git clone -b websocket https://github.com/guzhongren/FrontEndStudy.git
$ cd FrontEndStudy
$ npm install
# yarn
$ npm run server
# yarn run server
$ npm run browser
# yarn run browser
http://127.0.0.1:40765/view/
http://127.0.0.1:40765/test/websocket.html # 看控制台信息