The author imagines that the value of tests would be to detect errors the developer does not know about as they initially write the code. They are understandabl

The author imagines that the value of tests would be to detect errors the developer does not know about as they initially write the code. They are understandably skeptical that tests can provide that kind of value. In my experience, the "error detecting" value that a test sometimes gives you only occurs when you revisit code. Preventing regressions is very nice, but this is still not the main value of tests. The real benefit of writing tests comes when you write them before you write any production code. That way the tests give you feedback about your software design. Code that is difficult to test is also difficult to use correctly. They also complain about the friction you feel when you want to change behavior, but tests require the existing behavior. In this case the test should be changed or deleted. People are often too hesitant to delete tests.