Switching from Jmockit to mockito

Question

so I decided to move from jmockit to mockito and it seems strange to me I can't understand how some things work in mockito

I have that simple @BeforeEach method and when my objects are mocked I always get a null pointer exception

@Mock
public EntityManager entityManager;

@Mock
public TimerSessionBean timerSessionBean;

@Mock
public Client client;

private CaseSetReminder caseSetReminder;

private Request request;
private Message message;

@BeforeEach
final void beforeEach() {
    request = new Request();
    message = new Message();

    String spaceId = "SPACE_ID";
    String threadId = "THREAD_ID";

    caseSetReminder = new CaseSetReminder();
    caseSetReminder.entityManager = entityManager;
    caseSetReminder.timerSessionBean = timerSessionBean;

    ThreadM thread = new ThreadM();

    thread.setName("spaces/" + spaceId + "/thread/" + threadId + "");
    Sender sender = new Sender();
    sender.setName("MyName");
    message.setSender(sender);
    message.setThread(thread);

    Reminder reminder = new Reminder("Do Something", ZonedDateTime.now(ZoneId.of("Europe/Athens")).plusMinutes(10),
            "DisplayName", "Europe/Athens", spaceId, threadId);

    reminder.setReminderId(1);
    timerSessionBean.nextReminderDate = reminder.getWhen();
}

it always throws me

Argument passed to verify() is of type TimerSessionBean and is not a mock!

Make sure you place the parenthesis correctly!

See the examples of correct verifications:

verify(mock).someMethod();

verify(mock, times(10)).someMethod();

verify(mock, atLeastOnce()).someMethod();

but that's not true its timerSessionBean is mocked and my syntax is correct

and that's the method I run that triggers the beforeEach method

@Test
void mockitoTest() throws Exception {

    final String expectedDate = "12/12/2019 12:00 athens";
    message.setText("remind me ' set next reminder Test' at " + expectedDate);
    request.setMessage(message);

    // Already set in mock a nextReminder that is to be in 10 mins from now()
    //So this should not be set
    caseSetReminder.setRequest(request);
    caseSetReminder.setReminder();

    //Verifies that setNextReminder is called 0 times because Input reminderDate is AFTER the current
    verify(timerSessionBean , times(1)).setNextReminder(Mockito.any(Reminder.class), Mockito.any(ZonedDateTime.class));

}

I hope you guys can help me figure this out

Answer 1

You need to make sure you init the Mockito engine:

@BeforeEach
final void beforeEach() {
  MockitoAnnotations.initMocks(this);
  ..

or

 @RunWith(MockitoJUnitRunner.class) 
 public class TestClass{

also, you cannot set fields of a mocked class like:

timerSessionBean.nextReminderDate = reminder.getWhen();

try using doReturn(), when(), then() to configure behavior