git challenge

Instructions

This exercise will take you through a standard git workflow on your computer and on a whiteboard.

Do this exercise in pairs. Choose one student to work at their computer while the other student manages their whiteboard. When you’ve completed the exercise once through, swap roles and start over.

Begin by drawing four boxes on your whiteboard. Label them working directory, staging area, local repo and remote repo.

1. Clone the repo

This exercise begins with a repo on GitHub. Visit https://github.com/eds-221-programming-m26/eds221-git-challenge in your browser to see what the repo looks like. You should see a README file containing the same instructions as the page on the course website.

Cloning copies a remote repository on GitHub to a local repository on your computer.

At your computer

First, make your own copy of this remote repo.

  1. On the repo page, click the green “Use this template” button → “Create a new repository.”.
  2. Keep the owner your own GitHub account and use the same repo name eds221-git-challenge.
  3. Click “Create repository.

Then, clone your copy of the remote repo to your computer.

  1. Switch to the Terminal in Positron (not the R console).

  2. cd to your eds221/ directory (not your eds221-day1pm/ directory; one level up from there).

  3. Clone the remote repo with this command:

    git clone https://github.com/<your GitHub username>/eds221-git-challenge

Make sure to replace <your GitHub username>. You should now see the directory eds221/eds221-git-challenge/.

At your whiteboard

  1. Draw a line from your remote repo box to your working directory box.
  2. Label the line git clone.

2. Make changes in your working directory

The working directory is the directory on your computer that git recognizes as a repository. git will track your changes as you edit, create, and delete files in this directory.

At your computer

  1. Open the eds221/eds221-git-challenge/ folder in Positron.
  2. Edit the README. Add a sentence stating your name and the name of your favorite video game from childhood. If you didn’t play video games, pick another kind of game (board, card, sport, etc).
  3. Save the README.
  4. Create directory called R/.
  5. Create a script in R/ called fave-game.R. Add these expressions to your script, replacing the text as appropriate.
my_fave_game <- "your favorite childhood game here"
paste("my favorite childhood game was", my_fave_game)
  1. At the terminal, run git status. You should see that README.md and R/ have been modified. If they haven’t, make sure you saved your changes.

Note: only R/, rather than R/fave-game.R, shows up now because the directory is new. After you stage individual files, you’ll see the full paths show up.

At your whiteboard

  1. Write README.md and R/fave-game.R on sticky notes.
  2. Place the sticky notes in the working directory box.

3. Stage your changes

If using git is like working in a kitchen, then the staging area is the countertop. It’s where you put your ingredients (file changes in the working directory; the previous step) before you cook with them (committing changes; the next step).

At your computer

  1. At the terminal, run git add README.md.
  2. Run git status again. Verify that README.md is under “Changes to be committed”, but R/ is still in “Untracked files”.

At your whiteboard

  1. Move the README.md sticky note to the staging area box.

At your computer

  1. At the terminal, run git add R/fave-game.R.
  2. Run git status again. Verify that both README.md and R/fave-game.R are under “Changes to be committed”.

At your whiteboard

  1. Move the R/fave-game.R sticky note to the staging area box.

4. Commit your changes

You’ve pulled out your ingredients, now it’s time to cook. Committing your changes creates a new checkpoint in your local repository. It’s the equivalent of an entry in a Wikipedia page revision history.

At your computer

  1. At the terminal, run git commit -m "Add favorite game".

The -m "Add favorite game" part defines your commit message. It’s a brief summary of the changes included in the commit.

  1. Run git status again. Verify that you see “Your branch is ahead of ‘origin/main’ by 1 commit”, which means your local repository has a commit that isn’t on the remote repository yet. Also verify that you see “nothing to commit, working tree clean”, which means that your working directory and local repository are synced up.

At your whiteboard

  1. Move the README.md and R/fave-game.R sticky notes to the local repository box together. This represents all the staged changes getting packaged up in a single commit.

5. Push your changes

You’ve cooked the meal, but no one can eat because you haven’t served it yet. Pushing your commit will send your local changes to the remote repository on GitHub. At that point, collaborators and clients will be able to see your work.

At your computer

  1. At the terminal, run git push. You should see messages about enumerating, counting, compressing, and writing objects. These all mean the commit is making its way from your computer up to the remote repository.
  2. Run git status. You should see a local repository looking very content and pleased with itself. That looks like this:
On branch main
Your branch is up to date with 'origin/main'.

nothing to commit, working tree clean

At your whiteboard

  1. Move the README.md and R/fave-game.R sticky notes to the remote repository box.