Why I Create Atomic Commits In Git

I wrote about how to craft changes into small atomic commits using Git. It looked like there was some confusion so I elaborated with my post on why I create atomic commits in Git.

I don't know what the official definition is but to me an atomic commit is a commit that is focused on one context and one context only. By context I mean a single topic: a feature, bug fix, refactor, upgrade, task...

In a monolithic commit everything is committed in one go. A tightly coupled, tangled, or a spaghetti commit. The larger the commit, the more brittle and error prone it becomes because it becomes harder to understand, read, review and revert.

Why atomic?

They are easier to:

• track - I know where they are in the history. git log --oneline shows me all commits. git log --grep <pattern> lets me find a commit based on a partial message. git log <commit> will jump to that commit and show previous commits.

• understand - I document each change with a commit message and elaborate with an explanation if I need to.

• read - it's a change focused on a single context which makes it smaller, simpler and easier to read the patch git show <commit> or git log <commit> -p

• review - as it is a small, focused, documented change, a reviewer should easily be able to follow the code changes and keep their sanity.

• revert - reverting git revert <commit> an atomic commit will not revert unrelated changes like a monolithic commit would.

What do I do?

• Work on one thing
• Keep my changes as small as possible
• Commit often
• Be vigilant that tests pass
• Use an interactive rebase rebase -i or interactive mode git add -i when I mess up the order of my commits or litter my working directory with different features

What about the real world?

I don't always get it right, sometimes things get messy and I end up with more than I can chew because I didn't follow my guidelines. I aim to stick to them as best as I possibly can.

What is my end goal?

I want to pragmatically craft relevant changes for a better history, cognitive load and an easier means to rollback changes.