Summary

In this chapter, we learned about writing effective and valuable test suites. Writing effective test suites is hard. The complexity and runtime of a typical test suite increases slowly, and often we don’t realize we have a serious problem until it’s too late. Paying attention to detail in keeping individual tests simple and fast pays off over time.

Test suite goal

The goal of our test suite is to allow us to use tests to improve the design and for the existing tests to empower us to make changes with less fear of introducing new bugs. If our test suite is slow, complicated, or fragile, then we make our tests unable to help us with either of these goals. In the worst case, we can find ourselves still needing to maintain a test suite but having that test suite slows down development because of how hard it is to keep the tests synchronized with the code.