I have a service A. A uses a repository R and a service B. B executes REST calls. R and B are injected through the constructor (as it is recomended) of A. I now want to test a method, where both R and B are invoked. But I only want to mock B, as the test database is filled with a lot of test data and I want to use that. I am not able so far to achive this correct injection with Mockito. Here is my code:

@Service class A {
    private final R repo;
    private final B service;

    @Autowired
    public A(R repo, B service) {
        this.repo = repo;
        this.service = service;
    }

    public int foo() {
        repo.doSomeStuff();
        service.doSomeStuff();
        ...
    }
}

@SpringBootTest
@ExtendWith(MockitoExtension.class)
class ATest {
    @Autowired A service;
    @Mock B mockedService;

    @BeforeEach
    void setupMocks() {
        MockitoAnnotations.openMocks(this);
    }

    @Test
    void testFoo() {
        service.foo();
        ...
    }
}

I already played around with different variations of also using @InjectMocks on ATest.service and also leaving out the @Autowired. Nothing worked so far. Is it even possible? Do I maybe need to use setter injection in A?

CodePudding user response：

You are making things way too complex. Use @MockBean and Spring Boot will do the rest. Rewrite your test to the following

@SpringBootTest
class ATest {
    @Autowired A service;
    @MockBean B mockedService;

    @Test
    void testFoo() {
        service.foo();
        ...
    }
}

That is it, nothing more, nothing less. Spring will now use the mocked dependency and inject it into the service.

For more information on testing with Spring Boot I strongly suggest a read of the Testing section in the reference guide. It also has a whole section on mocking when using Spring Boot and testing.