Mockito Hints

Index

• Setup method calls on Autowired interfaces
• Verify generic method calls
• Matchers
• Resetting a specific mock for every JUnit test
• Mockito, JUnit and Spring Boot

Setup method calls on Autowired interfaces

Given an autowired item inside a test running with the SpringJUnit4ClassRunner follow this simple syntax.

Instead of the Mockito.any, is possible to insert directly the value of the object.

    @Autowired
    private RestOperations restTemplate;

    @Test
    private void testSomething()
    {
        ...
        
        Mockito.when(restTemplate.postForObject(
                Mockito.any(String.class),
                Mockito.any(Map.class),
                Mockito.any(Class.class)
            )).thenReturn(response);
    }

Verify generic method calls

The matchers can be used also to verify if the method was called (as the calls on autowired)

    @Test
    private void testSomething()
    {
        ...
        
        verify(restTemplate, times(1)).postForObject(
                Mockito.any(String.class),
                Mockito.any(Map.class),
                Mockito.any(Class.class));
    }

Matchers

The matchers can be expressed in various ways. In case a matcher should match a template based value, then the square brackets syntax should be used!!

    Mockito.any(String.class);
    Mockito.<String>any();
    Mockito.anyString();
    Mockito.anyInt();

To match for equality differences, etc

    Mockito.eq("Value to verify against");

Resetting a specific mock for every JUnit test

The specific item that had been mocked can be resetted to initial state

    @Autowired
    private RestOperations restTemplate;

    @Before
    public void initializeTarget() {
        ...
        Mockito.reset(restTemplate);
    }

Mockito, JUnit and Spring Boot

It is possible to use the autowired annotation as with spring. This is for SpringBoot & Spring 4.

//run with Spring context
@RunWith(SpringJUnit4ClassRunner.class)
//load the configuration through the standard spring boot application class
@SpringApplicationConfiguration(classes = LvmConfigurationServiceApplication.class)
public class AlarmConfigServiceTest {
    //This object (not an interface) is the target of our tests.
    //It will be filled by Spring
    @Autowired
    //the mocks will be injected automatically in it.
    @InjectMocks
    private AlarmConfigService target;

    //This class will be mocked
    @Mock
    private QueryTemplateService queryTemplate;

    //This method will reset and initalize all mocks for
    //each test run
    @Before
    public void setupTarget() {
        MockitoAnnotations.initMocks(this);
    }

    @Test
    public void doTest() {
         // ....
    }
}

Last modified on: January 03, 2016