Git change history of feature-branch into a new branch?

Question

Someone else can better reword this question, but here is what I want to do:

I have been working on a long lived major-refactor branch B. I have been regularly merging master in and by now branch B is ahead of master by ~200 commits. I am ready to send a pull request now but I want to cleanup my commit history a bit. Basically I want to squash all my ~200 commits into just 3 commits:

• Commit 1 = All files that got deleted
• Commit 2 = All new added files
• Commit 3 = Everything else i.e. all moved/editted files

And, just so I don't screw it up, I would like to do this history-rewrite on a separate branch from my own branch B and send in that branch as my pull request.

What's the easiest way I can achieve this in git?

Answer 1

Let's assume you are going to merge to master:

1. Create and checkout a new branch:

   git checkout -b going-to-squash
   

2. Rebase onto master

   git rebase --squash master
   

3. Reset to the master branch

   git reset master
   

4. Now, your entire squashed branch will be in an un-committed state.

   Create your new commits now.

   I would use a gui for this step, but it's perfectly doable on the command line.

Answer 2

A git rebase --interactive (as described in the Pro Git book) wouldn't be practical, as it allows to pick or squash commits (not parts of commits)

Another way might be to generate a giant patch (like git format-patch origin/master) and then parse that file make 3 patch files:

• one with all the deletetions
• one with all the additions
• the rest

You can then create a branch from the the commit branch B originated (see "Reference Git branch start commit"), and apply those three patches.