Git & GitHub Essentials

If you skip this section, you'll create noise instead of value. Version control is the universal language of open source.

Why This Matters

35% of PR rejections come from poor Git practices: messy commits, merge conflicts, wrong branches.

What You'll Learn

Topic	Why It Matters	Time
Git Basics	Foundation for everything	30 min
Branching Strategy	Organize your work	20 min
Commit Messages	Communication through code	15 min
Syncing Fork	Stay up-to-date	15 min
Merge Conflicts	Handle the inevitable	25 min
Rewriting History	Clean up your work	20 min
Force Push	Know the dangers	10 min

The Git Mental Model

Key Concepts Overview

Repository Structure

your-project/
├── .git/                 # Git metadata (don't touch!)
│   ├── config            # Remote URLs, settings
│   ├── HEAD              # Current branch pointer
│   ├── objects/          # All commits, files
│   └── refs/             # Branch pointers
├── src/                  # Your code
└── README.md

The Three States of Files

State	Meaning	Command to Move
Untracked	Git doesn't know about it	`git add`
Staged	Ready to be committed	`git commit`
Committed	Saved in history	(edit file)
Modified	Changed since last commit	`git add`

Essential Commands Cheat Sheet

Daily Workflow

git status              # What's changed?
git add .               # Stage everything
git commit -m "msg"     # Save changes
git push                # Upload to GitHub
git pull                # Download updates

Branching

git branch              # List branches
git checkout -b name    # Create & switch
git checkout main       # Switch to main
git merge branch        # Merge branch

Syncing

git fetch upstream      # Get upstream changes
git merge upstream/main # Merge them
git push origin main    # Update your fork

Common Mistakes to Avoid

❌ Don't Do This

# Committing to main directly
git checkout main
git commit -m "my feature"  # ❌ NO!
 
# Force pushing to shared branches
git push --force origin main  # ❌ DANGEROUS!
 
# Giant commits with everything
git add .
git commit -m "stuff"  # ❌ Meaningless

✅ Do This Instead

# Work on feature branches
git checkout -b feature/add-login
git commit -m "feat: add login form"  # ✅
 
# Only force push YOUR feature branches
git push --force origin feature/my-branch  # ✅ OK
 
# Atomic, meaningful commits
git add src/login.js
git commit -m "feat(auth): add login form validation"  # ✅

Self-Assessment

Before proceeding, you should know:

Score yourself:

5/5 → Skip to Syncing Fork
3-4/5 → Start with Git Basics
0-2/5 → Read everything carefully

Tools to Help

GUI Clients

Tool	Platform	Best For
GitHub Desktop	Win/Mac	Beginners
GitKraken	All	Visual learners
VS Code Git	All	Editor integration
Sourcetree	Win/Mac	Advanced users

Terminal Enhancements

# Oh My Zsh git plugin
alias gs="git status"
alias gc="git commit"
alias gp="git push"
alias gl="git log --oneline"

Learning Path

Estimated total time: ~2.5 hours

Quick Reference Card

Creating a PR Workflow

Next Steps

Ready to dive in? Start with the first topic:

➡️ Git Basics You Must Know →

Pro Tip: Bookmark this page. You'll reference these commands hundreds of times in your open source journey.

Choosing Issues Git Basics