Question

I have the following scenario

 interface DAO
 {
      String a();
      String b();
      String c();

 }

I create a mock of this DAO interface and I feed it to something called DAOProcess. Inside DAOProcess, I have various methods calling DAO methods a, b and c.

Now each time I need to unit test a method in DAOProcess, I’ll end up writing when(mockDAO.a()).thenReturn("test").

Is there anyway I can move these when(mockDAO.a()).thenReturn("test") common to all the test cases ?

Answer 1

If your test cases are all in one class you could make use of a method annotated with @Before, e.g.:

...
private DAO mockDAO;

@Before 
public void setUp() {
    mockDAO = mock(DAO.class);
    when(mockDAO.a()).thenReturn("test");
    ...etc...
}    
...

Or, if you need the behaviour over many test classes you could write a utility class to set behaviour on a Mock instance, e.g.:

public class MockDAOPrototype {
    public DAO getMockWithDefaultBehaviour() {
        final DAO mockDAO = mock(DAO.class);
        when(mockDAO.a()).thenReturn("test");
        ...etc...

        return mockDAO;
    }
}

And then call MockDAOPrototype.getMockWithDefaultBehaviour() in your setUp method.