[FIXED] spring controller test by mock service

Issue

Love Spring Testing Even More With Mocking and Unit Test Assistant:

A mocked service replaces multiple dependencies

enter image description here

@Controller
@RequestMapping("/people")
public class PeopleController {
    @Autowired
    protected PersonService personService;
    @GetMapping
    public ModelAndView people(Model model) {
        for (Person person: personService.getAllPeople()) {
            model.addAttribute(person.getName(), person.getAge());
        }
        return new ModelAndView("people.jsp", model.asMap());
    }
}

private MockMvc mockMvc:

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration
public class PeopleControllerTest {
    @Autowired
    PersonService personService;

    private MockMvc mockMvc;

    @Configuration
    static class Config {
        // Other beans
        @Bean
        public PersonService getPersonService() {
            return mock(PersonService.class);
        }
    }
    @Test
    public void testPeople() throws Exception {
        // When
        ResultActions actions = mockMvc.perform(get("/people"));
    }
}

I get a mistake when I want to run mockMvc

java.lang.NullPointerException

Solution

Perform the following steps:

1. create service mock instead of service original ("PersonServiceMock")

2. replace service original by service mock

       @Autowired
       PersonService personService;
   
       @Autowired
       PeopleController peopleController;
   
       private MockMvc mockMvc;
   
       @Before
       public void setup() {
       peopleController = new PeopleController(new personServiceMock());
       mvc = MockMvcBuilders.standaloneSetup(peopleController).build();
      }    
   
       @Configuration
       static class Config {
           // Other beans
           @Bean
           public PersonService getPersonService() {
               return mock(PersonService.class);
           }
       }
       @Test
       public void testPeople() throws Exception {
           // When
           ResultActions actions = mockMvc.perform(get("/people"));
       }
   }
   

Answered By - ismael