The red-green testing technique has payed dividends for me over the years. Now I'm having Claude do it for me.
## When testing a new feature or bug fix
Work test-first. When fixing a bug, write or update a test that reproduces the
broken behavior and watch it fail (red) before you touch the implementation.
Apply the fix, then re-run and watch it turn green. Without seeing red first,
you can't tell a real guard from a test that would pass either way.