Use fzf to extract files into clean commits from work-in-progress branches

git extract <source_branch> <target_branch> [<main_branch>]

$ git extract origin/wip-feature-dirty feature-clean origin/main

Just drop the git-extract script into your $PATH and make sure it's executable.

I often work on long-living dirty feature branches, saving garbage "wip" checkpoints, before I fully understand what am I even doing.

When the feature is finished and tested, I end up with the garbage log that's mostly meaningless, but not quite. I find it hard to separate sensible commit messages from those that served only as a snapshot of some intermittent state.

Usually the main units I can reason about are files/directories/namespaces etc. So before submitting a proper PR, I need to, not only rebase against the main branch, but also tidy up the log.

This script aims to help with that, provided I know which paths should eventually end up in the clean, public branch annotated with descriptive commits others could then review.

The script will open a new fzf multi picker window with all the files changed between <source_branch> and <main_branch>. After selecting one or more files, it will switch to <target_branch>, creating it, if necessary, and then restore selected file(s) into it.

The commit message will be pre-populated with a comment containing all the commit messages associated with selected file(s), as seen in <source_branch>.

In case multiple authors were involved, the Co-authored-by header(s) will be automatically added.