Pre Commit hook, proper stashing with unstash using bash traps (in case of errors halfway)

pre-commit.sh

#!/bin/bash
#
# An example hook script to verify what is about to be committed.
# Called by "git commit" with no arguments.  The hook should
# exit with non-zero status after issuing an appropriate message if
# it wants to stop the commit.

git stash -u --keep-index
trap "git stash pop --quiet --index; exit 1" SIGINT SIGTERM

# your checks, only working on staged changes

git stash pop --quiet