How to use SpyingOnRealObjectsTest class of org.mockitousage.spies package

This question is ancient, but Mockito v2.1.0+ now has a built-in feature for this.

verify(mock, description("This will print on failure")).someMethod("some arg");

More examples included from @Lambart's comment below:

verify(mock, times(10).description("This will print if the method isn't called 10 times")).someMethod("some arg");
verify(mock, never().description("This will print if someMethod is ever called")).someMethod("some arg");
verify(mock, atLeastOnce().description("This will print if someMethod is never called with any argument")).someMethod(anyString());

Cleaner version:

@RunWith(MockitoJUnitRunner.class)
public class CorrectionServiceTest {

    private static final Long VALID_ID = 123L;

    @Mock
    AddressDao addressDao;

    @InjectMocks
    private CorrectionService correctionService;

    @Test
    public void shouldCallDeleteAddress() { 
        //when
        correctionService.correct(VALID_ID);
        //then
        verify(addressDao).deleteAddress(VALID_ID);
    }
}

You need to create a MOCK of pcUserService first, and then use that mock.

PcUserService mock = org.mockito.Mockito.mock(PcUserService.class);
when(mock.read("1")).thenReturn(pcUser);

I think you do need to cast it, but it shouldn't be too bad:

Foo<Bar> mockFoo = (Foo<Bar>) mock(Foo.class);
when(mockFoo.getValue()).thenReturn(new Bar());

"Mock" your repository method calls. Also, use @InjectMocks instead @Autowired for TransactionService. And you can also use MockitoJUnitRunner. How to mock repository calls:

when(customerRepository.save(sender)).thenReturn(someSenderInstance);

To verify that mocked method call has been invoked use:

verify(customerRepository, times(1)).save(sender);

Also, remember one thing: You are testing services! Therefore, all calls to database should be mocked.

You can use MockingDetails and either printInvocations or getInvocations to inspect the interactions belonging to a mock. However, this will not produce a list of invocations belonging to multiple mocks in the order that happened: just interactions with each individual mock.

Code snippet, as contributed by elhefe and Anand Rockzz:

import static org.mockito.Mockito.mockingDetails;

System.out.println(mockingDetails(mock).printInvocations());
/* or */
System.out.println(mockingDetails(mock).getInvocations());

Acknowledging your reluctance and caveats in the comments, I would say that this is a technique that does more to lock in your current implementation than to analyze your real constraints and prevent regressions. Furthermore, if your algorithm has a lot of interactions with direct collaborators, that might be an indication that the algorithm should be refactored.

If the system is untested or undocumented legacy code, this might be a practical way to programmatically generate a regression test or analysis--a temporary starting point for more-informed regression testing--but in your shoes I would instead start by documenting the contract of each component and then writing a test that confirms those interactions and constraints. Mockito recommendations (as intimated through this article by Mockito's original developer) tend toward adding stubs until tests pass and adding verifications/counts only where there are expensive or non-idempotent side effects.

You can implement this test functionality this way (Java 8):

myMock
    .expect(requestTo("http://myfakeurl.blabla"))
    .andExpect(method(HttpMethod.GET))
    .andRespond(request -> {
        try {
            Thread.sleep(TimeUnit.SECONDS.toMillis(1));
        } catch (InterruptedException ignored) {}
        return new MockClientHttpResponse(myJsonResponse, HttpStatus.OK);
    });

But, I should warn you, that since MockRestServiceServer simply replaces RestTemplate requestFactory any requestFactory settings you'd make will be lost in test environment.

As per InputStream.readAllBytes() method javadoc this method was introduced in Java 9.

Since:

9

It won't work when the code is compiled on lower Java version, in your case Java 8.

Difference between a Spy and a Mock

When Mockito creates a mock – it does so from the Class of a Type, not from an actual instance. The mock simply creates a bare-bones shell instance of the Class, entirely instrumented to track interactions with it. On the other hand, the spy will wrap an existing instance. It will still behave in the same way as the normal instance – the only difference is that it will also be instrumented to track all the interactions with it.

In the following example – we create a mock of the ArrayList class:

@Test
public void whenCreateMock_thenCreated() {
    List mockedList = Mockito.mock(ArrayList.class);

    mockedList.add("one");
    Mockito.verify(mockedList).add("one");

    assertEquals(0, mockedList.size());
}

As you can see – adding an element into the mocked list doesn’t actually add anything – it just calls the method with no other side-effect. A spy on the other hand will behave differently – it will actually call the real implementation of the add method and add the element to the underlying list:

@Test
public void whenCreateSpy_thenCreate() {
    List spyList = Mockito.spy(new ArrayList());
    spyList.add("one");
    Mockito.verify(spyList).add("one");

    assertEquals(1, spyList.size());
}

Here we can surely say that the real internal method of the object was called because when you call the size() method you get the size as 1, but this size() method isn’t been mocked! So where does 1 come from? The internal real size() method is called as size() isn’t mocked (or stubbed) and hence we can say that the entry was added to the real object.

Source: http://www.baeldung.com/mockito-spy + self notes.