Testing private method of an abstract class using Reflection

Question

How can I test a private method of an abstract class using reflection (using C#)? I am specifically interested in adapting the code found in this thread.

I am aware of the discussion around the principle of testing private codes in the first place (one should not in general !!). I have already decided to do that for my situation because of various reasons, so let's not repeat those discussions. Other SO threads (like Q# 1583363 and 1506427) discuss them in detail. Thanks.

Answer 1

By definition, and abstract class cannot be instantiated, so you can't test it directly. You could use one of the mocking frameworks (like TypeMock. Otherwise, you'll need to create a concrete class that inherits from the abstract class, and use that for testing.

Answer 2

If your using VS2008 then it's as easy as right click your private method and selecting create unit test. VS will create a YourAbstractClass_Accessor class that will allow you to see and run that private method.

Note: No additional mocking framework necessary.

Answer 3

You can do this, this is not reflection though, might be help for somebody.

var concreteClass = new concreteClass();
var po = new PrivateObject(concreteClass, new PrivateType(typeof(AbstractClass)));
Object[] args = new object[] {...};
po.Invoke("PrivateMethod", args);