Git hook to add ticket number to commit message

prepare-commit-msg

#!/bin/bash
#
# This hook adds issue/ticket number from branch name to every commit message
#

BRANCH_NAME=$(git symbolic-ref --short HEAD)
MSG=$(head -n 1 "${1}")

[[ -z "${BRANCH_NAME}" ]] && exit 0

TICKET=$(echo "${BRANCH_NAME}" | grep -m 1 -oE "^v?[0-9\.]+|^\w+-[0-9]+" | head -n1)
if [[ "${TICKET}" == "" ]]; then
  PREPEND="[${BRANCH_NAME}] "
elif [[ "${TICKET}" =~ ^[0-9]+$ ]]; then
  PREPEND="#${TICKET} "
else
  PREPEND="[${TICKET}] "
fi

[[ "${MSG:0:${#PREPEND}}" == "${PREPEND}" ]] && exit 0

sed -i.bak -e "1s|^|${PREPEND}|" "${1}"