Delete Tests

Summary

30 Jun 2025You should delete testsWe’ve had decades of thought leadership around testing, especially coming from wholistic development philosophies like Agile, TDD, and BDD. After all that time and several supposedly superseding movements, the developers I talk to seem to have developed a folk wisdom around tests.That consensus seems to boil down to simple but mostly helpful axioms, like “include tests for your changes” and “write a new test when you fix a bug to prevent regressions”. Unfortunately, one of those consensus beliefs seems to be “it is blasphemy to delete a test”, and that belief is not just wrong but actively harmful.Let’s talk about why you should delete tests.To know why we should delete tests, let’s start with why we write tests in the first place. Why do we write tests? At the surface level, it’s to see if our program works the way we expect. But that doesn’t explain why we would write automated tests rather than simply run our program and observe if it works.If you’ve ever tried to work on a project with no tests, I’m sure you’ve experienced the sinking sensation of backing yourself into a corner over time. The longer the project runs, the worse it gets, and eventually every possible change includes stressfully wondering if you broke something, wondering what you missed, and frantically deploying fix after revert after fix after revert as fast as possible because each frantic fix broke something else.That nightmare is why automated tests exist: we need to be able to write software with confidence that we aren’t accidentally breaking everything we made before. The bigger a project gets, the more possible failures there are, and the more tests you need to have confidence it all works at the same time.Confidence is the point of writing tests.You run the tests so you can be confident when you open a pull request. CI runs the tests so you can be confident when you merge. CD runs the tests so you can be confident when you deploy. Tests exist to increase...