Preperate data with MockMVC for GET method

Question

I'am trying to test my get all events method. So i'm trying to first fill one event into database and then perform get method by MockMVC. But it is returning empty content.

I have tried to change specific annotations such like MockBean/Autowired on eventService. Also tried to change annotations on test class. Event controller has these 3 annotations:

@RequestMapping("/event")
@CrossOrigin
@RestController

Method to add event

public void addEvent(final Event event)
    {
        eventRepository.save(event);
    }

Method to get events

public Iterable<Event> getAll()
{
        return eventRepository.findAll();
}

Test for get method

@SpringBootTest
@AutoConfigureMockMvc
class EventControllerTest extends Specification {

    @MockBean
    private EventService eventService

    @Autowired
    private MockMvc mockMvc

    def "whet get is performed on all endpoint the response has status 200"()
    {

        given:
             eventService.addEvent(new Event(new Date(), "type", "league", "team", "msg"))

         expect: "the status is 200"

         when:
              ResultActions resultActions = mockMvc.perform(get("/event/all"))

I expect to get method return one event but actual it returns 0.