WebSocketIRIS.js

 This is a coding example working on IRIS 2020.1  
 It will not be kept in sync with new versions      
 It is also NOT serviced by InterSystems Support !   

This is now the version compatible to IRIS using IRIS Native API for Node.js
which is significantly different from the interface availaible for Caché.

Node / JavaScript have wide reputation to work as WebSocket client.
By using the IRIS adapter it becomes easy to control and to consume the results as a
Client for WebSocket Servers and to collect the replies in IRIS.

I used node-v10.15.1-x64.msi and intersystems-iris-native package

You provide a Global for input:

 ^WsockIn="wss://echo.websocket.org/"
 ^WsockIn(0)=6
 ^WsockIn(1)="Hello"
 ^WsockIn(2)="World !"
 ^WsockIn(3)="Robert"
 ^WsockIn(4)="is waiting"
 ^WsockIn(5)="for replies"
 ^WsockIn(6)="exit"

and from echo server you get back a Global as output
written by Node.js using the Native API for Node.js

 ^WsockOut(0)=6
 ^WsockOut(1)="Hello"
 ^WsockOut(2)="World !"
 ^WsockOut(3)="Robert"
 ^WsockOut(4)="is waiting"
 ^WsockOut(5)="for replies"
 ^WsockOut(6)="exit"

the server is controlled by ^ZSocketRun from IRIS

-1 => stop server and exit  
 0 => wait for action  
 1 => sent to echo server  
 ^ZSocketRun(0)= echo server => "wss://echo.websocket.org/"  

The WebSocket Service is started from OS command line.
You can follow the progress in console output

  C:\Program Files\nodejs\cache>node WebSocketIRIS.js

    *****************************
    *** no IRIS host defined ****
    Connect to IRIS on: localhost
Successfully connected to InterSystems IRIS.
    echoserver:  wss://echo.websocket.org/
    ** Lines to process: 6 **
    ********* next turn *********
    ******* Startup done ********

    * WebSocket Client connected *
    ****** Client is ready ******
Line: 1 text> 'Hello'
Received: 1 > 'Hello'
Line: 2 text> 'World !'
Received: 2 > 'World !'
Line: 3 text> 'Robert'
Received: 3 > 'Robert'
Line: 4 text> 'is waiting'
Received: 4 > 'is waiting'
Line: 5 text> 'for replies'
Received: 5 > 'for replies'
    *** wait 3sec for request ***
Line: 6 text> 'exit'
Received: 6 > 'exit'

    ******* lines sent: 6 ******
    *** replies received: 6 ****

    *** wait 3sec for request ***
    *** wait 3sec for request ***
    *** wait 3sec for request ***
    *** wait 3sec for request ***
    *** wait 3sec for request ***
    *** wait 3sec for request ***
    *** Client Service closed ***