Mockito @InjectMocks Strategy

Question

Yes, I know, much has been written about Mockito's @InjectMocks, but there is still a problem I haven't been able to solve...

Let's assume we have a class with four members...

class A {

    public B b1;
    public B b2;
    public B b3;
    public B b4;

}

...with B being an empty interface ...

interface B {

}

...then this setup will fail to initialize properly:

class MyTest {

    @InjectMocks
    private A a;

    @Mock(name = "b2")
    private B b2;  // will correctly be injected into field b2

    @Mock(name = "b4")
    private B b4;  // will be injected into field b3

    @Before
    public void init() {
        MockitoAnnotations.initMocks( this );
    }

    // some test here

}

Why? I have debugged the whole thing and found that it goes this way...

1. Search for a proper mock for field b1 . Two candidates found with suitable types, so look for names. None of the names match. End. b1 is empty, correct.
2. Search for a proper mock for field b2 . Two candidates found with suitable types, so look for names. One of the names match. b2 is filled correctly with the mock "b2".
3. Search for a proper mock for field b3 . Only one candidate ("b4") is found with suitable types, so use that one. b3 is incorrectly filled with mock "b4".
4. No mock left for field b4 , will remain empty (incorrectly).

So, the only solution would be to add always one mock more than needed (so that for all needed mocks, there's always at least 2 candidates):

@Mock(name = "fakeyMcFakeFake")
private B fakeyMcFakeFake;

( Of course, fakeyMcFakeFake will be injected into field b1 in the second pass, but at least the other fields will be filled with the correct mocks ). But can this really be a solution? Has anyone an idea why this isn't handled better or how to handle it better?

( As for the use case... I have a controller that has various textboxes, etc. as members (those will be injected in the live code), obviously many of them are of the same type but for each test I will only need a small number of them.)

Answer 1

This has been fixed in pull request #215 (see release notes ). I suspect your code is about an older version of mockito.

While I like powermock I would advise to design code in a way that testing with mocks don't rely on powermock.

Also for powermock, either upgrade to version 1.6.4 (just released) ; there's an issue ( #14 ) on powermock github repository that changes the dependency to mockito-core . Otherwise please exclude mockito-all when declaring powermock dependency, mockito-all is a dependency for non-maven users (that still use the central repository). However I'm not sure future mockito 2.x beta will be compatible with current (1.6.x) powermock version.