So I am kinda losing my head rn, since I just can't find a way of broadcasting/sending a msg to all other clients whenever someone disconnects.

Any help would be appreciated.

var socket = new WebSocket( "ws://localhost:8080" );
    socket.onopen = ( e ) => {
        socket.send( JSON.stringify({ "userconnection": true }) );
    }
    socket.onmessage = ( e ) => {
        console.log( e.data );
    }
    socket.onclose = ( e ) => {
        socket.send( JSON.stringify({ "userdisconnect": true }) );
    }

As I read it in socket.io it is possible to emit a message on connect and disconnect is it possible with WebSocket API js