class Spec::Rails::Matchers::RedirectTo

def expected_url
   case @expected
     when Hash
       return ActionController::UrlRewriter.new(@request, {}).rewrite(@expected)
     when :back
       return @request.env['HTTP_REFERER']
     when %r{^\w+://.*}
       return @expected
     else
       return "http://#{@request.host}" + (@expected.split('')[0] == '/' ? '' : '/') + @expected
   end
 end