Git Branching Strategies

# === Create branch ===
git branch feat/login          # Create (stay on current branch)
git checkout -b feat/login     # Create + switch (classic)
git switch -c feat/login       # Create + switch (modern, preferred)

# === Switch branch ===
git checkout main              # Switch to main (classic)
git switch main                # Switch to main (modern)
git switch -                   # Toggle between last 2 branches

# === List branches ===
git branch                     # Local branches
git branch -a                  # Local + remote
git branch -v                  # Last commit on each branch
git branch --merged main       # Branches already merged into main
git branch --no-merged main    # Branches NOT yet merged

# === Delete branch ===
git branch -d feat/login       # Safe delete (fails if unmerged)
git branch -D feat/login       # Force delete
git push origin --delete feat/login  # Delete remote branch

# === Rename branch ===
git branch -m old-name new-name        # Rename local
git branch -m main                     # Rename current to main

# === Track remote branch ===
git checkout -b feat/login origin/feat/login
git push -u origin feat/login  # Set upstream tracking

# === See where branches diverged ===
git log --oneline --graph --all

# === Conflict markers in the file ===
<<<<<<< HEAD (Current Change)
const port = 8080;       # Your change on main
=======
const port = 3000;       # Incoming change from branch
>>>>>>> feat/dev-server

# === Resolve: choose one, or combine ===
const port = process.env.PORT || 8080;  # Best: combine both intentions

# === After editing ===
git add file.js          # Mark as resolved
git commit               # Complete the merge

# === Abort if too complex ===
git merge --abort        # Go back to before the merge
git rebase --abort       # Go back to before the rebase

# === See all conflicted files ===
git diff --name-only --diff-filter=U

# === Use VS Code's merge editor ===
code .                   # Open in VS Code
# Click "Resolve in Merge Editor" on conflicted files
# Choose: Accept Current | Accept Incoming | Accept Both

# === Prevent conflicts: sync often ===
git fetch origin
git rebase origin/main   # Replay your branch on latest main

# === 1. Sync from latest main ===
cd my-devops-app
git switch main
git pull origin main
git log --oneline -3    # Confirm you have latest

# === 2. Create feature branch ===
git switch -c feat/add-health-endpoint
git branch              # Confirm you're on new branch

# === 3. Commit 1: Add healthcheck script ===
cat > healthcheck.sh << 'EOF'
#!/bin/bash
echo "Status: OK"
echo "Version: 1.0.0"
echo "Timestamp: $(date -u +%Y-%m-%dT%H:%M:%SZ)"
echo "Hostname: $(hostname)"
EOF
chmod +x healthcheck.sh
git add healthcheck.sh
git commit -m "feat: add health check script"

# === 4. Commit 2: Update README ===
echo "" >> README.md
echo "## Health Check" >> README.md
echo "Run: \`./healthcheck.sh\`" >> README.md
git add README.md
git commit -m "docs: document health check endpoint"

# === 5. Push branch to GitHub ===
git push -u origin feat/add-health-endpoint
# → GitHub shows "Compare & pull request" — click it!
# → Add title: "feat: add health endpoint"
# → Add description (why? what? how tested?)
# → Open the Pull Request

# Branch name pattern: main

# Recommended settings for GitHub Flow:
✅ Require a pull request before merging
   - Required approvals: 1 (min)
   - Dismiss stale reviews when new commits pushed
   - Require review from code owners (if CODEOWNERS exists)

✅ Require status checks to pass before merging
   - Search for your CI workflow name and add it
   - Require branches to be up to date before merging

✅ Require conversation resolution before merging
   - All review comments must be resolved

✅ Do not allow bypassing the above settings
   - Even admins can't force-push

✅ Restrict who can push to matching branches
   - Only allow designated deployers

# Allowed merge strategies:
✅ Allow squash merging    ← Recommended for GitHub Flow
❌ Allow merge commits     ← Optional, disable for clean history
❌ Allow rebase merging    ← Optional

# Auto-delete:
✅ Automatically delete head branches after merge

### EVERY TIME you start work ###
git switch main
git pull origin main           # Always sync first
git switch -c feat/my-feature  # Create from latest main

### WHILE working ###
git status                     # Check what's changed
git add -p                     # Stage carefully
git commit -m "feat: ..."      # Conventional commit
git push origin feat/my-feature # Push (creates remote)

### Keep branch fresh (do daily) ###
git fetch origin
git rebase origin/main         # Stay close to main

### Open PR on GitHub ###
# Write clear title + description
# Link to issue: "Closes #42"
# Request review from teammate

### After PR is merged ###
git switch main
git pull origin main           # Get the merged commit
git branch -d feat/my-feature  # Delete local branch
git fetch --prune              # Clean remote tracking refs

### Emergency hotfix ###
git switch main
git pull origin main
git switch -c hotfix/prod-500-error
# Fix the issue
git commit -m "fix: resolve 500 on /api/login"
git push -u origin hotfix/prod-500-error
# Open PR → get FAST review → merge ASAP