ETC5513: Collaborative and Reproducible Practices

Tutorial 5

Author

Michael Lydeamore

Published

16 April 2025

🤝 Exercise 1: Forking and Pull Requests in Pairs

In this exercise, you’ll work with a partner to practice real-world collaboration on GitHub.

You’ll learn how to:

  • Fork a GitHub repo created by your teammate
  • Make a change
  • Submit a pull request (PR)
  • Review and merge someone else’s PR

🧑‍🤝‍🧑 Step 1: Pair Up

Assign roles in your pair:

  • Student A = Repository Owner
  • Student B = Contributor (forks and submits a pull request)

You’ll switch roles after completing the exercise.

🛠️ Step 2: Student A – Create a Starter Repository

  1. Go to https://github.com and log in.

  2. Click + → New Repository

  3. Name the repository something simple, like collab-demo

  4. ✅ Check Add a README file

  5. Click Create Repository

  6. Share the URL of the repository with Student B

  7. Now clone the repository to your own computer:

    • Click the green Code button → choose SSH and copy the URL
    • In your terminal:
    git clone git@github.com:your-username/collab-demo.git
cd collab-demo

  8. Create a new RStudio Project in an existing directory:

    • Open RStudio
    • Go to File → New Project → Existing Directory
    • Browse to the folder you just cloned (e.g., collab-demo)
    • Click Create Project

  9. Add, commit and push the .Rproj file that gets created:

    git add .Rproj
git commit -m "Add .Rproj file"
git push origin main

✅ Done! Your repository is ready for your partner to fork and contribute.

🍴 Step 3: Student B – Fork and Contribute

  1. Open the repo link your partner (Student A) shared.

  2. Click the “Fork” button (top-right corner).

  3. On your forked copy, click Code → SSH and copy the URL.

  4. Open your terminal and clone your fork:

git clone git@github.com:your-username/collab-demo.git
cd collab-demo

  1. Open this folder in RStudio and edit the README file to include your name

  2. Save the file, then stage, commit, and push:

git add README.md
git commit -m "Add line to README"
git push origin main
  1. Go back to your forked repository on GitHub.
    Click “Compare & pull request”, then Create pull request.

✅ You’ve submitted your contribution!

✅ Step 4: Student A – Review and Merge the Pull Request

  1. Go to your original repository on GitHub.
  2. You should see a new pull request from your partner.
  3. Click it → Review the changes.
  4. Click Merge pull request, then Confirm merge.
  5. (Optional) Delete the branch after merging.

🎉 Your teammate’s changes are now part of the main repository!

🔁 Step 5: Switch Roles

Switch roles so both students get experience creating, forking, and merging.

🍴 Exercise 2: Fork a Public Repository and Make a Pull Request

In this exercise, you’ll practice contributing to an existing project by:

  • Forking a public repository
  • Making a simple contribution
  • Submitting a pull request (PR)

📦 Step 1: Fork the Repository

  1. Go to this GitHub repository:
    👉 https://github.com/numbats/rcp

  2. In the top-right corner, click the “Fork” button.

  3. GitHub will create a copy of the repo in your account.

💻 Step 2: Clone Your Fork

  1. On your forked repository page, click the green Code button.

  2. Select SSH, then copy the URL.

  3. Open your terminal and run:

git clone git@github.com:your-username/rcp.git
cd rcp

📝 Step 3: Add Your File

Inside the project, you’ll see a folder called student-record.

  1. Create a new file in that folder using your GitHub username. For example:
touch student-record/MikeLydeamore.md
  1. Open the file and add a simple message:
Hi, I’m MikeLydeamore on GitHub! Here’s my contribution to the rcp project.
  1. Save the file.

📬 Step 4: Commit and Push

  1. Stage and commit your file:
git add student-record/jamie-lee.md
git commit -m "Add jamie-lee.md to student-record"
  1. Push your changes to your fork:
git push origin main

✅ Step 5: Create a Pull Request

  1. Go back to your fork on GitHub.
  2. You should see a banner to “Compare & pull request” — click it.
  3. Confirm the changes, then click “Create pull request”

🎉 You’ve just submitted a real contribution to a public GitHub repository!

🧠 Why This Matters

This is how open-source collaboration works in the real world:

  • You fork a project
  • Make meaningful changes
  • Propose those changes via a pull request
  • Maintainers review and (hopefully!) merge your work

You’re now part of the open-source ecosystem 💪