You don’t necessarily need automated tests, but you absolutely do need to test your tests. With any new test, I always verify that 1) it passes with the fix 2)

You don’t necessarily need automated tests, but you absolutely do need to test your tests. With any new test, I always verify that 1) it passes with the fix 2) it fails without the fix. Many programmers skip step 2 and it’s a good way to end up with tests that don’t test what you think they do.