Fix nested describes in controller tests in Rails 2.3

fix_nested_describes_in_controller_tests.rb

# fixes nested describes in controller tests
# this is a Rails bug apparently fixed in newer Rails versions
# https://github.com/rails/rails/issues/7743
# This was originally written by @madrobby for Freckle: https://letsfreckle.com

class ActionController::TestCase
  def self.determine_default_controller_class(name)
    name.split('::').reverse.map { |n|
      safe_constantize(n.sub(/Test$/, ''))
    }.compact.first
  end
  private
    def self.safe_constantize(camel_cased_word)
      begin
        camel_cased_word.constantize
      rescue NameError => e
        raise unless e.message =~ /(uninitialized constant|wrong constant name) #{const_regexp(camel_cased_word)}$/ ||
          e.name.to_s == camel_cased_word.to_s
      rescue ArgumentError => e
        raise unless e.message =~ /not missing constant #{const_regexp(camel_cased_word)}\!$/
      end
    end
    def self.const_regexp(camel_cased_word) #:nodoc:
      parts = camel_cased_word.split("::")
      last  = parts.pop

      parts.reverse.inject(last) do |acc, part|
        part.empty? ? acc : "#{part}(::#{acc})?"
      end
    end
end