plugin.install不是功能吗？

Question

我正在尝试使用Websocket将数据从node.js发送到Angular 7。 这就是我尝试过的：

'''NodeJs

  app.use(cors({
    origin:['ws://localhost:3535','ws://127.0.0.1:3535'],
    credentials:true
  }));


const wss = new WebSocket.Server({ port: 3535 })
wss.on('connection', ws => {
    ws.on('message', message => {
      console.log(`Received message => ${message}`)
    })
    ws.send('Hello! Message From Server!!')
  })

'''

'''角度

import * as socketIo from 'socket.io-client';


var socket = socketIo('http://localhost:3535');

....
export class MyAppComponent implements OnInit {



constructor() { }

ngOnInit() {

socket.onopen = () => {
  socket.send('Message From Client') 
}

socket.onerror = (error) => {
  console.log(`WebSocket error: ${error}`)
}

socket.onmessage = (e) => {
  console.log(e.data)
}


  }

'''

当我尝试运行后端时，尽管安装并导入它，但仍然出现cors访问问题，并且显示：

'''

Error -----------------------------------------------------------------

Message:
plugin.install is not a function

Stack:
TypeError: plugin.install is not a function
      at plugins.forEach                                                               

   ----------------------------------------------------------------------

'''