Check to see if WebSocket is hixie client-side?

Question

According to the WebSocket W3C draft in 2009 the CLOSED constant has a value of 2:

[Constructor(in DOMString url, in optional DOMString protocol)]
interface WebSocket {
  ...
  // ready state
  const unsigned short CONNECTING = 0;
  const unsigned short OPEN = 1;
  const unsigned short CLOSED = 2;
  ...
};
WebSocket implements EventTarget;

In the W3C draft dated in 2011 CLOSED has a value of 3:

[Constructor(in DOMString url, in optional DOMString protocols)]
[Constructor(in DOMString url, in optional DOMString[] protocols)]
interface WebSocket {
  ...
  // ready state
  const unsigned short CONNECTING = 0;
  const unsigned short OPEN = 1;
  const unsigned short CLOSING = 2;
  const unsigned short CLOSED = 3;
  ...
};

The 2009 draft corresponds to hixie/hibi-00 whereas the 2011 draft corresponds with hibi-07 and later, as seen on the Wikipedia chart.

With this information you can do a JavaScript check like this:

if("WebSocket" in window && WebSocket.CLOSED > 2) {
    // hibi-07 to RFC6455
} else {
    // No WebSocket, or hixie
}

I've used the following test page on a browser screen shot service:

<html>
<body>
<div id="test"></div>
<script>
var test = document.getElementById("test");
var text = "no soup for you!";
if ("WebSocket" in window) {
    text = "WebSocket " + WebSocket.CLOSED;
} else if("MozWebSocket" in window) {
    text = "MozWebSocket " + MozWebSocket.CLOSED;
}
test.appendChild(document.createTextNode(text));
</script>
</body>
</html>

Safari 5 and Chrome 12 and below return 2, whereas Safari 6 and Chrome 14 and above returns 3 for CLOSED.

Chrome 13 uses uses hixie, but returns 3. This is the only edge case I could find. Since Chrome auto-updates, Chrome 13 users should be zero.

NOTE: These constants are set on both the WebSocket constructor and WebSocket.prototype. Safari 5.0, prior to 5.1, only sets these constants on WebSocket.prototype. If you only plan to support RFC6455 and above, WebSocket.CLOSED > 2 or WebSocket.CLOSED === 3 is sufficient.