output debug for failed parses

test/parser/helper.rb

@@ -1,5 +1,5 @@
 require_relative "../helper"
-
+require "parslet/convenience"
 # Included in parser test will create tests methods
 module ParserHelper
   
@@ -16,7 +16,7 @@ module ParserHelper
 
     # check that @string_input parses correctly to @parse_output
     def check_parse
-      is = @parser.parse(@string_input)
+      is = @parser.parse_with_debug(@string_input)
       #puts is.inspect
       assert_equal @parse_output , is
     end