This only works if your commit in a green state. Sometimes we have to change when things are still "Yellow"..
I tend to add all my tests in one go and commit the RED. "tests are written" Then as I pass each test, I commit that.
This pattern works really well for me because if I mess up, then rolling back to the last yellow is easy. I can also WIP commit if I have to fix an urgent bug, and then get back to the WIP later.
Not sure what you mean... When we ship a stack of commits, every commit has to pass everything in CI. You are not suppose to ship a commit that's not passing the ci bar. There is a escape hatch that you can bypass but it's rarely used.
You can make changes before you ship however you wanted as long as they pass ci. If you already shipped the code and want to make changes later, that means making new commit or reverting a bad commit. It's simple as that
I tend to add all my tests in one go and commit the RED. "tests are written" Then as I pass each test, I commit that.
This pattern works really well for me because if I mess up, then rolling back to the last yellow is easy. I can also WIP commit if I have to fix an urgent bug, and then get back to the WIP later.