Automating Quality Gates with Git Hooks

What Are Git Hooks?

Git hooks are shell scripts that Git executes automatically at specific points in the workflow — before a commit, after a push, before a rebase, and more. They live in .git/hooks/ and run locally on every developer's machine.

Most Useful Hooks

• pre-commit — runs before the commit message editor opens. Ideal for linting and formatting checks.
• commit-msg — receives the commit message file path. Use it to enforce message conventions.
• pre-push — runs before git push. Great for running the test suite to block broken pushes.
• post-merge — runs after a successful merge. Common use: npm install when package.json changed.

Writing a pre-commit Hook

# .git/hooks/pre-commit  (must be executable: chmod +x .git/hooks/pre-commit)
#!/usr/bin/env bash
set -e
echo "Running ESLint..."
npx eslint --max-warnings=0 src/
echo "Running type-check..."
npx tsc --noEmit

If the script exits with a non-zero code, Git aborts the commit. The developer sees the error output and must fix it before committing.

Sharing Hooks with the Team

Because .git/hooks/ is not committed to the repository, hooks are not automatically shared. Two popular solutions:

• Husky (npm install --save-dev husky) — stores hooks in .husky/ (which IS committed) and registers them via a prepare script.
• `core.hooksPath` — point Git to a committed directory: git config core.hooksPath .githooks.