How to mock autowired dependencies in Spring Boot MockMvc Unit tests?

Question

I am expanding upon the basic Spring Boot examples, adding an "autowired" repository dependency to my controller. I would like to modify the unit tests to inject a Mockito mock for that dependency, but I am not sure how.

I was expecting that I could do something like this:

@RunWith(SpringJUnit4ClassRunner.class)
@SpringApplicationConfiguration(classes = MockServletContext.class)
@WebAppConfiguration
public class ExampleControllerTest {

    private MockMvc mvc;

    @InjectMocks
    ExampleController exampleController;

    @Mock
    ExampleRepository mockExampleRepository;

    @Before
    public void setUp() throws Exception {
      MockitoAnnotations.initMocks(this);
    mvc = MockMvcBuilders.standaloneSetup(new ExampleController()).build();
    }

    @Test
    public void getExamples_initially_shouldReturnEmptyList() throws Exception {
        mvc.perform(MockMvcRequestBuilders.get("/example").accept(MediaType.APPLICATION_JSON))
                .andExpect(status().isOk())
                .andExpect(content().string(equalTo("[]")));
    }
}

but it doesn't inject the mock into the MockMvc. Can anyone explain how to do this with @Autowired dependencies, rather than constructor arguments?

Answer 1

Please use @RunWith(MockitoJUnitRunner.class) instead of @RunWith(SpringJUnit4ClassRunner.class) and you have to use the ExampleController exampleController; field with the injected mocks instead of creating a new one in line mvc = MockMvcBuilders.standaloneSetup(new ExampleController()).build();