getter for httpServer internal

[Mathsfly]

• I've searched for any related issues and avoided creating a duplicate issue.

Description

There isn't 'close' event for server, it may be useful the 'listening' event and 'close' event of httpServer. I think we should make a httpServer getter of Server that is actually private.

[lpinca]

Adding a getter for the private http server is like making it public. I don't think it makes sense.
We can forward the 'close' event to the WebSocketServer but it's already possible to use that event by using an external http server.

const server = http.createServer();

const wss = new WebSocket.Server({ server });

server.on('close', function () {
  // ...
});
server.listen();

[Mathsfly]

The purpose is to make the 'close' event to be official that we can use it in both case.
`// Create internally, listening automatically
const wss = new WebSocket.Server({ port: 3333 });
//does
wss.on('listening', function () {
// ...
});
//behavior given
wss.close(callback)

// behavior expected
wss.on('close', () => {})
wss.close()`

[lpinca]

The problem is that our listeners are removed when WebSocketServer.prototype.close() is called so we can't currently reemit the 'close' event.

We can remove the listeners after the 'close' event is emitted but I'm not sure if it has side effects.

[izelnakri]

Is there any way to listen to WebSocketServer close currently?

[lpinca]

@izelnakri no, there is only the callback which is called when the 'close' event is emitted.

[izelnakri]

wss.on('close', () => console.log('called!')); 

wss.close();

this isnt working, would be nice if we clean up the listeners after the close event.

[lpinca]

There is no 'close' event on WebSocketServer only on the internal HTTP server.

wss.close(function () {
  // Clear listeners.
});