Collaborating with GitHub

Objective

Learners will fork and clone a repository on GitHub and use branches to open pull requests.

Lesson Outline

• Review Homework:

  • Anyone put a repo on GitHub? Any difficulties encountered?

• Live Coding: Collaborating with GitHub

  • Share a repo with everyone & have everyone clone w/ RStudio
  • Ask 1 (one) volunteer to make a change and practice commit + push
  • Instructor makes commit + push, volunteer pulls

• Live Coding: Merge conflict

  • Instructor makes commit to README and pushes to GitHub
  • Volunteer makes commit to the same line of README and pushes without pulling first
  • Should error for volunteer

• Slides: Resolving merge conflict

• Live Coding: Resolve merge conflict

  • Try following the hints in the error and pull
  • New error about divergent branches
  • Then have everyone set git config pull.rebase false

• Working on branches (slides)

• Live Coding:

  • Make a branch with your name in RStudio
  • Add your name to README and commit
  • Switch between branches and see the file change in RStudio AND in File Explorer / Finder
  • Push & see branches on GitHub

• Pull Requests (slides)

• Live Coding:

  • Have everyone make a PR to add their name to the README
  • Demo merging one or two & ask volunteer to resolve any merge conflicts

• Forks (slides)

  • Discuss when you would work on a branch of a fork vs. working in a branch but on the same repo

• Live Coding:

  • Have students create a fork of a second example repo and clone their fork
  • In pairs, have them practice making a branch, making changes, commit + push, and make a PR on GitHub

• Homework:

  • Maybe try cloning a repo that you don’t have permission to push to to see what happens

  • Try using usethis::pr_finish() on a branch that was already merged on GitHub and take note of what it does