How to use prevents_across_jvm_serialization_with_constructor method of org.mockitousage.constructor.CreatingMocksWithConstructorTest class

If this is really a maven project and you are using matching m2e-version 1.9, it should automatically configure the "Contains test sources."-setting and the related settings correctly.

You may have to update the project classpath by right-clicking on the project and Choosing "Maven" > "Update Project"

How about

when( method-call ).thenReturn( value1, value2, value3 );

You can put as many arguments as you like in the brackets of thenReturn, provided they're all the correct type. The first value will be returned the first time the method is called, then the second answer, and so on. The last value will be returned repeatedly once all the other values are used up.

It really depends on GeneralConfigService#getInstance() implementation. Also you can simplify your test code a lot if you use @InjectMocks annotation.

When using MockitoJUnitRunner you don't need to initialize mocks and inject your dependencies manually:

@RunWith(MockitoJUnitRunner.class)
public class GeneralConfigServiceImplTest  {

    @InjectMocks
    private GeneralConfigService generalConfigService;

    @Mock
    private GeneralConfigDAO generalConfigDAO;

    @Test
    public void testAddGeneralConfigCallDAOSuccess() {
       // generalConfigService is already instantiated and populated with dependencies here
       ...
    }
}

Here is a complete example.

The code is almost like your original (just simplified better test validation):

public enum MyEnum {A, B}

public class Bar {

    public int foo(MyEnum value) {
        switch (value) {
            case A: return 1;
            case B: return 2;
        }
        throw new IllegalArgumentException("Do not know how to handle " + value);
    }
}

And here is the unit test with full code coverage, the test works with Powermock (1.4.10), Mockito (1.8.5) and JUnit (4.8.2):

@RunWith(PowerMockRunner.class)
public class BarTest {

    private Bar bar;

    @Before
    public void createBar() {
        bar = new Bar();
    }

    @Test(expected = IllegalArgumentException.class)
    @PrepareForTest(MyEnum.class)
    public void unknownValueShouldThrowException() throws Exception {
        MyEnum C = mock(MyEnum.class);
        when(C.ordinal()).thenReturn(2);

        PowerMockito.mockStatic(MyEnum.class);
        PowerMockito.when(MyEnum.values()).thenReturn(new MyEnum[]{MyEnum.A, MyEnum.B, C});

        bar.foo(C);
    }

    @Test
    public void AShouldReturn1() {
        assertEquals(1, bar.foo(MyEnum.A));
    }

    @Test
    public void BShouldReturn2() {
        assertEquals(2, bar.foo(MyEnum.B));
    }
}

Result:

Tests run: 3, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.628 sec

Well mockito mocks works by extending the class and overriding the method, which in your case is not possible on A.a(String). If you want this to happen you have to remove the final modifier.

Now assuming A.a(String) is not final, what you ask is completely doable with mockito:

given(mockA.a(anyString()).willAnswer(returnOfB(bInstance));

Answer<String> returnOfB(final B bInstance) {
    return new Answer<String>() {
         public String answer(Invocation invocation) {
             String arg = (String) invocation.getActualArguments()[0];
             return bInstance.b(arg);
         }
    };
}

Please note this answer has been written on a phone and might have typo, or wrong names, though you should get the idea of what should be done to achieve what you want.

Cheers

I looked up the source code of LogManager.class and found the reason was there's no LoggerContextFactory found in log4j-provider.properties which should be found in log4j-core.jar/META-INF.
So check your log4j-core.jar/META-INF/log4j-provider.properties file , or you can delete your log4j-core.jar in your local repository.

You setup your mock to return something when it receives a given device objet:

        Device device = new Device() ;
        Mockito.when(deviceDao.save(device)).thenReturn(deviceEntity);

This tells your deviceDao mock to return deviceEntity when it receives device as a parameter to the save method.

Mockito uses equals for argument matching. This means that if you call deviceDao.save(x), deviceEntity will be returned if x.equals(device) is true.

Your method:

public String  show(){
        Device device = new Device() ;
        device.setContactName("abc");
        Device deviceEntity = deviceDao.save(device);
        System.out.println(deviceEntity);  // i get this null always Why ???
        return "demo";
}

This calls save() on a new Device instance. I highly doubt that this device is equal to the one you setup your mock with.

One way to solve this is to use a broader matcher in your test:

Mockito.when(deviceDao.save(any(Device.class)).thenReturn(deviceEntity);

Or simply to ensure that the Device that you setup your mock with is the same as the one used in your code. I can't provide you with an example since your question does not include the code for Device.equals().

Yes, you can. The trick here is that you have to get to the instance of the lambda that is passed to the registerMessage and then execute that expression and then you can verify the result.

For the purpose of a meaningful example I created this Handler class that contains the dispatchMessage that you want to test:

public class Handler {

    private Dispatcher dispatcher = new Dispatcher();

    public void dispatchMessage(MessageHandler handler, String argument1, String argument2, Long argument3) {

        handler.registerMessage(() -> {
            dispatcher.dispatch(argument1,
                    argument2,
                    argument3);
        });

    }

    interface MessageHandler {
        void registerMessage(Runnable run);
    }

    static class Dispatcher {
        void dispatch(String a, String b, long c){
            // Do dispatch
        }
    }
}

What you have to remember is that a lambda expression is just a short hand form to pass a function to a method. In this example the function is the run method of a Runnable. Therefore the method registerMessage of the interface for MessageHandler takes a Runnable as it's argument. I also included an implementation for the Dispatcher, which is called from within registerMessage. The test for this looks like this:

@RunWith(MockitoJUnitRunner.class)
public class HandlerTest {
    @Mock
    private Dispatcher dispatcher;
    @InjectMocks
    private Handler classUnderTest;
    @Captor
    private ArgumentCaptor<Runnable> registerMessageLambdaCaptor;

    @Test
    public void shouldCallDispatchMethod() {
        final String a = "foo";
        final String b = "bar";
        final long c = 42L;

        MessageHandler handler = mock(MessageHandler.class);

        classUnderTest.dispatchMessage(handler, a, b, c);

        verify(handler).registerMessage(registerMessageLambdaCaptor.capture());

        Runnable lambda = registerMessageLambdaCaptor.getValue();

        lambda.run();

        verify(dispatcher).dispatch(a, b, c);
    }
}

There is an ArgumentCaptor for the lambda expression which we use in the first verification of the registerMessage. After that verification we can retrieve the lambda expression from the captor. The type of the lambda expression is Runnable, as defined in the MessageHandler interface. Hence we can call the run method on it and then verify that the dispatch method on the Dispatcher was called with all the appropriate arguments.

This stub is wrong :

doNothing().when(mockObject.methodToStub(captor.capture())); // wrong

methodToStub(...) must be outside the when if using this API style (it should only contain the mock) :

doNothing().when(mockObject).methodToStub(captor.capture()); // correct

Tho remarks however :

1. doNothing is the default for void methods for a mock.
2. You can use the BDDMockito aliases that enables your code to be real à la Behavior Driven Development