My commit-msg hook

commit-msg

#!/usr/bin/env bash

readonly MAX_SUBJ_LINE_LEN=75
readonly MAX_BODY_LINE_LEN=72

read -r subject < "$1"

if [[ "${subject}" =~ ^Revert ]]; then
    # Skip checking commit message generated by git-revert(1)
    exit 0

else
    # Verify Conventional Commits Specification compliance
    [[ "${subject}" =~ ^(ci|rm|fix|feat|docs|test|perf|build|chore|style|refactor)\(?.*\)?:' '.+$ ]] || {

        echo 'Bad message subject' >&2

        exit 1
    }

    (( "${#subject}" > MAX_SUBJ_LINE_LEN )) && {

        echo "Message subject exceeds ${MAX_SUBJ_LINE_LEN} characters" >&2

        exit 1
    }

fi

l=1

while read -r line; do

    [[ "${line}" == "${subject}" ]] && {

        (( l++ ))
        continue
    }

    (( "${#line}" )) || {

        (( l++ ))
        continue
    }

    [[ "${line}" =~ ^# ]] && continue

    (( "${#line}" > MAX_BODY_LINE_LEN )) && {

        echo "Message line ${l} exceeds ${MAX_BODY_LINE_LEN} characters"

        exit 1
    }

done < "$1"

exit 0