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A small TIL for Git lovers: `git merge-base HEAD main` gives you the nearest common commit between the current branch and main. That's the commit where those two parted ways.

Stefan Luptak

@stefanluptak.com

10 Mar

I use that when doing Credo in CI: mix credo diff --from-git-merge-base <your-base-branch> --strict

Elixir ▷ Max

@mxgrn.com

Interesting! So, if this runs checks on a feature branch, then <your-base-branch> would most often be 'main', right?

10/3/26, 12:15 pm0 reposts0 likes

Stefan Luptak

@stefanluptak.com

10 Mar

Exactly. It's useful to run checks only on the changes you're introducing in the feature branch. Useful in big codebases. But we introduced that a long time ago. Nowadays with the help of AI, it's not that difficult to do a refactor throughout the codebase to enforce a newly introduced Credo rule.