PA 6: Merge Conflicts

Using GitHub

In this practice activity, you will be working in groups to create a new GitHub repository. You will practice pushing, pulling, and resolving conflicts as a team.

WarningIMPORTANT

This activity will only work if you follow the directions in the exact order that I have specified them. Do not work ahead of your group members!

Get into Groups!

Form groups of four people. Designate each person one of the suits:

As you work through the activity, you will complete the steps assigned to your suit. Make sure you complete the steps in order and only complete the steps assigned to you!

Note

If you only have 3 group members here, assign one person both and .

Repository Setup

1. Create a Repo on GitHub.

  • Create a new Github repo: Repositories > New .
    • Name the repo stat331-PA6.
    • You can choose to make it Public or Private.
    • Select .gitignore template: R.
  • After creating the repo, go to Settings > Collaborators > Add people.
    • Add your group members using their username or email.

2. Access the Remote Repo.

  • Accept the repo invite in your email – View invite > Accept invite.
  • Open the repo on GitHub.

3. Clone the Remote Repo Locally.

  • In Rstudio: File > New Project > Version Control > Git.
  • In GitHub: click <> Code and copy the HTTPS address.
  • In Rstudio: paste the address as the Repository URL. Leave the directory name box blank.
  • Click Browse and create this new project on your desktop.
    • Do not save this in your STAT 331 folder!!! We don’t want to embed an Rproj within another Rproj.
  • Create Project.

Collaborating in GitHub

4. Add Documents to the Repo.

  • In RStudio, create a new Quarto file.
    • If the Quarto file is totally blank (no default content), then add a single code chunk with 1 + 1.
    • Change the title to “Practice Activity 6”.
    • Resist the urge to add authors.
    • Save as PA6.qmd in your new stat331-PA6 folder on your desktop.
    • Add embed-resources: true to the YAML.
    • Keep the default template as is.
    • Render the document.
  • In RStudio, open and edit the .gitignore file to include *.Rproj and *.html.

Your directory stat331-PA6 should have the following files:

  • .gitignore
  • PA6.qmd
  • PA6.html
  • stat331-PA6.Rproj

Your Git window, should only show the following files:

  • .gitignore
  • PA6.qmd

If more than this shows up, then your .gitignore was not completed correctly! Git should be ignoring PA6.html and stat331-PA6.Rproj for tracking.

5. Push Documents to GitHub.

  • Rstudio: Git pane.
    • Stage (checkmark) the .gitignore > Commit ✅ > add a commit message (“ignore all .Rproj files and .html files”) > Commit > Close.
    • Stage (checkmark) PA6.qmd > Commit ✅ > add a commit message (“create PA quarto file”) > Commit > Close.
  • Rstudio: Git pane > Push (green arrow ⬆) the changes to the remote repo.

Git window in Rstudio with one Staged document README.md and a circle around the Commit comand.

Staged file ready to commit. Don’t forget to actually commit before pushing!

6. Pull Changes from GitHub.

  • Rstudio: Git pane > Pull (teal arrow ⬇) the changes that were made!

Everyone should now have the .qmd and updated .gitignore files in their local repo!

  • Look in your Files pane to make sure.

7. Make a Change.

  • Directly under the title: line, add author: to the YAML and include everyone’s first names.
  • Render the document.
  • Rstudio: Git pane > Stage (checkmark) files > Commit ✅ > add commit message > Commit > Close.
    • Use a commit message like “add first names”.
  • Rstudio: Git pane > Push ⬆ the changes.

8. Forget to Pull.

Do NOT pull the changes that were made!

9. Make the Same Change.

  • Directly under the title: line, add author: to the YAML and include everyone’s first and last names.
  • Render the document.
  • Rstudio: Git pane > Stage (checkmark) files > Commit ✅ > add commit message > Commit > Close.
    • Use a commit message like “add first and last names”.
  • Rstudio: Git pane > Push ⬆ the changes.
WarningOh No!

You got an error! Ugh. We forgot to pull before we started making changes.

Image of error with attempted Push when the local repo is not up to date with the remote repo.

10. Resolve the Merge Conflict.

Rstudio: Git pane > Pull ⬇ the changes from the repo.

Caution🚨 READ THIS - DO NOT IGNORE - did it work?? 🚨

If your Git Pull window does NOT look like this…

Rstudio Git Pull window with merge conflict.

but maybe it looks like this:

Git window error when cannot complete merge.

then…

  1. copy-paste the first command: git config pull.rebase false into the Terminal pane (not the Console) in RStudio and hit Enter,

Terminal Rstudio pane with git config pull.rebase false command.

Image showing the command in the Terminal pane of Rstudio.
  1. and Pull ⬇ again.

After sucessfully starting the pull and getting the message about a merge conflict…

Your Quarto file should now look like this…

Header YAML with git conflict symbols.

Tip

Note how the conflicting lines are marked! You might need to submit this to Canvas…

  • Edit the .qmd file to resolve the conflict with your preferred change.
    • This means deleting all of the symbols marking the conflict and just leaving your preferred change.
  • Render.
  • Note that in the Rstudio Git window, your files will be marked with “U”s to indicate a merge conflict.

Rstudio Git pane with file that is edited after a merge conflict.

  • ⚠️ the “Staged” box is also fully blue. This is a bit misleading – you still need to select the file to be staged to Stage it – make sure there is a CHECK mark in the staged box! The orange Us will then go away.
  • Commit ✅ your changes with a good commit message.
  • Push ⬆ your changes to GitHub.

11. Forget to Pull.

Do NOT pull the changes that were made!

12. Make a Different Change.

  • Edit the first code chunk to find the product of \(13 \times 13\).
  • Render the document.
  • Stage and Commit ✅ your changes and Push ⬆ your changes to GitHub.
Warning

You will get an error, read it and Pull ⬇ .

  • No merge conflicts should occur – the changes were auto-merged!
    • Your merge may have been made by a different strategy, but that’s okay.

Git Pull window after a successful merge.

  • Push ⬆ your changes again.

13. Forget to Pull.

Do NOT pull the changes that were made!

14. Make the Same Change (Again).

  • Edit the first code chunk to find the product of \(11 \times 11\).
  • Render the document.
  • Stage and Commit ✅ your changes and Push ⬆ your changes to GitHub.
Warning

You will get an error. Ugh!!!! We forgot to pull again!

  • Pull ⬇ the changes from GitHub.
  • Edit the .qmd file to resolve the conflict with the preferred change.
  • Stage and Commit ✅ your changes and Push ⬆ your changes to GitHub.

15. Final Document

Pull ⬇ the changes and look at your final document.

TipCanvas Quiz Submission

How does Git mark the start of lines with a merge conflict?

  • Specifically, I want the four capital characters with which every conflict is marked.