Mocking deep objects in Mockito

Question

I want to achieve the following :

Class A{
List<Class B> list;
}

Class B{
}

@Mock
A a;
when(a.list.isEmpty()).then(true); // this throws an error

By using this :

@Mock(answer = Answers.RETURNS_DEEP_STUBS)
A a;

I have to use a getter :

when(a.getList().isEmpty()).then(true);

But I don't want to change my code to use getters everywhere..

Answer 1

You cannot mock direct access to a member variable. So you have a few options:

1. Use a getter.

2. Set the member variable to be a mock instance ( a.list = mock(...) or equivalent).

3. In the case of a trivial class like a list, there's marginal value to using a mock as you can more or less directly set up the behaviour you want. So in this case, a.list = new ArrayList<>(); would suffice.