Git commit style: All changed files at once or one at a time?

Question

I am saving my work at night with a single commit for many files. I wonder if it would be better to commit for each file but this seems like a lot more work.

I have

Answer 1

"Easy to understand" means also:

• commits representing not just "checkpoint" (like they would if you committed after each file modification), but a coherent state of the code
• easy to git bisect (ie each commit should represent a change in a task, which compiles and add an evolution or a new feature, and not a "checkpoint commit", which would make the git bisect fails way too soon)

See "understanding the Git workflow" for more: you need to differentiate:

• private branches (that you never push), where you can commit basically at any time, and
• public branches (that you will push on GitHub), which needs to be clean-up and have meaningful commits.

So pay attention to the "fast-forward" merge that Git uses by default: don't forget to clean-up the history of branches you are about to merge that way into public branches.

Answer 2

When to commit and what to commit is an art, and there are no black-and-white rules. That being said, there are habits that are easier to understand than others.

In general, I think you should optimize your commits for understandability - if you go back and read the diff for the commit, can you figure out what you accomplished in the changes?

If you want to be more specific, here's a long list of what I think are do's and don'ts:

• Don't commit after every single little change - every line changed, every file changed, etc.
• Don't work for an entire day and make one gigantic commit at the end of the day.
• Do separate out commits for different features - e.g. developing feature foo vs. fixing bug #2.
• Do a separate commit for moving/renaming files, because it's easier for Git to track this way.
• Do think about optimizing for revertability: If you dislike a change that you made, is it easy to undo it even after new changes have been piled on top?