I have a class with one public method Send() and a few private methods. It calls a couple of webservices and processes the reponse. The processing is done in private methods.
I want to unit test the code. My understanding is that unit tests should test my code in isolation (ie mock up supplier responses).
I also believe that private methods should not need to be unit tested But if I just test the Send() method my code isnt being tested in isolation and is dependent on the supplier resonse.
Should I then make my private methods public so I can test them with mock responses? It seems bad practice since I only the class should need to call them.
Apologies if its a basic question, im fairly new to unit testing.
Im using c# and VS2010
Best Answer
You should separate the code dealing with the web services (i.e. sending and receiving data) from the code processing the results. Move the latter code into a distinct class, making the necessary methods public. Then you can easily unit test the processing logic, in isolation from the external dependencies.
By this, you also make your code conform to the Single Responsibility Principle. As a general rule of thumb, feeling the need to test private methods is often an indication that the class has too many responsibilities, thus should be refactored into multiple classes.