modules

Git: Forking

Key Terms

• fork - make a copy of a remote repo on GitHub from one account to another.
• pull request - ask the upstream maintainer to pull in changes from origin.
• upstream - the name for a remote read-only repository
• origin - the name for a remote read-and-write repository

A Typical Setup for Forked Code

Branching vs Forking

• Branching is a feature of Git, you’ve used branching already
• Forking is a feature of GitHub
  • A fork is a personal copy of another user’s repository that lives on your account. Forks allow you to freely make changes to a project without affecting the original. Forks remain attached to the original, allowing you to submit a pull request to the original’s author to update with your changes. You can also keep your fork up to date by pulling in updates from the original. - GitHub Glossary
  • When you fork a repository, you get all of the branches the other person posted on GitHub
  • Pull requests however, don’t acknowledge forks since they are a feature of GitHub and not Git. So while you can colloquially say “I’m issuing a pull request from my fork to yours”, really what you’re saying is “I’m issuing a pull request from the master branch of my fork to the master branch of your fork”. You can actually issue a pull request from any branch in your forked repository to any branch in the original repository.

Here is a good example repository that makes use of issues and pull requests: https://github.com/openelections/

❇️ Example (shorter - no local repository)

1. Step 1: Fork my repository dmil/simple-website.

2. Go to Settings > GitHub Pages and select the “master” branch as the source. Wait a few seconds and then go to http://your-username.github.io/simple-website to make sure github pages is set up correctly.

3. Normally I’d clone the forked repository locally onto my computer, push changes to the fork, then issue a pull request. For the sake of time lets cut that step out. Make one small edit in your fork of this code directly in GitHub.

4. Create a pull request. Note that this time we are creating pull request across repositories instead of just across branches within the same repository. The base will be dmil/simple-website/master while the compare will be your-username/simple-website/master.

5. Compare your website http://your-username.github.io/simple-website to mine: http://dhrumilmehta.com/simple-website/

6. I will now merge your pull requests and we can see what changes you all make to the website over time. There’s a good chance we may run into some merge conflicts as well.

❇️ Example (Longer)

1. Step 1: Fork my repository dmil/simple-website.

2. Go to Settings > GitHub Pages and select the “master” branch as the source. Wait a few seconds and then go to http://your-username.github.io/simple-website to make sure github pages is set up correctly.

3. Clone the forked repository to your Development folder.

    git clone git@github.com:XXXX/XXXX.git
   

4. Create a feature branch with your name.

    git checkout -b <your name>
   

5. Make a random change.

6. Commit and push the change.

    git commit -m "describe your random change here"
    git push
   

7. Create a pull request. Note that this time we are creating pull request across repositories instead of just across branches within the same repository. The base will be dmil/simple-website/master while the compare will be your-username/simple-website/feature-branch-name.

8. Create another pull request within the fork itself where the base is your own master branch. More explicitly, the base is your-username/simple-website/master and the compare is your-username/simple-website/feature-branch-name. Merge this pull request.

   Note: Draw diagram on board

9. Compare your website http://your-username.github.io/simple-website to mine: http://dhrumilmehta.com/simple-website/

10. I will now merge your pull requests and we can see what changes you all make to the website over time. There’s a good chance we may run into some merge conflicts as well.

Woohoo! You just collaborated open-source.

Open source collaboration is great for:

• Not duplicating work
• Collaborating accross organizations
• Interacting with people - sometimes making an issue or a pull request can lead to friendship (or sources or collaborators)
• Reader feedback
• Collective debugging, finding critical errors faster (often also leads to better security and better data quality).
• Building upon someone else’s project
• Feuding
• Philosophical Reasons
• Being nerdy?

More Links

• https://government.github.com/
• https://government.github.com/community/

➡️ Try It

1. Find another partner, and fork their <username>-simple-website.
2. Clone your fork onto your local computer and create a feature branch called endorsement.
3. Put an endorsement on their webpage as the last item on the site.

    <h2> Endorsements </h2>
    <p> You are a really cool person. - Dhrumil</p>
   

4. Commit this endorsement and push it to your fork..
5. Issue a pull request back to that person’s github repo.

Pull Requests and Issues in the Wild

• https://github.com/tj/git-extras/pull/356
• https://github.com/powmedia/backbone-forms/issues/537
• https://github.com/powmedia/backbone-forms/pull/538

➡️ Try It

Make an issue on my simple-website repository: https://github.com/dmil/simple-website