test/e2e/resources/network/websocket.html

<!DOCTYPE html>
<body>
  <script>
    function shouldSendInfiniteMessages() {
      const url = new URL(document.location);
      return !!url.searchParams.get('infiniteMessages');
    }

    const protocol = location.protocol.replace('http', 'ws');
    const url = protocol + '//' + location.host + '/'
    const ws = new WebSocket(url);
    ws.onopen = () => {
      if (shouldSendInfiniteMessages()) {
        setInterval(() => {
          ws.send('ping');
        }, 100);
      } else {
        ws.send('ping');
      }
    }

    ws.onmessage = (msg) => {
      if (msg.data == 'ping') ws.send('pong')
    };
  </script>
</body>