Git & GitHub for Developers

# Check what's changed
git status

# See the actual changes
git diff                    # unstaged changes
git diff --staged           # staged changes

# Stage specific files
git add src/components/Button.tsx
git add src/             # all files in src/

# Never use git add . without checking git status first
# (might accidentally commit .env, node_modules, etc.)

# Commit with a meaningful message
git commit -m "feat: add enrollment button to course page"

# Push to GitHub
git push origin main
git push origin feature/user-dashboard   # push a feature branch

type: short description (under 72 characters)

Optional longer explanation.

feat:     New feature
fix:      Bug fix
docs:     Documentation only
style:    Formatting, no logic change
refactor: Code change, no feature or fix
test:     Adding or updating tests
chore:    Build, tooling, deps

feat: add dark mode toggle to navigation
fix: prevent duplicate enrollment when clicking twice
refactor: extract PaymentForm into its own component
chore: upgrade Next.js to 15.2

# Create and switch to a new branch
git checkout -b feature/enrollment-flow

# Do your work, commit...
git add .
git commit -m "feat: add enrollment modal"
git commit -m "feat: add payment form validation"

# Push the branch to GitHub
git push origin feature/enrollment-flow

# Open a pull request on GitHub, get it reviewed, merge it

# Back to main, pull the latest changes
git checkout main
git pull origin main

# Delete the merged branch
git branch -d feature/enrollment-flow

<<<<<<< HEAD
const buttonColor = "blue";
=======
const buttonColor = "indigo";
>>>>>>> feature/redesign

# Check which files have conflicts
git status

# After resolving, mark as resolved
git add src/components/Button.tsx
git commit -m "merge: resolve button color conflict"

# Unstage a file (before commit)
git restore --staged src/components/Button.tsx

# Discard changes to a file (back to last commit)
git restore src/components/Button.tsx

# Undo last commit, keep changes staged
git reset --soft HEAD~1

# Undo last commit, keep changes unstaged
git reset HEAD~1

# View the git history
git log --oneline --graph

# Revert a specific commit (creates a new commit that undoes it — safe for shared branches)
git revert abc1234

# Stash current changes
git stash

# Switch branches, do something else, come back

# Restore your stashed work
git stash pop

# See what's stashed
git stash list

# Stash with a description
git stash push -m "half-done enrollment flow"

# Apply a specific stash
git stash apply stash@{1}

# Install GitHub CLI
gh auth login

# Create a PR
gh pr create --title "feat: add enrollment flow" \
    --body "Adds the full enrollment modal with Stripe payment integration.

Closes #42

## Changes
- New EnrollmentModal component
- Stripe payment form
- Success/error states

## Testing
1. Click 'Enroll Now' on any course page
2. Fill in the payment form with test card 4242 4242 4242 4242
3. Verify redirect to dashboard"

# View open PRs
gh pr list

# Check out a PR to review locally
gh pr checkout 42

# .gitignore

# Dependencies
node_modules/

# Environment variables — NEVER commit these
.env
.env.local
.env.production

# Build output
.next/
dist/
build/

# OS files
.DS_Store
Thumbs.db

# Logs
*.log
npm-debug.log*

# IDE settings
.vscode/settings.json
.idea/

# Upload directories
public/uploads/

# Add to ~/.gitconfig or run as git config --global
git config --global alias.st status
git config --global alias.co checkout
git config --global alias.br branch
git config --global alias.lg "log --oneline --graph --decorate --all"

# .github/workflows/ci.yml
name: CI

on:
  push:
    branches: [main]
  pull_request:
    branches: [main]

jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          node-version: "20"
          cache: "npm"
      - run: npm ci
      - run: npm run lint
      - run: npm test
      - run: npm run build