Chapter 15 - Loose Ends and Opportunities

Abstract

This chapter reflects on the various issues neglected in testing and the opportunities they present. The programming level is ideal for the use of automated unit tests, not only to reduce the number of bugs, but also to facilitate the developer's work. Test cases do not slow down the programming process; they accelerate it, because they catch errors early and they facilitate refactoring of an existing program, or even make it possible in the first place. The test-first approach is a continuation of the test automation idea. This approach requires the creation of test cases before creating the actual application code. This means that tests assume a new, additional task: they considerably influence the design of an application and are thus the control instrument of an evolutionary design. As plausible as this step-by-step approach may sound, it has one big drawback: writing unit tests around legacy code is as easy as creating tests before the implementation only in rare cases. It is impossible to formulate a universal recipe for how to solve the problem in a specific case. Most of these cases require a sound mixture of caution and instinct to secure the most problematic parts of legacy code by test cases and to make them accessible to refactoring or to a complete replacement.