class ActionController::TestRequest

def assign_parameters(routes, controller_path, action, parameters = {})
  parameters = parameters.symbolize_keys.merge(:controller => controller_path, :action => action)
  extra_keys = routes.extra_keys(parameters)
  non_path_parameters = get? ? query_parameters : request_parameters
  parameters.each do |key, value|
    if value.is_a? Fixnum
      value = value.to_s
    elsif value.is_a? Array
      value = Result.new(value)
    end
    if extra_keys.include?(key.to_sym)
      non_path_parameters[key] = value
    else
      path_parameters[key.to_s] = value
    end
  end
  # Clear the combined params hash in case it was already referenced.
  @env.delete("action_dispatch.request.parameters")
  params = self.request_parameters.dup
  %w(controller action only_path).each do |k|
    params.delete(k)
    params.delete(k.to_sym)
  end
  data = params.to_query
  @env['CONTENT_LENGTH'] = data.length.to_s
  @env['rack.input'] = StringIO.new(data)
end