? Git Hooks

? Quick Overview

Git hooks are scripts that Git executes before or after events such as commits, merges, and push actions. They help automate checks, enforce rules, and integrate workflows directly into the Git lifecycle.

? Key Concepts

Hooks are stored inside the .git/hooks directory
They run automatically on specific Git events
They can block actions if conditions fail
Written in shell, Bash, or any scripting language

? Syntax / Theory

Hooks are plain executable scripts. Git looks for a file with the hook name (without .sample) and executes it at the correct lifecycle stage.

? Code Examples

? View Code Example

# Run a linter before committing
#!/bin/sh
npm run lint

? View Code Example

# Make the pre-commit hook executable
chmod +x .git/hooks/pre-commit

? Live Output / Explanation

If the linter or test fails, Git cancels the commit or push. This ensures only validated code reaches the repository.

? Interactive Example

Try modifying your commit message format and observe how the commit-msg hook blocks invalid commits.

? View Code Example

# Validate commit message format
#!/bin/sh
commit_regex='^Issue #[0-9]+: .+'
if ! grep -qE "$commit_regex" "$1"; then
echo "Invalid commit message"
exit 1
fi

? Use Cases

Running tests before commits
Enforcing commit message standards
Preventing broken code from being pushed
Triggering notifications or scripts

? Tips & Best Practices

Keep hooks fast to avoid slowing developers
Test hooks locally before team adoption
Use tools like Husky for easier management

? Try It Yourself

Create a pre-commit hook to run tests
Add a commit-msg hook for format checks
Experiment with pre-push validation