How to mock persisting and Entity with Mockito and jUnit

Question

I\'m trying to find a way to test my entity using Mockito;

This is the simple test method:

@Mock
private EntityManager em;

@Test
public void persistArti         


        

Answer 1

public class AssignIdToArticleAnswer implements Answer {

    private final Long id;

    public AssignIdToArticleAnswer(Long id) {
        this.id = id;
    }

    @Override
    public Void answer(InvocationOnMock invocation) throws Throwable {
        Article article = (Article) invocation.getArguments()[0];
        article.setId(id);
        return null;
    }
}

And then

doAnswer(new AssignIdToArticleAnswer(1L)).when(em).persist(any(Article.class));