Is there anything similar to Junit Setup Method in Mockito

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.

Answer 2

You can create an AbstractTestCase class that is abstract and is extended by all test cases where you need this mock. In that abstract test case, you will have the following statements.

 @Ignore // just in case your runner thinks this is a JUnit test.
 public abstract class AbstractTestCase
 {
      @Mock
      private DAO mockDAO;

      @Before
      private void setupMocks()
      {
           when(mockDAO.a()).thenReturn("test")
           ....
      }
 }

In your concrete test case classes, you would

 public class MyConcreteTestCase extends AbstractTestCase
 {
      @InjectMocks
      @Autowired
      private DAOProcess daoProcess;

      ....
 }