Git Katas

Notes:

Those tasks should be worked on by teams of 2 people at least. We'll use Alice and Bob as names.

You should never use push --force or equivalent unless otherwise stated

You should be able to perform the tasks listed here using either the command line or a tool like sourcetree.

Task 0 - Clone this repo

The first task is to clone this repo in a place where you have write access.

You can either fork it on GitHub, or re-create it from scratch on GitLab for instance.

Task 1 - The cycle of collaboration

Goal: learn how to share a branch across the same team

Make sure Alice and Bob both have cloned the repo

• Alice: add your name to the THANKS
• Alice: make a commit with the message "Add Alice to THANKS file"
• Alice: push the commit to the main branch
• Bob: fetch Alice's changes from the main branch
• Bob: make a commit with the message "Add Bob to THANKS file"
• Bob: push the commit to the main branch
• Alice: update the main branch

Alice should end up with a log looking like this:

* 6430036 - Add Bob to THANKS file (62 seconds ago) <bob>
--- a/THANKS
+++ b/THANKS
@@ -1 +1,2 @@
 Alice
+Bob

* a6c829f - Add Alice to THANKS file (2 minutes ago) <alice>
-
+Alice

Task 2 - Two commits from one file

*Goal: learn about the git index *

This should be done by each member of the team.

• Change at least two different lines in index.html file (I'm sure you can find something to improve)

• Make two commits, each one containing a different line change.

Task 3 - Undoing changes

Goal: learn about the various ways to undo changes in git

This should be done by each member of the team.

• Revert the two commits made during task 2

• Change a few lines in index.html and then restore the file to its original version

• Move the head of the branch to where it was before task 2 started branch

Task 4 - Happy merge

Goal: show how to merge in the trivial case

• Alice: Change the <title> in index.html
• Alice: push the changes to the main branch
• Bob: do not fetch Alice's changes
• Bob: change something in the JavaScript code
• Bob: make a commit and try to push it to the main branch - git will ask your to merge first
• Bob: merge your branch and push the result

Task 4 bis - Happy rebase

Some as task 4, but use rebase so that there is no merge commit in the history.

Task 5 - Conflict resolution

Goal: learn about merging conflicting changes

• Alice: Edit 'conflict.txt' and add the following text on line 2:

C'est la goutte d'eau qui met le feu aux poudres

• Alice: make a commit and push it to the main branch

• Bob: make sure to not fetch Alice's changes at this point.

• Bob: Edit 'conflict.txt' and add the following line also on line 2:

C'est l'étincelle qui fait déborder le vase

• Bob: make a commit and try to push it to the main branch - git will ask your to merge first

• Bob: try and merge - git will tell you that there are conflicts

• Alice & Bob: resolve the conflict and push the resolution

Task 6 - Cherry-picking

If you look at the repo, you will see that the 'release' branch does not contain the commit that bumps the year in the COPYRIGHT file (which is expected since it was created in 2021).

Use cherry-picking to fix the COPYRIGHT year on the release branch as well

Task 7 - Rebase

Make three commits that each add one line in a distinct, existing file.

Use interactive rebase to put the commits in reverse order.

Harder: make three commits that each add one line to the index.html file so you end up with:

<ul>
  <li>one</li>
  <li>two</li>
  <li>three</li>
</ul>

Use rebase to put the commits in the order "one - three - two". You will have to solve conflicts during the rebase - have fun.

Task 8 - Code review

• Alice: Fix style issues in 'index.html'
• Alice: Make sure to include a typo in the code
• Alice: Make a commit and push it in a branch named 'fix-style'
• Alice: Create a merge request (GitLab) or a pull request (GitHub)
• Bob: look at Alice's changes and leave some comments about the typo
• Alice: Use rebase or git commit --amend to address Bob's feedback and fix the typo (you are allowed to use push --force this time)
• Bob: Merge Alice's branch