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Manuals / Git & GitHub / Ch 10

D · AutomateAdvanced40 min read

10. Git hooks — pre-commit & pre-push

Git & GitHub · 48 pages source format

Hooks run scripts at Git lifecycle events. pre-commit: lint/format. pre-push: tests. Husky or plain .git/hooks.

What you'll learn

  • Hook scripts in .git/hooks
  • pre-commit framework
  • Husky for Node projects
  • CI vs local hooks

Simple pre-commit hook

Executable script in .git/hooks/pre-commit. Exit 1 blocks commit. Test in practice repo.

#!/bin/sh
# .git/hooks/pre-commit
if ! grep -q "." README.md 2>/dev/null; then
  echo "README must not be empty"
  exit 1
fi

Do this now

Hook that rejects commits if README is empty.

Clear?

pre-commit framework

pip install pre-commit. .pre-commit-config.yaml with ruff, trailing-whitespace. pre-commit install.

Do this now

Add pre-commit to py-journey or git-practice with trailing-whitespace hook.

Clear?

Husky for JS projects

npx husky init. pre-commit runs lint-staged. Complements CI — catches issues before push.

Do this now

If you have a JS project: add Husky pre-commit running npm test or lint.

Pro tip. Hooks are local — CI is the enforcement layer for teams. Both matter.

Clear?

Checklist