@WebMvcTest content is null

Question

I've already read this Q&A but it didn't solve the problem. I'm using Spring Boot 1.4.2.RELEASE and I'm attempting to speed up my tests. Up to this point, I've used @SpringBootTest and I'm testing switching some of these simpler tests to @WebMvcTest.

My controller has the following method which is responding to GET requests.

public ResponseEntity<MappingJacksonValue> fetchOne(@PathVariable Long id, @RequestParam(value = "view", defaultValue = "summary", required = false) String view) throws NotFoundException {
    Brand brand = this.brandService.findById(id);

    if (brand == null) {
        throw new NotFoundException("Brand Not Found");
    }

    MappingJacksonValue mappingJacksonValue = jsonView(view, brand);
    return new ResponseEntity<>(mappingJacksonValue, HttpStatus.OK);
}

My test looks like this:

@RunWith(SpringRunner.class)
@WebMvcTest(BrandController.class)
public class BrandSimpleControllerTest {

    @Autowired
    private MockMvc mockMvc;

    @MockBean
    private BrandService brandService;

    @Test
    public void testExample() throws Exception {
        Brand brand = new Brand(1l);
        brand.setName("Test Name");
        brand.setDateCreated(new Date());
        brand.setLastUpdated(new Date());

        when(this.brandService.findById(1l)).thenReturn(brand);

        this.mockMvc.perform(get("/api/brands/1").accept(MediaType.APPLICATION_JSON))
                .andExpect(status().isOk())
                .andExpect(jsonPath("$.name", is("Test Name")));
    }
}

When I run this test, I get nothing back in the content. I'm not doing anything significantly different than this guide, so not sure what I'm missing.

I should note that using @SpringBootTest with the exact same controller works as expected.