determine_constant_from_test_name

# File activesupport/lib/active_support/testing/constant_lookup.rb, line 34
        def determine_constant_from_test_name(test_name)
          names = test_name.split "::"
          while names.size > 0 do
            names.last.sub!(/Test$/, "")
            begin
              constant = names.join("::").constantize
              break(constant) if yield(constant)
            rescue NoMethodError # subclass of NameError
              raise
            rescue NameError
              # Constant wasn't found, move on
            ensure
              names.pop
            end
          end
        end