Ruby on rails 既然Rails 5.1不支持'xhr'和'xml_http_请求'，如何配置和测试外部JS请求？

我正在测试一个控制器动作，该动作响应可嵌入外部站点的脚本

xhr :get, :index, params: { format: :js }

Rails已开始引发以下注意事项

DEPRECATION WARNING: `xhr` and `xml_http_request` are deprecated and will be removed in Rails 5.1.
Switch to e.g. `post :create, params: { comment: { body: 'Honey bunny' } }, xhr: true`.

如果我按照这些建议修改控制器规范

get :index, params: { format: :js }, xhr: true

我得到以下错误

ActionController::InvalidCrossOriginRequest:
        Security warning: an embedded <script> tag on another site requested protected JavaScript. If you know what you're doing, go ahead and disable forgery protection on this action to permit cross-origin JavaScript embedding.

如果是这样，那么前面的

xhr:get

语法是如何启用请求以避免跨源错误的

# my_embeddable_controller.rb
protect_from_forgery except: :index