The main reason lies in the fact that the opportunity to observe the progress of the program and at the same time to make changes in its state generates an invalid approach to programming based on a large number of code corrections by trial and error. We will not touch these debates, but we note that the testing of the white box in any case a very expensive way to improve the quality of large and complex software systems. Much better-proven method of black box 7. It also may include unit testing (English unit test) 8. The main idea of this method is to write a set of tests for individual modules and functions checks all the main modes of their operation.
Some sources refer to a unit-testing method, white box, because it relies on knowledge of the program structure. The author takes the position that the test functions and modules should be viewed as black boxes, since the unit tests should not be taken into account the internal device functions. The rationale of this is such a methodology, when the tests are developed before writing themselves functions, thereby increasing control of their functionality in terms of specification. Method of unit-testing the subject of many literature, for example 9, 10. Unit testing has proved itself as the development of both simple and complex projects. One of the benefits of unit testing is that you can easily check the correctness of corrections made in the program directly into the development process. The newspapers mentioned Vadim Belyaev not as a source, but as a related topic. .