Git One Liners: Bulk-Amending a Branch

I made a mistake with my git config recently (I’ve updated Separating work and personal config to avoid that mistake 😬), and ended up creating all the commits in a branch with the wrong email address. The also should have been signed and they weren’t.

Here’s how to fix that in one go:

git rebase \
--exec 'git commit --amend --no-edit -n --gpg-sign --author="Evan Moses <the.correct@email.address>"' \
$(git merge-base origin/main HEAD)

Breaking it down

git rebase # Rebase some commits

--exec # And execute the following command for each commit

git commit --amend --no-edit -n # Amend the commit without changing the commit message,
                                # contents, or running any git hooks

--gpg-sign --author="..."` # This is the bit I actually wanted to do differently

$(git merge-base origin/main HEAD) # This is a useful command to find the "branch point"
                                   # where your current branch diverges from main.

So: this will iterate over all the commits on my current branch and amend them. Done.