Node.js websocket, OnClose event doesn't fire, which lib should I use?

Question

Node.js

https://github.com/websockets/ws
Installed npm package.
The open and message events work fine.
When turning off the Internet, I waited about 5 minutes, but the OnClose event did not appear.
It became a reasonable question:
to make ping-pong commands that interrogate a web socket or change a lib or an interval of more than 5 minutes.

Answer 1

So it will be with any one, the normal closing of the socket is a special code (or an error code), when the connection is broken, there is no such code and you can find out that the connection is closed only when you try to send something to it, while ws normally throws an event