This Git command script allows you to edit/modify/merge previous Git commits easily. It essentially is a more convenient version of using git rebase --interactive for that use case.
git-edit [-m | --message | -d | --drop | -s | --squash ] <commit> [<target>]
-m, --message Alter <commit> message after editing
-d, --drop Just delete (drop) <commit>
-s, --squash Merge (fixup/squash) <commit> into the previous one
-s <target>, --squash <target> Merge (fixup/squash) <commit> into <target>
This script will stash any local changes, then reset your local copy to the state of the commit you want to edit, then pause to let you make changes. After resuming, all changes will be added (amended) to the commit, and the rebase will continue.
The script also pauses in case any merge conflicts arise, so you can manually resolve them before continuing with the merge/rebase. After completion, your previous local changes will be unstashed/reapplied.
If you want to alter the commit message after editing as well, add the -m/--message switch. You can also delete (drop) a commit instead of editing by using -d/--drop, or merge (fixup/squash) it into another one (defaulting to the previous commit) using -s/--squash. Whenever two commit hashes are supplied, -s/--squash is assumed automatically and the older commit becomes the <target>.
You can use it simply as git edit by adding its parent folder to your PATH, e.g. by adding this line to ~./zshrc: export PATH=$PATH:/your/path/to/git-custom-commands.
Note that this will change the SHA1 of the commit as well as of all later commmits – it rewrites the history from that point forward. This is unproblematic as long as you either didn't push these commits yet, or are a single developer. If not, it can cause other maintainers, branches, or forks quite a hassle. So please know what you're doing when using git push --force!