# Opinionated Git
## The Happy Path

---

## 🎯 Goals

- ✍️ Establish guiding principles for Git usage
- 🛠 Introduce tools aligned with these principles
- 🤔 Have fun solving puzzles!

---

## 🙀 Anti-goals

- A complete overview of the Git API or internals
- An explanation of more complex branching models, such as [git flow](https://nvie.com/posts/a-successful-git-branching-model/)
- "Advanced" git-fu and how to get out of common git conundrums (planning a separate workshop for this)

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## ✍️ Guiding Principles

- **`master` is the source of truth** and should be production-ready at all times
- **`feature` branches track work in progress** and should be short-lived
- **`git log` tells the story of our product** and should be linear

---

## 🏁 Let's get started!

1. Make sure `git` is [installed on your machine](https://git-scm.com/book/en/v2/Getting-Started-Installing-Git)
1. Install [pivotal workstation setup](https://github.com/pivotal/workstation-setup)
1. Clone the workshop repository

git clone https://github.com/simon-parker/git-workshop
cd git-workshop

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## 🛠 Reading `git log` output

git log --oneline --decorate --all --graph # aka `git lola`

- `HEAD` is your current location in the repository
- `(master, branch)` show your **local** branches/tags.
- `(origin/master, origin/branch)` show your **remote tracking** branches/tags.

---

## 🛠 Moving about

git checkout <commitish>

`<commitish>` can be a number of things, including:

- `git checkout <commit-hash>`
- `git checkout <branch-or-tag-name>`
- `git checkout <commitish>~1`
- `git checkout <commitish>~`

---

## 🤔 Puzzle Time! (5 minutes)

Try to solve the puzzle as efficiently as you can!

cd puzzles/checkout-them-all
source init

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## 🛠 Creating commits

git add . 
git add "src"
git add "*.sh" 
git add "*/test/*" 

git commit -m "commit message"
git commit --amend -m "amended commit"

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## 🛠 Creating new branches

git checkout -b new-branch

The new branch will appear at `HEAD`

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## 🤔 Puzzle Time! (5 minutes)

cd puzzles/branch-gardening
source init

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## 🛠 Rebasing: a fork in the road

What situation led to this branching?

digraph hierarchy {
                nodesep=0.5 // increases the separation between nodes
                node [shape=box, style=rounded]
                //rankdir=LR;
                
                master, feature [style="square", color="red"]
                
                
                feature -> "feature commit" -> "shared commit"
                master -> "master commit" -> "shared commit"
}

---

## 🛠 Rebasing: linear history

git checkout feature-branch
git rebase master

digraph hierarchy {
                nodesep=0.5 // increases the separation between nodes
                node [shape=box, style=rounded]
                //rankdir=LR;
                
                master, feature [style="square", color="red"]
                
                
                feature -> "feature commit" -> "master commit" -> "shared commit"
                master -> "master commit"
}

✍️ Rebasing makes our history easy to understand by making it **linear**!

---

## 🛠 Merging

✍️ We are not done until our changes are on `master`, the **source of truth**!

git checkout master
git merge feature

digraph hierarchy {
                nodesep=0.5 // increases the separation between nodes
                node [shape=box, style=rounded]
                //rankdir=LR;
                
                master, feature [style="square", color="red"]
                
                
                feature, master -> "feature commit" -> "master commit" -> "shared commit"
}

---

## 🛠 Merging: cleaning up

✍️ Once our changes are on our **source of truth**, we should delete our **short-lived feature branch**.

git checkout master
git merge feature
git push master
git branch -D feature     # delete local branch
git push --delete feature # delete remote branch

# delete any remote tracking branches 
# others have deleted with git push --delete
git fetch -p 

---

## 🤔 Puzzle Time! (10 minutes)

cd puzzles/rebase-madness
source init

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## 🎁 Bonus: The `-` shortcut

Like `bash`, Git will treat a `-` as an alias for your previous location in the tree

It works with `git checkout`, `git rebase` and `git merge`!

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## 🤔 What does this do?

git checkout feature-branch
# ... do some work
git checkout master
git pull -r

git checkout -
git rebase -
git checkout -
git merge -

git push

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## 🤔 Puzzle Time! (10 minutes)

It's time to bring together everything we learned and go through a full day in the life of a pair!

cd puzzles/day-in-the-life
source init

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## 🎉 Thank you!

🙏 In the spirit of continuous improvement, <a href="mailto:[e-mail]?subject=Git (Happy Path) Feedback&body=One thing I learned was: %0A%0AOne way the workshop can be improved in the future: ">please send me an e-mail</a> with the following feedback:

- One thing you learned during this workshop
- One way it can be improved in the future

😎 **That's all, folks!** 😎

---

## 📝 References

- [Trunk-Based Development](https://trunkbaseddevelopment.com/)
- [Git Documentation](https://git-scm.com/)
- [Pivotal Workstation Setup](https://github.com/pivotal/workstation-setup)
- [Explain Shell](https://explainshell.com/explain?cmd=git+log+--oneline+--graph+--decorate+--all)