Moving Changes From One Git Branch to Another

When working with branches in Git, you will sometimes make some changes to your code only to realize that you are not working in the branch that you thought you were. Thankfully, this is easy to remedy, as long as you haven't committed the changes. This tutorial introduces the stash command of git, which allows you to easily move the changes to the correct branch.

The Situation

We address the following situation:

• You have multiple branches in your local repository. For this tutorial, we'll work with master and feature branches.
• You are working in a given branch, and have saved some changes.
• Your changes have not been stages or committed.
• You want to move your changes to another branch.

If this situation describes you, you're in luck! Let's fix it.

Using Git Stash

Suppose you have a branch called feature that you want to work in. You've made some changes, and saved them, only to realize that you're in (Gasp!) the master branch.

$ git status
On branch master
Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)
  (use "git checkout -- <file>..." to discard changes in working directory)

    modified:   main.py

no changes added to commit (use "git add" and/or "git commit -a")

At this point, you might try to git checkout feature, and you might encounter this error:

$ git checkout feature
error: Your local changes to the following files would be overwritten by checkout:
    main.py
Please commit your changes or stash them before you switch branches.
Aborting

This error results from the situation in which your feature branch has commits that your master branch doesn't, so Git can't move the un-staged changes you made in master cleanly over to feature.

Take a deep breath. This is an easy one to remedy.

Use git stash to put these changes off to the side for a moment.

$ git stash
Saved working directory and index state WIP on master: 1da4892 Introduce render_template
HEAD is now at 1da4892 Introduce render_template

Your message will differ, based on the most recent commit that you made in the given branch.

Note that your master branch is now "clean".

$ git status
On branch master
nothing to commit, working tree clean

Now, safely switch to the feature branch.

$ git checkout feature
Switched to branch 'feature'

And then pick up the changes that you stashed, and put them in the feature branch using git stash pop.

$ git stash pop
Auto-merging main.py
On branch feature
Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)
  (use "git checkout -- <file>..." to discard changes in working directory)

    modified:   main.py

no changes added to commit (use "git add" and/or "git commit -a")
Dropped refs/stash@{0} (cb556d3734ed8675b6b81f5d4e37d003bd1bc6b9)

That's it! Carry on coding...

References

• Git Stash Tutorial