How to use AllInvocationsFinder class of org.mockito.internal.invocation.finder package

Since Mockito 1.9.5+ and Java 8+

You can use a lambda expression, like:

when(myMock.myFunction(anyString())).thenAnswer(i -> i.getArguments()[0]);

Where i is an instance of InvocationOnMock.

For older versions

You can create an Answer in Mockito. Let's assume, we have an interface named MyInterface with a method myFunction.

public interface MyInterface {
    public String myFunction(String abc);
}

Here is the test method with a Mockito answer:

public void testMyFunction() throws Exception {
    MyInterface mock = mock(MyInterface.class);
    when(mock.myFunction(anyString())).thenAnswer(new Answer<String>() {
    @Override
    public String answer(InvocationOnMock invocation) throws Throwable {
        Object[] args = invocation.getArguments();
        return (String) args[0];
    }
    });

    assertEquals("someString",mock.myFunction("someString"));
    assertEquals("anotherString",mock.myFunction("anotherString"));
}

Mockito 1.8.1 introduced anyVararg() matcher:

when(a.b(anyInt(), anyInt(), Matchers.<String>anyVararg())).thenReturn(b);

Also see history for this: https://code.google.com/archive/p/mockito/issues/62

Edit new syntax after deprecation:

when(a.b(anyInt(), anyInt(), ArgumentMatchers.<String>any())).thenReturn(b);

Take a look at the Mockito API docs. As the linked document mentions (Point # 12) you can use any of the doThrow(),doAnswer(),doNothing(),doReturn() family of methods from Mockito framework to mock void methods.

For example,

Mockito.doThrow(new Exception()).when(instance).methodName();

or if you want to combine it with follow-up behavior,

Mockito.doThrow(new Exception()).doNothing().when(instance).methodName();

Presuming that you are looking at mocking the setter setState(String s) in the class World below is the code uses doAnswer method to mock the setState.

World mockWorld = mock(World.class); 
doAnswer(new Answer<Void>() {
    public Void answer(InvocationOnMock invocation) {
      Object[] args = invocation.getArguments();
      System.out.println("called with arguments: " + Arrays.toString(args));
      return null;
    }
}).when(mockWorld).setState(anyString());

This isn't necessarily a smell and you can partially mock Car like so:

String carId = "...";
Car car = ...;

CarServiceImpl car = mock(CarServiceImpl.class);
when(car.findById(carId)).thenReturn(car);    
when(car.deleteById(carId)).thenCallRealMethod();

But if you can allow deleteById() to execute the 'real method' then your test must already have a repository in which case letting findById() be a 'real call' is simple and improves the quality of your test coverage at ~no additional cost. The fact that you have already tested findById() doesn't mean that you shouldn't test it again, indirectly, as part of deleteById().

I would suggest that you do either or both of the following:

• Unit test Car by giving it a mocked repository and using mocked expectations and verifications to test all of its methods
• Functional/Acceptance test Car by giving it a real repository and using real invocations on the underlying store to assert actual results for each of its methods

On a separate note, I'm guessing the idea of injecting a repository into a domain object is a deliberate use of the "active record" pattern where your entities know how to CRUD themselves. This could be considered a code smell; it breaches the SRP and could be held to be a poor separation of concerns because the domain object knows about two things: its own state and how to persist itself.

I think you do need to cast it, but it shouldn't be too bad:

Foo<Bar> mockFoo = (Foo<Bar>) mock(Foo.class);
when(mockFoo.getValue()).thenReturn(new Bar());

Try:

verify(someService).process(ArgumentMatchers.<Collection<Person>>any());

Actually, IntelliJ automatically suggested this fix when I typed any()... Unfortunately you cannot use static import in this case.

This question might be old but since this was the nearest answer I found when I had this problem I though I'd describe my solution.

Using JUnit 4

Split your tests up so that there is one test method per class (this solution only changes classloaders between classes, not between methods as the parent runner gathers all the methods once per class)

Add the @RunWith(SeparateClassloaderTestRunner.class) annotation to your test classes.

Create the SeparateClassloaderTestRunner to look like this:

public class SeparateClassloaderTestRunner extends BlockJUnit4ClassRunner {

    public SeparateClassloaderTestRunner(Class<?> clazz) throws InitializationError {
        super(getFromTestClassloader(clazz));
    }

    private static Class<?> getFromTestClassloader(Class<?> clazz) throws InitializationError {
        try {
            ClassLoader testClassLoader = new TestClassLoader();
            return Class.forName(clazz.getName(), true, testClassLoader);
        } catch (ClassNotFoundException e) {
            throw new InitializationError(e);
        }
    }

    public static class TestClassLoader extends URLClassLoader {
        public TestClassLoader() {
            super(((URLClassLoader)getSystemClassLoader()).getURLs());
        }

        @Override
        public Class<?> loadClass(String name) throws ClassNotFoundException {
            if (name.startsWith("org.mypackages.")) {
                return super.findClass(name);
            }
            return super.loadClass(name);
        }
    }
}

Note I had to do this to test code running in a legacy framework which I couldn't change. Given the choice I'd reduce the use of statics and/or put test hooks in to allow the system to be reset. It may not be pretty but it allows me to test an awful lot of code that would be difficult otherwise.

Also this solution breaks anything else that relies on classloading tricks such as Mockito.

Declare the exception in the test method.

public void testAddUser() throws ServiceException {
...
}

I know this thread is old, but it's good to add that since 2014 and this pull request, you can use the @PowerMockRunnerDelegate annotation to "delegate" the run context to SpringJUnit4ClassRunner (or any other runner really).

Above code would look like :

@RunWith(PowerMockRunner.class)
@PowerMockRunnerDelegate(SpringJUnit4ClassRunner.class)
@PrepareForTest(X.class);
public class MyTest {

    // Tests goes here
    ...
}

With this annotation, you don't need the PowerMock rule anymore !