Hey,
Once it has matched a case, it calls a method in another class...never returning anything, or changing any variable to test.
When you say you call a method in another class, how are these classes created?
Do you initialise the class using "new" and then call the method?
Or
Are the classes that you call the methods on set using setters?
If the latter and if you are using interfaces then you can use something like EasyMock to check that the correct class/method is being used for the String input that you have entered.
Sean