How to mock protected method in Java

[intelrate]

Here is a question.

I wanted my JUnit tests to be more modular and found how to mock protected methods for that purpose. Briefly speaking, we cannot mock and control calls of protected method with JDK dynamic proxy because protected methods are not in any interface but we can create MockInterface with mock method under control and call it from overridden protected method to achieve our goal.

The problem I’m trying to resolve now is that my mock method should have the same number of parameters as protected method I want to mock. It forces me to create several mock methods with different number of parameters which is not elegant. Does anyone know better solution in JMock or other Java framework? Any help would be very appreciated.

[JosAH]

Extend your class and override your protected method by a public one; test your extended class and your overriding public method.

kind regards,

Jos

[intelrate]

Thank you JosAH

That's what I'm doing right now. The problem is that if my protected method has 2 arguments then my mock method should be like

Object mockMethod(Object parameter1, Object parameter2);

If I need to mock another protected method with 3 parameters then I have to create

Object mockMethod(Object parameter1, Object parameter2, Object parameter3);

It works for me but probably there is another approach to mock protected methods which I don't know about.

Cheers!

[JosAH]

@intelrate
Not that I know of but you shouldn't mock protected methods in the first place; you should mock the API of the class (the methods published in its interface).

kind regards,

Jos

ps. Was this just a 'pro forma' question? You already turned it into a blog entry ...

[intelrate]

@JosAH
Actually I'm not totally happy with the solution I have but for now it should be fine.

Thanks.