Create Git branch with current changes

Question

I started working on my master branch thinking that my task would be easy. After a while I realized it would take more work and I want to do all this work in a new branch.

How can I create a new branch and take all these changes with me without dirtying master?

Answer 1

If you hadn't made any commit yet, only (1: branch) and (3: checkout) would be enough.
Or, in one command: git checkout -b newBranch

With Git 2.23+ (Q3 2019), the new command git switch would create the branch in one line (with the same kind of reset --hard, so beware of its effect):

git switch -f -c topic/wip HEAD~3

As mentioned in the git reset man page:

$ git branch topic/wip     # (1)
$ git reset --hard HEAD~3  # (2)  NOTE: use $git reset --soft HEAD~3 (explanation below)
$ git checkout topic/wip   # (3)

1. You have made some commits, but realize they were premature to be in the "master" branch. You want to continue polishing them in a topic branch, so create "topic/wip" branch off of the current HEAD.
2. Rewind the master branch to get rid of those three commits.
3. Switch to "topic/wip" branch and keep working.

Again: new way (since 2019 and Git2.23) to do all that in one command:

git switch -f -c topic/wip HEAD~3

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Note: due to the "destructive" effect of a git reset --hard command (it does resets the index and working tree. Any changes to tracked files in the working tree since <commit> are discarded), I would rather go with:

$ git reset --soft HEAD~3  # (2)

This would make sure I'm not losing any private file (not added to the index).
The --soft option won't touch the index file nor the working tree at all (but resets the head to <commit>, just like all modes do).

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