How to mock method with generic argument type

Question

I have this method

public <T, R> R deepCopy(T source, R destination) {
   beanMapper.map(source, destination);
   return destination;
}

and want to mock with different method params like

mock.deepCopy(classA(), classB()).thenReturn(classB());
mock.deepCopy(classB(), classC()).thenReturn(classC());

but getting class cast exception.

Have you seen this question? https://stackoverflow.com/questions/1652692/using-mockito-to-mock-classes-with-generic-parameters — Lorelorelore, Aug 06 '18 at 10:48

score 1 · Accepted Answer · answered Aug 06 '18 at 11:13

How about this

doAnswer(invocation -> {
       Object arg1 = invocation.getArguments()[0];
       Object arg2 = invocation.getArguments()[1];

       if(arg1 instanceof Integer && arg2 instanceof String)
           return "something";
        if(arg1 instanceof String && arg2 instanceof Boolean)
            return false;

        return false;
}).when(yourmock).deepCopy(any(), any());

Now if you pass call the method with arguments (1, "abcd"), the mock willreturn "something". And if you pass ("abcd", true) then it returns false

How to mock method with generic argument type

1 Answers1