#WebMvcTest content is null - spring

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.