assert_redirected_to

# File actionpack/lib/action_controller/assertions/response_assertions.rb, line 59
      def assert_redirected_to(options = {}, message=nil)
        clean_backtrace do
          assert_response(:redirect, message)
          return true if options == @response.redirected_to
          ActionController::Routing::Routes.reload if ActionController::Routing::Routes.empty?

          begin
            url  = {}
            original = { :expected => options, :actual => @response.redirected_to.is_a?(Symbol) ? @response.redirected_to : @response.redirected_to.dup }
            original.each do |key, value|
              if value.is_a?(Symbol)
                value = @controller.respond_to?(value, true) ? @controller.send(value) : @controller.send("hash_for_#{value}_url")
              end

              unless value.is_a?(Hash)
                request = case value
                  when NilClass    then nil
                  when /^\w+:\/\// then recognized_request_for(%r{^(\w+://.*?(/|$|\?))(.*)$} =~ value ? $3 : nil)
                  else                  recognized_request_for(value)
                end
                value = request.path_parameters if request
              end

              if value.is_a?(Hash) # stringify 2 levels of hash keys
                if name = value.delete(:use_route)
                  route = ActionController::Routing::Routes.named_routes[name]
                  value.update(route.parameter_shell)
                end

                value.stringify_keys!
                value.values.select { |v| v.is_a?(Hash) }.collect { |v| v.stringify_keys! }
                if key == :expected && value['controller'] == @controller.controller_name && original[:actual].is_a?(Hash)
                  original[:actual].stringify_keys!
                  value.delete('controller') if original[:actual]['controller'].nil? || original[:actual]['controller'] == value['controller']
                end
              end

              if value.respond_to?(:[]) && value['controller']
                value['controller'] = value['controller'].to_s
                if key == :actual && value['controller'].first != '/' && !value['controller'].include?('/')
                  new_controller_path = ActionController::Routing.controller_relative_to(value['controller'], @controller.class.controller_path)
                  value['controller'] = new_controller_path if value['controller'] != new_controller_path && ActionController::Routing.possible_controllers.include?(new_controller_path)
                end
                value['controller'] = value['controller'][1..-1] if value['controller'].first == '/' # strip leading hash
              end
              url[key] = value
            end

            @response_diff = url[:actual].diff(url[:expected]) if url[:actual]
            msg = build_message(message, "expected a redirect to <?>, found one to <?>, a difference of <?> ", url[:expected], url[:actual], @response_diff)

            assert_block(msg) do
              url[:expected].keys.all? do |k|
                if k == :controller then url[:expected][k] == ActionController::Routing.controller_relative_to(url[:actual][k], @controller.class.controller_path)
                else parameterize(url[:expected][k]) == parameterize(url[:actual][k])
                end
              end
            end
          rescue ActionController::RoutingError # routing failed us, so match the strings only.
            msg = build_message(message, "expected a redirect to <?>, found one to <?>", options, @response.redirect_url)
            url_regexp = %r{^(\w+://.*?(/|$|\?))(.*)$}
            eurl, epath, url, path = [options, @response.redirect_url].collect do |url|
              u, p = (url_regexp =~ url) ? [$1, $3] : [nil, url]
              [u, (p.first == '/') ? p : '/' + p]
            end.flatten

            assert_equal(eurl, url, msg) if eurl && url
            assert_equal(epath, path, msg) if epath && path
          end
        end
      end