Git Basics for Rails Developers

Introduction

This guide covers essential Git commands and workflows you’ll use daily as a Rails developer, plus some helpful advanced commands for specific situations.

Daily Git Commands

Starting Your Day

# Update your main branch
git checkout main
git pull origin main

# Create a new branch for your work
git checkout -b feature/add-user-authentication

# Check branch status
git status

Working with Changes

# Stage specific files
git add app/models/user.rb
git add app/controllers/users_controller.rb

# Stage all changes
git add .

# Stage parts of files
git add -p

# See what's staged
git diff --staged

# See unstaged changes
git diff

# Commit changes
git commit -m "Add User model and controller"

# Amend last commit (before pushing)
git commit --amend

Pushing and Pulling

# Push your branch
git push origin feature/add-user-authentication

# Pull latest changes from main
git pull origin main

# Pull with rebase
git pull --rebase origin main

Common Scenarios

Fixing Mistakes

# Undo staged changes
git reset HEAD app/models/user.rb

# Discard local changes
git checkout -- app/models/user.rb

# Undo last commit (keeping changes staged)
git reset --soft HEAD^

# Undo last commit (discarding changes)
git reset --hard HEAD^

# Remove untracked files
git clean -fd

Working with Branches

# List all branches
git branch

# Switch to existing branch
git checkout other-branch

# Delete local branch
git branch -d feature/old-feature

# Delete remote branch
git push origin --delete feature/old-feature

# Rename current branch
git branch -m new-branch-name

Stashing Changes

# Basic stash
git stash

# Stash with message
git stash save "WIP: User authentication"

# List stashes
git stash list

# Apply most recent stash
git stash pop

# Apply specific stash
git stash apply stash@{2}

# Drop specific stash
git stash drop stash@{0}

# Clear all stashes
git stash clear

Rails-Specific Scenarios

Handling Database Changes

# Stash everything including untracked files
git stash -u

# Pull latest changes
git pull origin main

# Apply stash and run migrations
git stash pop && rails db:migrate

Managing Credentials

# Check if credentials are tracked
git check-ignore config/credentials.yml.enc
git check-ignore config/master.key

# Remove tracked credentials (if accidentally committed)
git rm --cached config/master.key

Advanced Git Commands

Searching and History

# Search commit messages
git log --grep="authentication"

# Search for code changes
git log -S"def authenticate_user"

# Show file history
git log --follow -p app/models/user.rb

# Show who changed each line
git blame app/models/user.rb

# Find which commit introduced a bug
git bisect start
git bisect bad  # Current commit is broken
git bisect good v1.0.0  # This version worked
# Git will help you find the problematic commit

Cleaning and Maintenance

# Remove old branches that were merged
git branch --merged | grep -v "\*" | xargs -n 1 git branch -d

# Clean up remote-tracking branches
git remote prune origin

# Compress repository
git gc

# Verify repository integrity
git fsck

Advanced Rebase Operations

# Interactive rebase last 3 commits
git rebase -i HEAD~3

# Squash commits during rebase
# In the interactive rebase editor:
pick f7f3f6d First commit
squash 310154e Second commit
squash a5f4a0d Third commit

# Fixup commit (like squash but discard commit message)
git commit --fixup f7f3f6d
git rebase -i --autosquash HEAD~3

Git Configuration Tips

Essential Configuration

# Set your identity
git config --global user.name "Your Name"
git config --global user.email "your.email@example.com"

# Set default branch name
git config --global init.defaultBranch main

# Set default editor
git config --global core.editor "code --wait"

# Enable color output
git config --global color.ui true

Helpful Aliases

# Add these to your ~/.gitconfig
[alias]
    # Quick status
    st = status -sb

    # Better log
    lg = log --graph --pretty=format:'%Cred%h%Creset -%C(yellow)%d%Creset %s %Cgreen(%cr) %C(bold blue)<%an>%Creset' --abbrev-commit

    # Undo last commit
    undo = reset HEAD~1 --mixed

    # Show changes
    changes = diff --name-status

    # Amend without editing message
    amend = commit --amend --no-edit

Best Practices

Commit Messages

Use present tense ("Add feature" not "Added feature")
First line should be 50 characters or less
Follow with a blank line
Provide detailed explanation if needed

Example:

Add user authentication system

- Implement Devise for user management
- Add login/signup forms
- Configure user roles
- Add authentication tests

Branch Management

Keep branches focused and short-lived
Use descriptive branch names
Delete branches after merging
Regularly rebase feature branches on main

Pull Request Workflow

Create feature branch from main
Make small, focused commits
Keep branch up to date with main
Push branch and create PR
Address review comments
Merge or rebase when approved

Troubleshooting Common Issues

Merge Conflicts

# When conflict occurs
git status  # See conflicted files
git diff    # See conflicts in detail

# After resolving conflicts
git add .
git commit  # or git rebase --continue

# Abort merge if needed
git merge --abort

Reset Gone Wrong

# Find lost commits
git reflog

# Recover lost commit
git reset --hard HEAD@{1}

Additional Resources

Tip	Keep this guide handy for quick reference. Most developers, even experienced ones, regularly refer to Git documentation and guides.

Warning

Always be careful with destructive commands like git reset --hard and git clean -fd. They cannot be undone!