Chapter 12. Test Cleanly

Working tests are the most precious asset in any software development project. They not only show that your system is still useful in some way, but they also document what the system does—and you can check that with the press of a button if you have automated your tests.

Since working tests are so valuable to your development project, you should keep them working under all circumstances—or make an informed decision to get rid of them. With today’s version control systems it’s not a shame to throw away things that you no longer need. In fact, it gives you some relief. Teams not only report that fewer tests provide them with more flexibility (see [Adz11]), but also relieves some of the burden to our brains [Hun08].

You may argue that a good organization of test cases helps you do that, too. But up to which point do you want to keep all of your tests? A few years back I was part of a project for a customer in Brazil where the testers automated all tests that came to mind. Brazil has a tax system that allows each of the twenty-seven states to apply a different tax system. In our system our programmers had to configure one subset for each tax system.