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How to quickly / safely keep my project up to date with branches (and avoid avoidable problems)

August 26, 2018

I got into a bit of a mess earlier today when I accidentally checked out an old state of my current branch without creating a new branch for it. This resulted in a detached HEAD state.

detached head

Among other problems, this meant that when I looked at my history, it was just the initial commit (which was the hash a5c779c that I’d checked out).

git head

I was able to recover the work because the past changes had been saved in my .git directory, but in order to recover them, I had to checkout that directory by name since it wasn’t part of the current stream.

This was a scary moment, so I went about looking for a better way of doing things.

After reading several answers and articles on stackoverflow, medium, and other sites, the general approach I’ve seen boils down to a few steps that leverages branches — and thereby avoids the detached HEAD state.

Here are the steps:

  1. Create a new branch for the new feature that I want to work on
$ git checkout <new branch name>
  1. Make your changes to the branch

    Follow the standard workflow of tracking status $ git status, adding files for tracking $ git add [file name], committing those changes with a message $ git commit -m "[message for commit]".

  2. When you’re ready to merge the branch into your master, check out the master, $ git checkout master to return to the master branch
  3. [When working on a team where the master may have changed] Make sure that the master is up to date:
$ git pull origin master
  1. Merge the new branch into the master with $ git merge <new branch name>
  2. Now that the files are merged, you can delete old branches. One quick way to see what’s already been merged (and therefore ready to be deleted is $ git branch --merged. confirm merged and unmerged branches
  3. Once a branch has been merged, it can be safe to delete it. To do so, use $ git branch -d [branch name] (the -D flag is a force delete). successful delete
  4. Now, make sure that nothing hasn’t yet been merged which should be using $ git branch --no-merge

Though these steps are a faithful reproduction of my process, the way I really got more comfortable was by creating a test repo and testing all of this out. Making frequent use of $ git log, $ git branch, and $ git status.

Additional Reading

  1. Git - Basic Branching and Merging - Unsurprisingly, the best resource I’ve found. Makes me wonder why I felt the need to re-write it, except that I I read this first and didn’t understand it until I read several other articles and tested it myself. Only now on revisiting it, does it make a ton more sense.
  2. Git housekeeping tutorial: clean-up outdated branches in local and remote repositories - Found this useful for an introduction to cleaning up old branches.
  3. Best (and safest) way to merge a git branch into master - Stack Overflow - This Q&A addresses the additional complexity of what happens when the master changes (similar to the hotfix example in the Git - Basic Branching and Merging article).

Stephen Weiss

Thanks for reading! My name's Stephen Weiss. I live in Chicago with my wife, Kate, and dog, Finn.
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