#!/bin/bash -e

function run_test {
    if git rev-parse --verify HEAD >/dev/null 2>&1 ; then
        head="HEAD"
    else
        # First commit, use an empty tree
        head="4b825dc642cb6eb9a060e54bf8d69288fbee4904"
    fi
    git diff-index --check --cached "${head}" --
}

case "${1}" in
    --about )
        echo "Check for introduced trailing whitespace or an indent that uses a space before a tab."
        ;;
    * )
        run_test
        ;;
esac