restrict the root, but expand for testing

test/setup.rb

@@ -17,3 +17,10 @@ require 'salama-reader'
 
 require "minitest"
 require "minitest/autorun"
+
+# for testing add expression as allowed root
+# bit of a hack: the directory name should be passed as the root if the parse fails
+# but moving on (and coming back)
+Parser::Salama.class_eval do
+  rule(:root_body)    {( class_definition | function_definition | expression  )}
+end