public/chats.html

<!doctype html>
<html>
<head>
  <title>Socket.IO chat</title>
  <style>
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }

    body {
      font: 13px Helvetica, Arial;
    }

    form {
      background: #000;
      padding: 3px;
      position: fixed;
      bottom: 0;
      width: 100%;
    }

    form input {
      border: 0;
      padding: 10px;
      width: 90%;
      margin-right: .5%;
    }

    form button {
      width: 9%;
      background: rgb(130, 224, 255);
      border: none;
      padding: 10px;
    }

    #messages {
      list-style-type: none;
      margin: 0;
      padding: 0;
    }

    #messages li {
      padding: 5px 10px;
    }

    #messages li:nth-child(odd) {
      background: #eee;
    }

    #messages {
      margin-bottom: 40px
    }
  </style>
</head>
<body>
<ul id="messages"></ul>
<form action="">
  <input id="m" autocomplete="off"/>
  <button>Send</button>
</form>
<button id="emitRoomEvent">Emit room event</button>
<script src="https://cdnjs.cloudflare.com/ajax/libs/socket.io/2.1.1/socket.io.js"></script>
<script src="https://code.jquery.com/jquery-1.11.1.js"></script>
<script>
  $(function () {
    var socket = io('/chats/1');
    $('form').submit(function () {
      socket.emit('chat message', $('#m').val());
      $('#m').val('');
      return false;
    });
    socket.on('chat message', function (msg) {
      $('#messages').append($('<li>').text(msg));
      window.scrollTo(0, document.body.scrollHeight);
    });
    socket.on('some room event', function (msg) {
      console.log('msg', msg)
      $('#messages').append($('<li>').text(`some room event: ${msg}`));
      window.scrollTo(0, document.body.scrollHeight);
    });
    $('#emitRoomEvent').on('click', function () {
      $.post('/todos/room/example/emit')
        .then(console.log);
    });
  });
</script>
</body>
</html>