How to use anonymousClassImplementingNotExtensible_shouldWarn method of org.mockito.errorprone.bugpatterns.MockitoNotExtensibleTest class

I think it requires more custom work.

verify(row, new LastCall()).saveToDatabase();

and then

public class LastCall implements VerificationMode {
    public void verify(VerificationData data) {
        List<Invocation> invocations = data.getAllInvocations();
        InvocationMatcher matcher = data.getWanted();
        Invocation invocation = invocations.get(invocations.size() - 1);
        if (!matcher.matches(invocation)) throw new MockitoException("...");
    }
}

Previous Answer:

You are right. verifyNoMoreInteractions is what you need.

verify(row).setSomething(value);
verify(row).setSomethingElse(anotherValue);
verify(row).editABunchMoreStuff();
verify(row).saveToDatabase();
verifyNoMoreInteractions(row);

Chris and Fildor are correct to try to mock the Logger.getLogger(). Unfortunately the way Log4J works makes that technically tricky.

Here's the code I came up with (tested) based on your sample above.

ClassUnderTest.java

import org.apache.log4j.Logger;

public class ClassUnderTest {
    private static Logger logger = Logger.getLogger(ClassUnderTest.class);

    public void run() {
        logger.info("Hello.");
    }
}

MockLog4JTest.java

import static org.mockito.Matchers.eq;
import static org.mockito.Mockito.verify;
import static org.powermock.api.mockito.PowerMockito.mock;

import org.apache.log4j.Logger;
import org.junit.BeforeClass;
import org.junit.Rule;
import org.junit.Test;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.rule.PowerMockRule;
import org.powermock.reflect.Whitebox;

@PrepareForTest(ClassUnderTest.class)
public class MockLog4JTest {
    @Rule
    public PowerMockRule rule = new PowerMockRule();

    @BeforeClass
    public static void oneTimeSetup() {
        System.setProperty("log4j.defaultInitOverride", Boolean.toString(true));
        System.setProperty("log4j.ignoreTCL", Boolean.toString(true));
    }

    @Test
    public void testLog()
    {
        ClassUnderTest classUnderTest = new ClassUnderTest();
        Logger mockLogger = mock(Logger.class);

        Whitebox.setInternalState(ClassUnderTest.class, "logger", mockLogger);

        classUnderTest.run();

        verify(mockLogger).info(eq("Hello."));
    }
}

I chose to go with using Whitebox to outright set the static field on the class under test to my mockLogger instance. After that, verification was pretty straightforward.

Two more ways to do it (see my comment on the previous answer by @Tomasz Nurkiewicz):

The first relies on the fact that the compiler simply won't let you pass in something of the wrong type:

when(a.method(any(Class.class))).thenReturn(b);

You lose the exact typing (the Class<? extends A>) but it probably works as you need it to.

The second is a lot more involved but is arguably a better solution if you really want to be sure that the argument to method() is an A or a subclass of A:

when(a.method(Matchers.argThat(new ClassOrSubclassMatcher<A>(A.class)))).thenReturn(b);

Where ClassOrSubclassMatcher is an org.hamcrest.BaseMatcher defined as:

public class ClassOrSubclassMatcher<T> extends BaseMatcher<Class<T>> {

    private final Class<T> targetClass;

    public ClassOrSubclassMatcher(Class<T> targetClass) {
        this.targetClass = targetClass;
    }

    @SuppressWarnings("unchecked")
    public boolean matches(Object obj) {
        if (obj != null) {
            if (obj instanceof Class) {
                return targetClass.isAssignableFrom((Class<T>) obj);
            }
        }
        return false;
    }

    public void describeTo(Description desc) {
        desc.appendText("Matches a class or subclass");
    }       
}

Phew! I'd go with the first option until you really need to get finer control over what method() actually returns :-)

Check the Java API for List.
The get(int index) method is declared to throw only the IndexOutOfBoundException which extends RuntimeException.
You are trying to tell Mockito to throw an exception SomeException() that is not valid to be thrown by that particular method call.

