[[ ${TESTS_COMMON_SOURCED:-} -eq 1 ]] && return || readonly TESTS_COMMON_SOURCED=1

declare -a cnt
cnt=(0 0)
function inc_testno { cnt[0]=$((cnt[0] + 1)); }
function inc_errors { cnt[1]=$((cnt[1] + 1)); }
function test_name { echo "test_${cnt[0]}"; }
ts=$(date +%s%N)
function print_info {
  tt=$((($(date +%s%N) - $ts)/1000000))
  echo "----------------------------------------------------------------------"
  echo -n "Ran ${cnt[0]} tests in "
  echo -n $tt | awk '{ printf("%d.%03d", int($1/1000), int($1%1000)); }'
  echo -e "s\n"
  if (( cnt[1] == 0 )); then
    echo OK
    exit 0
  else
    echo "FAILED (failures=${cnt[1]})"
    exit ${cnt[1]}
  fi
}
function test_result {
  inc_testno
  echo -n "$(test_name): "
  if [[ $1 = "0" ]]; then
    echo -n "OK  "
  else
    echo -n "FAIL"
    inc_errors
  fi
  echo " ${@:2}"
}