--- /Users/cturner/Desktop/run_script.rb
+++ run_script.rb
@@ -62,7 +62,7 @@
       htmlize(str).gsub(/[EF]+/, "<span style=\"color: red\">\\&</span>") +
             "<br style=\"display: none\"/>"
     elsif is_test_script
-      out = str.map do |line|
+      out = str.send(str.respond_to?(:lines) ? :lines : :to_s).map do |line|
         if line =~ /^(\s+)(\S.*?):(\d+)(?::in\s*`(.*?)')?/
           indent, file, line, method = $1, $2, $3, $4
           url, display_name = '', 'untitled document';