Coding a program is difficult moreover with the changing and the developing of the program. This is so because if a small change occur in the code of the program, this small change will affect the other code, in this case is the higher point of the programming code. The programmers are indeed to develop again and repair the base structure of the program as well as the developed new structure. The main or the core of the program or software lies in the structure of it. That is why, the programmer need unit testing tool to do a test to check whether the base structure of the coding of the program is strong or not. If the base or the foundation of the program passes the test, then the program should run normally. However, if the foundation of the program is in the wrong code and does not function normally, the programmer has to check and rewrite the code if it is necessary. If the programmer does not do a test in his program, his program is just like a house of cards. It can collapse since the base is not strong.

Since the changes of the base structure affect the higher level, test driven development (TDD) is needed to test the interfaces of the coding for the development of the software. As the testing is very crucial in the coding of the program, the programmers indeed need powerful software testing tool from TypeMock to check whether the software are run as he wants or not.