Hacker News new | ask | show | jobs
by majikandy 2171 days ago
Not if you rewrite/change the tests first, since you know the code currently works and you are safe to refactor the tests. Equally you are safe to change the tests to define the new behaviour, and then follow on with changing the code to make it green.
2 comments
david-s 2171 days ago
The point was to change the code structure without changing the tests (possibly to enable a new feature or other change). The challenge being when the tests are at the wrong "level", probably by team policy IME. If you change the tests, how can you be sure the behavior really matches what it was before?
link
ric2b 2170 days ago
Agreed. I see tests as the double entry accounting of programming, they let you make changes with a lot more confidence that you're only changing what you want and not some unexpected thing.

They're not for catching unknown bugs, they're for safer updates.

link