Mockito - stub super (abstract) class method

Question

I have DAO code that looks like this:

public abstract class GenericDAO <T, I> {
    public I upsert(T entity){
        //implementation
    }
}

public class MyEntityDAO extends GenericDAO <MyEntity, Integer> {
    public List<MyEntity> searchMyEntity(SearchParameters params){
        //domain specific entity search
    }
}

public class MyEntityService{
    private MyEntityDAO myEntityDAO;

    public Integer saveMyEntity(MyEntityVO vo){
        //transform vo to entity with business logic
        return myEntityDAO.upsert(myEntityInstance);
    }        

}

I want to test the saveMyEntity() method using Mockito but mockito is showing me an error message - "the method when(t) in the type mockito is not applicable for the arguments (void)".

This is the code:

Mockito.when(myEntityDAO.upsert(Matchers.any(MyEntity.class)))
        .thenReturn(1);

This is the code that works:

Mockito.when(myEntityDAO.searchMyEntity(testSearchParams))
            .thenReturn(mockedListOfMyEntities);

It seems that because upsert() is in the superclass of MyEntityDAO and not in MyEntityDAO itself this issue is coming up. Is there any way I can achieve this? Is there any workaround or a different framework that supports this?

Answer 1

Resolved in the comments:

Seems like the issue was with the method being updated with void.. had to use Answer to modify the passed object to test the functionality.