git split commit

TL;DR: git rebase -i, edit, git reset HEAD~ and create new commits

When you squashed too much and want to split a git commit into several ones. More wordy explanation on StackOverflow, shorter version here:

1. Use git rebase -i ...

2. Mark desired commit to be edited

3. Rebase will now pause after this commit

4. Run git reset HEAD~ to cancel the commit

5. Use your favourite tool(s) to create new commits

6. When finished, run git rebase --continue

Note that you should commit all changes!

Also note that this approach deletes old commit and creates new ones, so date and author will be reset.

Alternatively, to move a change from a commit into a new commit (for example, adding a sub-feature to a new feature), you can:

1. Use git rebase -i ...

2. Mark desired commit to be edited

3. Rebase will now pause after this commit

4. Edit file(s) to reverse the change (in our example, remove the sub-feature)

5. Create a (temporary) commit, call it "reverse sub-feature", for example

6. Immediately after that, run git revert HEAD

7. It will create a new commit, and call it "Revert: reverse sub-feature" - cancel the double-negative and reword it to "add sub-feature"

8. Run git rebase --continue to finish the rebase

9. Use git rebase -i ... again, to fixup your temporary commit ("reverse sub-feature" in our example) into the main commit

And then you'll have your main commit without the sub-feature, followed by a commit adding the sub-feature - exactly what you wanted!

Also, as a bonus - one-liner to create individual commits for each modified file:

git status --porcelain | sed 's/^...//' | xargs -I% sh -c 'git add %; git commit -m "cleanup %" '