Introduction to Git

Why Git?

• Linux Kernel
  • 15 million lines of code
  • 60 000 contributors
  • One central repository
• Was using SVN
  • Very Slow
  • Central point of failure

Originally Developed by Linus Torvalds

What is Git?

"Git is a Free and open source distributed version control system designed to handle everything from small to very large projects with speed and efficiency."

Distributed

Github

• Github is not Git
• Cloud service
• Central repository. Although Git is decentralized
• Extra features on top of Git
  • Pull requests
  • Visualisations
  • Permission management
  • Organizations

Tools

• Command line
  • Best way to do git. Most servers don't have a UI. 
  • Learn this first.
  • Unix users. Add small script to bash_profile to show current working branch
• Source tree
  • Drag-Drop UI
  • Good visual overview
  • Use it for the more complex interactions

SourceTree

Basic Concepts

• Clone  Make a local copy of a repository
  • ​When you want to make changes to the existing repo.
• Fork Make a clone of a repository. On github. Your own central version.
  • When you want to create your own version of an existing software project.
• Git init Create a new repository from existing folder
• Remote: Link to an external repository

Local modification

• Git status
• Git add
• Git commit 
• Git reset
• Git remove

Pushing and Pulling

Merge Conflicts

Branching & tagging

Git Stash

git stash

git stash pop

Undo Changes

• Never rewrite history
• Instead, use git revert
  • commits the inverse
• Use git rebase carefully!

Git Flow

• Model on how to do branching
• Industry Standard
• For World of Balance
  • Master - Latest Stable version
  • Hotfixes - Merges straight into master
  • Development - Unstable Branch
  • Feature branches - sub branch of development for specific features. Very unstable.

Feature Branches

• Every independent feature has a branch
• Branched off of Development
• Create pull request when you want to merge
• Review with team before you merge

Pull Requests

Github Issues

Releases

• Merge Development into Master
• Increase the tag number (Semver)
• Should (in theory) be stable

Think about other developers

Some tips and guidelines

• Never Merge into dev without Pull Request
• Definitely do not merge into Master
• When in doubt, create a feature branch
• Whitespace vs tabs.
• Feel free to experiment on branches
• Write clear commit messages
  • "Added a new animal class"
• • "Changed some text in some file"
• Use Github issues to communicate across teams
• Be careful with merge conflicts. Use git blame

Some Golden rules

Incase of broken code

• This is why we have version control.
• Integration team will fix it.
• Changes can always be reverted
• It's a class, not a million dollar project.

Questions?