#!/usr/bin/env bash

cd "${0%/*}"
unset __NO_SUCH_VAR
POPULATED="words" EMPTY="" ../mo --fail-not-set 2>&1 <<EOF
Populated: {{POPULATED}};
Empty: {{EMPTY}};
Unset: {{__NO_SUCH_VAR}};
EOF

if [[ $? -ne 1 ]]; then
    echo "Did not return 1"
fi