GitLab pre-receive hook

#!/bin/bash

#https://git-scm.com/docs/githooks#pre-receive

set -Eeuo pipefail

TALISMANRC=".talismanrc"

fail() {
  echo "$1"
  exit 1
}

ensure_program() {
  which $1 || fail "$1 not available"
}

ensure_programs() {
  ensure_program talisman
  ensure_program git
}

get_changed_content_and_scan() {
  CUR_DIR=$(pwd)
  TEMP_DIR=$(mktemp -d)

  cd "${TEMP_DIR}"
  git init
  cd "${CUR_DIR}"

  while read OLDREV NEWREV REFNAME; do
    if [ "${OLDREV}" = "0000000000000000000000000000000000000000" ]; then
      OLDREV="${NEWREV}"
    fi

    FILES=$(git diff --name-only ${OLDREV} ${NEWREV})
    if [ -n "${FILES}" ]; then
      for FILE in ${FILES}; do
        mkdir -p "${TEMP_DIR}/$(dirname ${FILE})" &>/dev/null
        git show ${NEWREV}:${FILE} > "${TEMP_DIR}/${FILE}"
      done

      cd "${TEMP_DIR}"
      git add .
      git commit -m "temp: ${REFNAME}"

      if [ -n "$(git ls-files ${NEWREV}:.talismanrc)" ]; then
        git show "${NEWREV}:${TALISMANRC}" > "${TEMP_DIR}/${TALISMANRC}"
      fi
      cd "${CUR_DIR}"
    fi
  done

  cd "${TEMP_DIR}"

  REPORTS_DIR="${TEMP_DIR}/talisman_reports"

  mkdir -p "${REPORTS_DIR}"
  talisman --scan --reportdirectory "${REPORTS_DIR}"
  CHECK_RESULT=$?

  if [ ${CHECK_RESULT} -ne 0 ]; then
    cat "${REPORTS_DIR}/*"
  fi

  echo "TODO: We should run rm -rf \"${TEMP_DIR}\" now, but we don't just for testing."
  exit ${CHECK_RESULT}
}

main() {
  ensure_programs
  get_changed_content_and_scan
}

main "$@"