How to Flatten git Commits

By  on  

One of my least favorite tasks as a software engineer is resolving merge conflicts. A simple rebase is a frequent occurrence but the rare massive conflict is inevitable when many engineers work in a single codebase. One thing that helps me deal with large rebases with many merge conflicts is flattening a branch's commits before fixing merge conflicts. Let's have a look at how to flatten those commits before resolving those conflicts!

My typical command for rebasing off of the main branch is:

# While on the feature branch...
git rebase -i master

To flatten commits before the rebase, which can make resolving merge conflicts easier, you can slightly modify the original command:

# While on the feature branch...
# git rebase -i HEAD~[NUMBER_OF_COMMITS]
git rebase -i HEAD~10

The example above would flatten the last 10 commits on the branch. With just one single commit, you avoid the stop-start nature of fixing merge conflicts with multiple commits!

Recent Features

  • By
    Facebook Open Graph META Tags

    It's no secret that Facebook has become a major traffic driver for all types of websites.  Nowadays even large corporations steer consumers toward their Facebook pages instead of the corporate websites directly.  And of course there are Facebook "Like" and "Recommend" widgets on every website.  One...

  • By
    Create a CSS Cube

    CSS cubes really showcase what CSS has become over the years, evolving from simple color and dimension directives to a language capable of creating deep, creative visuals.  Add animation and you've got something really neat.  Unfortunately each CSS cube tutorial I've read is a bit...

Incredible Demos

  • By
    Introducing MooTools Dotter

    It's best practice to provide an indicator of some sort when performing an AJAX request or processing that takes place in the background. Since the dawn of AJAX, we've been using colorful spinners and imagery as indicators. While I enjoy those images, I am...

  • By
    MooTools History Plugin

    One of the reasons I love AJAX technology so much is because it allows us to avoid unnecessary page loads.  Why download the header, footer, and other static data multiple times if that specific data never changes?  It's a waste of time, processing, and bandwidth.  Unfortunately...

Discussion

  1. Jeff Berman

    Some of the code in my previous comment got stripped out. The command I use to merge a branch into master while flattening it to a single commit is:

    # While on the master branch...
    git merge --squash branch_name
    

    Seems there are always multiple ways to do things, especially in Git.

  2. Also it’s possible to select all commits that belongs to this branch after creation from the parent branch and don’t select count of them by hands with the following:

    git rebase -i git merge-base --fork-point master
    

    It’s useful if you want to do that prior to merge

Wrap your code in <pre class="{language}"></pre> tags, link to a GitHub gist, JSFiddle fiddle, or CodePen pen to embed!