The blog post How Do I Know My Tests Add Value? by AutomationPanda discusses the value of proper testing. The author brings up the common issues that sprout from use a bug-fixed count as a metric for successful testing, and highlights why testing is important and can help improve development.
Testing is important because it validates that your program is working as it is expected to. Well-written tests with the proper amount of coverage give you information about your program and whether any changes need to be made. A passing test indicates correctness and that your program is working as expected. A failing test points out a bug that needs to be fixed and helps highlight weak parts of your code.
The absence of testing might not necessarily lead to bugs, but we all know as programmers that even when it seems your code is running exactly as you intended it to, logic errors can happen and sometimes things weren’t written with every situation in mind. When testing is in being implemented, developers are accountable for the code they write, and must think carefully about the issues that may arise.
Tracking bugs isn’t necessarily effective because it encourages testers to find issues even when there may not be any. All tests passing is still good news and a sign of progress, even if it just means you are doing everything right. Enforcing bug quotas and forcing testers to find issues means they will expend effort looking for things that aren’t there and nitpicking small issues rather than writing more tests or making sure they have good coverage, which are far more effective and finding issues in your code.
At the end of his post, the author suggests some different metrics to use: time-to-bug discovery, coverage, and test failure proportions. All of these serve as much more accurate and effective measures of determining whether your testing has value. Whatever metric you use, it is important to think about why you are testing and whether you are doing it in a way that tells you something about your program.