testing via handlers

[pedz]

I think this pattern is going to grow over time given that the browser
GUI is single threaded. More and more I am going to a pattern where I
fire a start action and then wait for a completion event. In today's
example, I'm firing a request to a web worker which return a result
asynchronously via one of a few handlers -- onComplete, onError, etc.

I'm going to start trying to figure out a way to do this but what I
believe I want is something like:

it('should alert when worker is not found', function() {
loader = Loader({ worker_path: "bogus", onComplete:
onCompleteHandler });
loader.load_file("abcd");
wait_until([ onCompleteHandler, alert ], 6);
var z = get_alert_text();
z.length.should.eql(1);
});

Where wait_until waits for up to 6 seconds in this example or until
one of the two functions is called.

The array of handlers could be omitted and use the proxy facilities.
The array would just be a shorthand method.

If anyone has some suggestions that will help me with this, that would
be great to hear.

Thank you
Perry