Git Hygiene: How to Automatically Delete Stale Local Branches

Feature branches in Git can quickly pile up. I like to keep my branches clean because when using auto completion I don't want to go through a list of branches that have already been merged or discarded. And I just like to keep things clean and tidy in general.

Created with Gpt4o

Primer on Git branches

Let's say you have a feature branch feat/notifications. You push that branch to the remote repository to create a PR. The remote is usually named origin so you will have another branch, in your local repository, called origin/feat/notifications that tracks the remote branch.

Try git branch -vv to see all the branches and their tracking branches.

$ git branch -vv
* feat/notifications a84be78 [origin/feat/notifications] feat: add notifications
  main               2831500 [origin/main] chore: remove deadcode

Delete remote branches locally

Now, assume the PR got merged and the branch feat/notifications was deleted from the remote repository.

Running git fetch -p (short for git fetch --prune) will delete the origin/feat/notifications branch from your local repository but not the feat/notifications branch.

If you list the remote branches again, you'll see that the branch is marked as gone.

$ git branch -vv
* feat/notifications a84be78 [origin/feat/notifications: gone] feat: add notifications
  main               2831500 [origin/main] chore: remove deadcode

So we have just deleted the remote tracking branch. But how do we delete the local branch?

When you run git fetch -p, it lists out all the remote tracking branches it just deleted. Then, for each of those branches, you need to manually run git branch -D <branch-name> to delete the branch from your local repository.

This is how I've been doing it so far but there's a better way to do it.

List out all the stale branches

git branch -vv | rg '\\[.*gone.*\\]' | sed 's/^..//' | cut -d' ' -f1

This uses a few unix commands to extract the name of the branches that have been deleted from the remote repository. Finally, we use xargs to delete the branches from the local repository.

git branch -vv | rg '\\[.*gone.*\\]' | sed 's/^..//' | cut -d' ' -f1 | xargs -r git branch -D

To break it down

• git branch -vv - Lists all branches with their tracking information
• rg '\\[.*gone.*\\]' - Filters branches that have been marked as "gone" (deleted from remote)
• sed 's/^..//' - Removes the first two characters from each line (which are either * for the current branch or for other branches)
• cut -d' ' -f1 - Splits the line by spaces and extracts the first field, which is the branch name
• xargs -r git branch -D - Passes each branch name to the git branch -D command to delete it locally

Setup an alias in Git config

I have this as an alias in my git config in ~/.config/git/config

[alias]
    clean-gone = "!git branch -vv | rg '\\[.*gone.*\\]' | sed 's/^..//' | cut -d' ' -f1 | xargs -r git branch -D"

Now, I can simply run git pull && git fetch -p && git clean-gone to clean up those stale branches.

$ git pull && git fetch -p && git clean-gone
Deleted branch feat/notifications (was a84be78).