I am trying to test my springboot controller /save endpoint. I want to test that if you send a json request with a null agency name you should get back a 400 status and the response “Agency Name cannot be null.”
This works during local testing with postman, but I haven’t been able to get it working in junit.

Heres my code

jUnit:

@SpringBootTest
@AutoConfigureMockMvc
@WithMockUser(username = "test", password = "test", authorities = { "ANY " })
public class AgencyControllerIT {

    @Autowired
    private MockMvc mvc;

    @Mock
    private AgencyRepository mRepository;

    @MockBean
    private AgencyService mService;
        
        @Test
    public void testControllerSaveWithoutAgencyName() throws Exception {
        // Create JSON
        String body = "[{" +
                ""agency": null," +
                ""type": "Type"," +
                ""defaultText": "DefaultText""
                "}]";

        //Perform request to endpoint and assert bad request
        this.mvc.perform(MockMvcRequestBuilders.post("/myApplication/save")
                        .contentType(MediaType.APPLICATION_JSON)
                        .content(body))
                .andDo(print())
                .andExpect(status().isBadRequest())
                .andExpect(content().string("Agency Name cannot be null"))
                .andReturn();
        //Verify service is not called
        verify(mService, times(0)).merge(any());
    }

It gives me this response

MockHttpServletRequest:
      HTTP Method = POST
      Request URI = /myApplication/save
       Parameters = {}
          Headers = [Content-Type:"application/json;charset=UTF-8"]
             Body = [{"agency:" null, "type": "Type","defaultText": "DefaultText"}]
    Session Attrs = {}

MockHttpServletResponse:
           Status = 200
    Error message = null
          Headers = [Vary:"Origin", "Access-Control-Request-Method", "Access-Control-Request-Headers", Content-Type:"application/json", X-Content-Type-Options:"nosniff", X-XSS-Protection:"0", Cache-Control:"no-cache, no-store, max-age=0, must-revalidate", Pragma:"no-cache", Expires:"0", X-Frame-Options:"DENY"]
     Content type = application/json
             Body = [ ]
    Forwarded URL = null
   Redirected URL = null
          Cookies = []

java.lang.AssertionError: Status expected:<400> but was:<200>
Expected :400
Actual   :200

While debugging, I did notice something interesting in the controller.

My controller checks using a custom method called postFieldValidation

Controller

    @Transactional
    @PostMapping(value = {"/save"}, produces = {"application/json"})
    public ResponseEntity<List<Agency>> save(@RequestBody List<Agency> updatedValues){
        String message = agencyService.postFieldValidation(updatedValues);
        if(message != null){
            return new ResponseEntity(message, HttpStatus.BAD_REQUEST);
        }
        List<Agency> result = agencyService.merge(updatedValues);
        return new ResponseEntity<>(result, HttpStatus.OK);
    }

Post field Validation inside service

public String postFieldValidation(List<Agency> updatedValues) {
        String message = null;
        for (Agency updatedValue : updatedValues) {
            if (updatedValue.getAgency() == null)
                message = "Agency name cannot be null";
            else if (updatedValue.getDefaultText() == null)
                message = "Default Text cannot be null";
        }
        return message;
    }

I noticed that updatedValues has the proper definition inside of the controller, but inside of the service it is null and skips the validation.