diff --git a/test/poc.test.bash b/test/poc.test.bash
new file mode 100755
index 0000000..b5e4488
--- /dev/null
+++ b/test/poc.test.bash
@@ -0,0 +1,81 @@
+#!/usr/bin/env bash
+
+# CONSTANTS
+
+TEST_COUNT=0
+SUCCESS_COUNT=0
+# functions
+
+function assert {
+  ((TEST_COUNT++))
+  if ./poc ./test/stub/scenario.bash "$1" >/dev/null; then
+    echo -n .
+    ((SUCCESS_COUNT++))
+  else
+    (echo "error in: $1" && exit 1)
+  fi
+
+}
+
+function fail_type {
+  ((TEST_COUNT++))
+  local i line first error_start_above regex hint_message
+  hint_message="${3:-}"
+  mapfile -t stderr <<<"$(./test/stub/scenario.bash "$1" 2>&1 >/dev/null)"
+  # echo "stderr countains ${#stderr[@]}"
+  error_start_above=false
+  success=false
+  regex="║[[:blank:]]+([A-Z|_]+)"
+  for i in "${!stderr[@]}"; do
+    line=$(strip_ansi "${stderr[$i]}")
+    first="${line:1:1}"
+    [[ $first == ╔ ]] && error_start_above=true && continue
+    if [[ "$error_start_above" == true ]]; then
+      [[ $line =~ $regex ]] && [[ ${BASH_REMATCH[1]} == "$2" ]] && success=true
+      break
+    fi
+  done
+
+  if [[ $success == true && -n "${hint_message}" ]]; then
+    success=false
+    regex="╟─⟶.*(\(.*\))$"
+    for j in $(seq "$((i + 1))" "$((${#stderr[@]} - 1))"); do
+      line=$(strip_ansi "${stderr[$j]}")
+      if [[ $line =~ $regex ]]; then
+        [[ "${BASH_REMATCH[1]}" == "${hint_message}" ]] && success=true
+        break
+      fi
+    done
+  fi
+  if [[ $success == true ]]; then
+    ((SUCCESS_COUNT++))
+  else
+    echo "error in: $1" && return 1
+  fi
+}
+
+# main
+set -uo pipefail
+
+assert success
+# fail_type subshell_term SUBSHELL_TERM
+# fail_type unbound_variable UNBOUND_VARIABLE
+# fail_type false FALSE
+# fail_type return RETURN
+# fail_type command_not_found COMMAND_NOT_FOUND
+# fail_type exit EXIT
+# fail_type source_not_found SOURCE_NOT_FOUND
+# fail_type file_not_found FILE_NOT_FOUND
+# fail_type subshell_error COMMAND_NOT_FOUND '(hint: prefer source than subshell)'
+# fail_type command_error COMMAND_ERROR
+
+failed=$((TEST_COUNT - SUCCESS_COUNT))
+
+echo
+if [[ $failed -gt 0 ]]; then
+  ratio=$((100 * SUCCESS_COUNT / TEST_COUNT))
+  echo "${ratio}% passed, $SUCCESS_COUNT succeeded, $failed failed!"
+  exit 1
+else
+  echo 100% passed!
+fi