Safari extension: WebSocket onclose network connection failure, not onerror and exception

Question

I am writing browser extensions for Firefox, Chrome and Safari. When I try to connect to a WebSocket server using the Safari extension, where there is no server listening on a specific port, my Safari extension does not throw an exception and does not raise an onerror. Instead, the Safari onclose extension handler is called. I also see this message in the console:

[Error] WebSocket network error: The operation couldn’t be completed. Connection refused (global.html, line 0)

In Firefox and Chrome, it seems to handle AFAIK correctly and raise an onerror.

I'm just doing something like this:

var socket = new WebSocket('ws://127.0.0.1:'+inPort, inHandlerName);
socket.binaryType = "arraybuffer";

then declare handlers for onopen, onclose, onerror and onmessage. inPort is 9000, and inHandlerName is a string of type "global-handler". I put exception handlers in each of the WebSocket handlers, as well as a function that has code that creates the WebSocket, but I don't see any exceptions.

Is this a known issue? Is there a way to find out if a connection has occurred?

Edit: This also happens on a simple web page in Safari:

        var theSocket = new WebSocket('ws://127.0.0.1:9000', 'global-message');

        theSocket.onopen = function()
        {
            console.log("onopen");
        };
        theSocket.onerror = function()
        {
            console.log("onerror");
        };
        theSocket.onmessage = function()
        {
            console.log("onmessage");
        };
        theSocket.onclose = function()
        {
            console.log("onclose");
        };

Answer 1

This is not like how it should work, but in the onclose message I get this parameter:

theSocket.onclose = function(event)

, . , 1006. , , Safari, :

if(event.code == 1006)

, , Firefox Chrome.