I have the C++ code of a exe which contains a UI and some process. My goal is to remove the UI so that I only have the process and to convert the exe into a dll. In order to do that, I am thinking of generating unit test before touching any code and then to do my modification and make sure the tests are not failing. The problem is that I am not sure if this is the best approach and if it is, is there a way to automatically generate unit test. BTW, I am using VS 2012. Do you have any guidance for me?