To clarify further.
The List interface does not provide for a checked Exception to be thrown from the get(int index) method and that is why Mockito is failing.
When you create the mocked List, Mockito will use the definition of List.class to creates its mock.

The behavior you are specifying with the when(list.get(0)).thenThrow(new SomeException()) doesn't match the method signature in List API, because get(int index) method does not throw SomeException() so Mockito fails.

If you really want to do this, then have Mockito throw a new RuntimeException() or even better throw a new ArrayIndexOutOfBoundsException() since the API specifies that that is the only valid Exception to be thrown.

You are reusing your context, in order to have tests independent from one another you probably need to refresh your context after each test to reset everything.

I will suppose you are using Junit 4.5+. It would be similar with other test frameworks.

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations={"mycontext.xml"})
@DirtiesContext(classMode = ClassMode.AFTER_EACH_TEST_METHOD)
public class MyTestClass {
...
    // my tests    
...
}

You can put the @DirtiesContext at the method level if the methods that need "fixing" are few, but if you are using Spring your best option is to do it after every test.

Anyway, I don't think you should be using mocks/spies in integration tests:

• In unit tests, use mocks (if you want) and inject manually. Here you want to verify the behaviour of your tested bean as a unit, so you isolate it from the rest by using mocks. This also has the advantage that JUnit isolates your tests by using a different instance of the test class for each test, so unless you use static or other test-unfriendly practices everything will just work.

• In integration tests, use real beans and let Spring inject. Here the goal is to verify that beans interact well with one another / with the environment (database, network, ...) You do not want to isolate beans here, so you should not use mocks.

See Spring documentation about testing for more detailed explanations.

As Object.getClass() is final, you cannot mock that method with Mockito. I would strongly advice you to refactor your code to inject the class in another way. If that's not possible, you could try out powermock, where you could mock any final method. Object.getClass() is a bit special, so be sure to set MockGateway.MOCK_GET_CLASS_METHOD = true in powermock.

I think this happens because mockito doesn't know the semantic meaning of isEmpty() and when it encounters a boolean method mocks it with a default value that is false. Same think happens with size() but the default value here is 0.

Basically, you need to define the expected behaviour of your mocked object. If you don't, it will return default values.

You need to inject mock inside the class you're testing. At the moment you're interacting with the real object, not with the mock one. You can fix the code in a following way:

void testAbc(){
     myClass.myObj = myInteface;
     myClass.abc();
     verify(myInterface).myMethodToBeVerified(new String("a"), new String("b"));
}

although it would be a wiser choice to extract all initialization code into @Before

@Before
void setUp(){
     myClass = new myClass();
     myClass.myObj = myInteface;
}

@Test
void testAbc(){
     myClass.abc();
     verify(myInterface).myMethodToBeVerified(new String("a"), new String("b"));
}

You are chaining method calls on your mocked instance:

@Mock
HttpServletRequest mockedRequest = mock(HttpServletRequest.class);

First of all, you do not need to do both, either use the @Mock annotation or the mock method. Like this, you first assign a Mock and then replace this instance with another mock. I recommend the annotation as it adds some context to the mock such as the field's name. This might already cause your NullPointerException as you however never activate the annotations by calling:

MockitoAnnotations.initMocks(this);

as you do not consequently mock all instances with both measures so far. However, even doing so will further result in your exception, so let's move ahead.

Within friendWebService.createFriendRequest(mockedRequest) you call:

User user = (User) request.getSession().getAttribute("user");
User otherUser = (User) request.getSession().getAttribute("profileuser");

where you call a method on two mocks for which you did not specify any behavior. These mocks do by default return null. You need to specify behavior for this such as:

when(request.getSession()).thenReturn(myMockedSession);

before performing this chained call. Based on this, you can then specify how to react to calls on this mocked instance such as returning your user mocks.