Engineering Craft › Version Control (Git)

Git Hooks

Scripts that run on Git events, like linting before a commit.

Also known as: pre-commit hook, githooks

Git hooks are scripts that Git runs at certain points, such as before a commit is created (pre-commit) or before a push (pre-push). A hook that exits with a non-zero status stops the action, which lets you enforce checks like linting or tests before the change is recorded.

Hooks live in .git/hooks inside each clone. A pre-commit hook that exits with a non-zero status blocks the commit.

#!/bin/sh
# .git/hooks/pre-commit
echo "pre-commit ran"
exit 1                     # non-zero: the commit is rejected

The catch is that .git/hooks isn’t part of the repository, so a fresh clone doesn’t get your hooks. Teams often keep hook scripts in the repo and point Git at them with the core.hooksPath setting. Behaviour differs a little with that setting, so check your Git version’s documentation.

The trade-off is enforcement against speed and friction. A slow hook makes every commit feel sluggish, and people bypass hooks with --no-verify when they’re annoyed. A hook is a local convenience, not a guarantee, because anyone can skip it.

The classic mistake is relying on a local hook as the only check. Run the same tests and linting in your CI pipeline, where every change is checked the same way. Use hooks to catch problems early, and keep them fast enough that people leave them on.