How to use createArgumentsAreDifferentException_withJUnit3_2x method of org.mockito.internal.junit.ExceptionFactoryTest class

The lombok @Slf4j annotation injects code into your class at compile time. Specifically, it will add the following code to your class:

private static final org.slf4j.Logger log =
                        org.slf4j.LoggerFactory.getLogger(LogExample.class);

@InjectMocks is telling Mockito to create an instance of your class and inject mocks as its dependencies at runtime.

The logger is injected at compile time. Dependecies are injected at runtime. That's why your logger is not mocked and cannot be mocked like this. If you look at the injected logger code above, you will understand, that the only way to mock the logger is to mock the LoggerFactory (Mockito can mock static methods since version 3.4, IIRC) and make it return the logger mock.

NB: Making mocks return mocks is usually a bad idea and should be avoided. @Slf4j is too convenient to not be used. It's a tradeoff.

NB: If all you want it silencing the logger, then you could also just configure it to shut up in your tests.

You can just write

verify(service).perform((Collection<String>) Matchers.argThat(contains("a", "b")));

From the compiler's point of view, this is casting an Iterable<String> to a Collection<String> which is fine, because the latter is a subtype of the former. At run time, argThat will return null, so that can be passed to perform without a ClassCastException. The important point about it is that the matcher gets onto Mockito's internal structure of arguments for verification, which is what argThat does.

You can do it with Mockito and PowerMockito.

Say you have ClassUnderTest with a constructor

public class ClassUnderTest {
    String name;
    boolean condition;

    public ClassUnderTest(String name, boolean condition) {
       this.name = name;
       this.condition = condition;
       init();
    }

    ...
}

And another class that calls that constructor

public class MyClass {

    public MyClass() { } 

    public void createCUTInstance() {
       // ...
       ClassUnderTest cut = new ClassUnderTest("abc", true);
       // ...
    }

    ...
}

At the Test class we could...

(1) use PowerMockRunner and cite both target classes above in the PrepareForTest annotation:

@RunWith(PowerMockRunner.class)
@PrepareForTest({ ClassUnderTest.class, MyClass.class })
public class TestClass {

(2) intercept the constructor to return a mock object:

@Before
public void setup() {
    ClassUnderTest cutMock = Mockito.mock(ClassUnderTest.class);
    PowerMockito.whenNew(ClassUnderTest.class)
                .withArguments(Matchers.anyString(), Matchers.anyBoolean())
                .thenReturn(cutMock);
}

(3) validate the constructor call:

@Test
public void testMethod() {
    // prepare
    MyClasss myClass = new MyClass();

    // execute
    myClass.createCUTInstance();

    // checks if the constructor has been called once and with the expected argument values:
    String name = "abc";
    String condition = true;
    PowerMockito.verifyNew(ClassUnderTest.class).withArguments(name, condition);
}

In Java 8 it is even simpler than all of the above:

when(mockObject.myMethod(anyString()))
    .thenAnswer(invocation -> 
        invocation.getArgumentAt(0, String.class));

You can control the default answers of your mock. When you're creating the mock, use:

Mockito.mock(ObjectNeedToMock.class, new Answer() {
    @Override
    public Object answer(InvocationOnMock invocation) throws Throwable {
        /* 
           Put your default answer logic here.
           It should be based on type of arguments you consume and the type of arguments you return.
           i.e.
        */
        if (String.class.equals(invocation.getMethod().getReturnType())) {
            return "This is my default answer for all methods that returns string";
        } else {
            return RETURNS_DEFAULTS.answer(invocation);
        }
    }
}));

In new Mockito versions you can use stubbing consecutive calls to throw exception on first can and returning a value on a second call.

when(mock.someMethod("some arg"))
    .thenThrow(new RuntimeException())
    .thenReturn("foo");

https://javadoc.io/doc/org.mockito/mockito-core/latest/org/mockito/Mockito.html#10

Even more meaningful :

import static org.mockito.Mockito.never;
import static org.mockito.Mockito.verify;

// ...

verify(dependency, never()).someMethod();

The documentation of this feature is there §4 "Verifying exact number of invocations / at least x / never", and the never javadoc is here.

I just found another way to solve the problem.

This is an issue for dexmaker 1.2, we should upgrade to dexmaker 1.4, dexmaker-mockito 1.4 and include dexmaker-dx-1.4.

So the dependencies are

dexmaker-dx-1.4.jar
dexmaker-1.4.jar
dexmaker-mockito-1.4.jar
mockito-core-1.10.19.jar

You need create real A class because you want to test it but you need to mock other classes used in A class. Also, you can find mockito documentation says that don't mock everything.

class ATest {
        @Mock
        private B b;
        private A a;
        @Before
        public void init() {
            MockitoAnnotations.initMocks(this);
            a = new A(b);
        }
        @Test
        public String someMethodTest() {
            String result = "result";
            Mockito.when(b.execute()).thenReturn(result);
            String response = a.someMethod();
            Mockito.verify(b,  Mockito.atLeastOnce()).execute();
            assertEquals(response, result);
        }
    }