Git & GitHub

# Configuration
git config --global user.name "Your Name"
git config --global user.email "your@email.com"
git config --global init.defaultBranch main

# Initialize repository
git init                    # New repository
git clone <url>            # Clone existing repository

# Basic workflow
git status                  # Check status
git add <file>             # Stage specific file
git add .                   # Stage all changes
git add -p                  # Interactive staging

git commit -m "message"     # Commit with message
git commit -am "message"    # Stage tracked files and commit

# Viewing history
git log                     # Full log
git log --oneline           # Compact log
git log --graph --oneline   # Visual branch history
git log -p                  # With diffs
git log --author="name"     # By author

# Undo changes
git checkout -- <file>     # Discard working directory changes
git restore <file>         # Same as above (newer syntax)
git reset HEAD <file>      # Unstage file
git reset --soft HEAD~1     # Undo last commit, keep changes staged
git reset --hard HEAD~1     # Undo last commit, discard changes

# Diff
git diff                    # Working directory vs staged
git diff --staged           # Staged vs last commit
git diff HEAD~2             # Last 2 commits

# Branch operations
git branch                  # List local branches
git branch -a               # List all branches (including remote)
git branch <name>          # Create branch
git branch -d <name>       # Delete branch (merged)
git branch -D <name>       # Force delete branch

# Switching branches
git checkout <branch>      # Switch to branch
git checkout -b <branch>   # Create and switch
git switch <branch>        # New syntax for switching
git switch -c <branch>     # Create and switch (new syntax)

# Merging
git merge <branch>         # Merge branch into current
git merge --no-ff <branch> # Create merge commit even for fast-forward

# Resolve merge conflicts
# 1. Edit conflicted files
# 2. git add <resolved-files>
# 3. git commit

# Rebasing
git rebase <branch>        # Rebase current onto branch
git rebase -i HEAD~3       # Interactive rebase last 3 commits

# Cherry-pick
git cherry-pick <commit>   # Apply specific commit to current branch

# Remote management
git remote -v               # List remotes
git remote add origin <url>
git remote remove origin
git remote set-url origin <new-url>

# Fetching and pulling
git fetch                   # Download changes (no merge)
git fetch --prune           # Remove deleted remote branches
git pull                    # Fetch + merge
git pull --rebase           # Fetch + rebase

# Pushing
git push                    # Push to tracked branch
git push origin <branch>   # Push specific branch
git push -u origin <branch> # Set upstream and push
git push --force            # Force push (be careful!)
git push --force-with-lease # Safer force push

# Working with remote branches
git checkout -b local-branch origin/remote-branch
git branch --set-upstream-to=origin/branch

# Tags
git tag                     # List tags
git tag v1.0.0              # Create lightweight tag
git tag -a v1.0.0 -m "msg"  # Annotated tag
git push origin v1.0.0      # Push specific tag
git push origin --tags      # Push all tags

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

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

jobs:
  build:
    runs-on: ubuntu-latest
    
    steps:
      - uses: actions/checkout@v3
      
      - name: Setup Node.js
        uses: actions/setup-node@v3
        with:
          node-version: '18'
          
      - name: Install dependencies
        run: npm ci
        
      - name: Run tests
        run: npm test
        
      - name: Build
        run: npm run build

# Install: https://cli.github.com/
gh auth login               # Authenticate

# Repository
gh repo create              # Create repo
gh repo clone owner/repo    # Clone repo
gh repo view                # View repo info

# Pull Requests
gh pr create                # Create PR
gh pr list                  # List PRs
gh pr checkout <number>    # Checkout PR
gh pr merge                 # Merge PR
gh pr review                # Review PR

# Issues
gh issue create             # Create issue
gh issue list               # List issues
gh issue close <number>

# Stashing
git stash                   # Stash current changes
git stash save "message"    # Stash with message
git stash list              # List stashes
git stash pop               # Apply and remove latest stash
git stash apply             # Apply without removing
git stash drop              # Remove latest stash

# Interactive rebase
git rebase -i HEAD~3
# Commands: pick, reword, edit, squash, fixup, drop

# Bisect (find bug-introducing commit)
git bisect start
git bisect bad              # Current commit is bad
git bisect good <commit>   # Known good commit
# Git will checkout commits for you to test
git bisect reset            # When done

# Reflog (recover lost commits)
git reflog                  # Show all HEAD movements
git checkout HEAD@{2}       # Go to specific state

# Submodules
git submodule add <url> <path>
git submodule update --init --recursive

# Worktrees (multiple working directories)
git worktree add ../feature-branch feature-branch
git worktree list
git worktree remove ../feature-branch

# Aliases
git config --global alias.co checkout
git config --global alias.br branch
git config --global alias.st status
git config --global alias.lg "log --oneline --graph"