mockito.when(customMapstructMapper.map(Mockito.any(MapperParameter.class))).thenReturn(myMapperOutput);

    myService.setCustomMapstructMapper(customMapstructMapper); // inject your mocked customMapstructMapper here

    ServiceOutput serviceOutput = myService.mainMethod(some parameters);

    /*
    Some assertions on serviceOutput
    */

}