def require_signin
    if !signed_in?  
      flash.now.alert = "Log in first!"
      redirect_to signin_path
    end
  end

这是rspec代码：

it "should invoke require_signin for those without login" do
  controller.send(:require_signin)
  controller {should redirect_to signin_path}  
end

以上rspec生成巨大的多页错误,如下所示：

RuntimeError:←[0m
       ←[31mActionController::RackDelegation#status= delegated to @_response.status=,but @_response is nil: #<ApplicationController:0x3
a67f10 @_routes=nil,@_action_has_layout=true,@_view_context_class=nil,@_headers={"Content-Type"=>"text/html"},@_status=200,@_reques
t=#<ActionController::TestRequest:0x3a68720 @env={"rack.version"=>[1,1],"rack.input"=>#<StringIO:0x34fad60>,........

rspec代码有什么问题？非常感谢.