Unit tests represent just one of the types of tests you could and should write. In this chapter, we’ll discuss how unit testing fits into an organizational testing strategy. As soon as we start to look at other types of tests, we start asking some really important questions:
- At what level do we want to test various features? (UI, backend, API, unit, etc.)
- How do we decide at which level to test a feature? Do we test it multiple times on many levels?
- Should we have more functional end-to-end tests or more unit tests?
- How can we optimize the speed of tests without sacrificing trust in them?
- Who should write each type of test?
Different industries might have different test types and levels. Figure 10.1, which we first discussed in chapter 7, is a rather generic set of test types that I feel fits 90% of the organizations I consult with, if not more. The higher the level of the tests, the more real dependencies they use, which gives us confidence in the overall system’s correctness. The downside is that such tests are slower and flakier.