MapStruct：模拟嵌套映射器

Question

我使用 MapStruct 来映射我的实体，我正在使用 Mockito 模拟我的对象。

我想测试一个包含与 mapStruct 的映射的方法。 问题是嵌套映射器在我的单元测试中始终为空（在应用程序中运行良好）

这是我的映射器声明：

@Mapper(componentModel = "spring", uses = MappingUtils.class)
public interface MappingDef {
     UserDto userToUserDto(User user)
}

这是我的嵌套映射器

@Mapper(componentModel = "spring")
public interface MappingUtils {
    //.... other mapping methods used by userToUserDto

这是我要测试的方法：

@Service
public class SomeClass{
        @Autowired
        private MappingDef mappingDef;

        public UserDto myMethodToTest(){

        // doing some business logic here returning a user
        // User user = Some Business Logic

        return mappingDef.userToUserDto(user)
}

这是我的单元测试：

@RunWith(MockitoJUnitRunner.class)
public class NoteServiceTest {

    @InjectMocks
    private SomeClass someClass;
    @Spy
    MappingDef mappingDef = Mappers.getMapper(MappingDef.class);
    @Spy
    MappingUtils mappingUtils = Mappers.getMapper(MappingUtils.class);

    //initMocks is omitted for brevity

    @test
    public void someTest(){
         UserDto userDto = someClass.myMethodToTest();

         //and here some asserts
    }

mappingDef 注入正确，但mappingUtils 始终为空

Disclamer：这不是this question 的副本。他正在使用@Autowire，所以他正在加载弹簧上下文，所以他正在做集成测试。我正在做单元测试，所以我不使用@Autowired

我不想让mappingDef 和mappingUtils @Mock 所以我不需要在每个用例中都做when(mappingDef.userToUserDto(user)).thenReturn(userDto)

Answer 1

如果您愿意使用 Spring 测试工具，使用 org.springframework.test.util.ReflectionTestUtils 相当容易。

MappingDef mappingDef = Mappers.getMapper(MappingDef.class);
MappingUtils mappingUtils = Mappers.getMapper(MappingUtils.class);

...

// Somewhere appropriate
@Before
void before() {
    ReflectionTestUtils.setField(
        mappingDef,
        "mappingUtils",
        mappingUtils
    )
}

Answer 2

强制 MapStruct 使用构造函数注入生成实现

@Mapper(componentModel = "spring", uses = MappingUtils.class, injectionStrategy = InjectionStrategy.CONSTRUCTOR)
public interface MappingDef {
     UserDto userToUserDto(User user)
}

@Mapper(componentModel = "spring", injectionStrategy = InjectionStrategy.CONSTRUCTOR)
public interface MappingUtils {
    //.... other mapping methods used by userToUserDto

使用构造函数注入，以便您可以使用映射器构造被测类。

@Service
public class SomeClass{

        private final MappingDef mappingDef;

        @Autowired
        public SomeClass(MappingDef mappingDef) {
            this.mappingDef = mappingDef; 
        }

        public UserDto myMethodToTest(){

        // doing some business logic here returning a user
        // User user = Some Business Logic

        return mappingDef.userToUserDto(user)
}

测试 SomeClass。注意：它不是你在这里测试的映射器，所以可以模拟映射器。

@RunWith(MockitoJUnitRunner.class)
public class SomeClassTest {

    private SomeClass classUnderTest;

    @Mock
    private MappingDef mappingDef;

    @Before init() {
        classUnderTest = new SomeClass(mappingDef);
        // defaultMockBehaviour: 
when(mappingDef.userToUserDto(anyObject(User.class).thenReturn(new UserDto());
    } 

    @test
    public void someTest(){
         UserDto userDto = someClass.myMethodToTest();

         //and here some asserts
    }

在真正的单元测试中，也要测试映射器。

@RunWith(MockitoJUnitRunner.class)
public class MappingDefTest {

  MappingDef classUnderTest;

  @Before
  void before() {
       // use some reflection to get an implementation
      Class aClass = Class.forName( MappingDefImpl.class.getCanonicalName() );
      Constructor constructor =
        aClass.getConstructor(new Class[]{MappingUtils.class});
      classUnderTest = (MappingDef)constructor.newInstance( Mappers.getMapper( MappingUtils.class ));
  }

  @Test
  void test() {
     // test all your mappings (null's in source, etc).. 
  }

Answer 3

所以，试试这个：

马文：

      <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-beans</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <scope>test</scope>
        </dependency>

@ComponentScan(basePackageClasses = NoteServiceTest.class)
@Configuration
public class NoteServiceTest {

    @Autowired
    private SomeClass someClass;
    private ConfigurableApplicationContext context;

    @Before
    public void springUp() {
        context = new AnnotationConfigApplicationContext( getClass() );
        context.getAutowireCapableBeanFactory().autowireBean( this );
    }

    @After
    public void springDown() {
        if ( context != null ) {
            context.close();
        }
    }

    @test
    public void someTest(){
         UserDto userDto = someClass.myMethodToTest();

         //and here some asserts
    }

更好的是一直使用构造函数注入...同样在SomeClass 和使用@Mapper(componentModel = "spring", injectionStrategy = InjectionStrategy.CONSTRUCTOR).. 然后你就不需要在你的测试用例中使用弹簧/弹簧模拟了。