How can I mock bean returning its own parameter?

Question

I have a repository class something like ...

public class StuffRepository {
    public Stuff save(Stuff v);
}

I want to make a mock with @MockBean returning first parameter v. How can I do that?

@MockBean
private StuffRepository stuffRepository;

public void test() {
    given(stuffRepository.save(??)).willReturn(??);
}

Answer 1

Mock up Stuff and have that be the return value.

@MockBean
private StuffRepository stuffRepository;
@Mock
private Stuff v;

public void test() {
    given(stuffRepository.save(v)).willReturn(v);
}

Answer 2

You use the Answer mocking version.

given(stuffRepository.save(any())).will(i -> {
    return i.getArgument(0);
});