Verify if inherited super class method was called from method being tested or not

Question

Ok so I'm stuck with Mockito again. Here's the situation:

I've a super class, and a subclass:

class Parent {
    protected void insertData() { 
        // Here is some database related stuff
        someObject.storeData();
    }
}


class Child extends Parent {

    private String name;

    public void printHierarchy(int x) {
        if (x > 1) {
            insertData()
        } else {
            System.out.println("Child");
        }

    }
}

And in my unit test class, I'm testing Child class printHierarchy() method:

@RunWith(SpringJUnit4ClassRunner.class)
public class ChildTest {

    @InjectMocks  // To inject mock objects
    private Child child = new Child();    

    @Before
    public void setUp() {
        MockitoAnnotations.initMocks(this);
        // This is where the issue is
        doNothing().when(child).insertData();
    }

    @Test
    public void testPrintHierarchy() {
        child.printHierarchy(5);
        // Here also
        verify(child, times(1)).insertData();
    }
}

So the issue is, how do I verify if insertData() method was called from Child#printHierachy()?

When I try the above code, I get the error as:

Argument passed to when() is not a mock!

Of course, child is not a mock. I'm testing that class. But how do I resolve this issue?

No I haven't found any duplicate of this. One question was pretty similar though, but it didn't help me.

Answer 1

You need to use spy() for that. The following code works:

public final class Bin
{
    @Test
    public void spyMe()
    {
        final Child c = spy(new Child());
        doNothing().when(c).printParent();
        c.printHierarchy(1);
        verify(c).printParent();
    }
}

class Parent {
    protected void printParent() { System.exit(0);}
}

class Child extends Parent {

    private String name;

    public void printHierarchy(int i) {
        if (i > 0)
            printParent();
    }
}

Answer 2

I think you need to use a spy for Child instead of a mock.