artcraft/static/websocket_test.js

(function() {
    console.log('installing script');

    const WS_URL = 'ws://localhost:54321/obs';

    let sock = new WebSocket(WS_URL);

    sock.onopen = function (event) {
        console.log('on open event', event);
        sock.send('on open message from client');
    };

    sock.onmessage = function (event) {
        console.log('on message event', event.data);
    }

    sock.send('this is a message from the client');
})();