jasmine mock window object

Question

How do I mock window object? I'm doing firefox extension and I want to use jasmine for javascript testing.

In my javascript I have

function submit() {
...
var url = window.arguments[0];
...
}

Obviously, I have to mock window.arguments[0] in jasmine because that object doesn't exists if not passing any parameter from window.openDialog

This is my attempt to mock it with "with"

it("should submit to server", function() {

        var localContext = {
            "window": {
                arguments: ["http://localhost"]
            }

        }

        with(localContext);

But I still get this error TypeError: Cannot read property '0' of undefined, it's like when the test is run window.arguments[0] gets wiped out with the real window, because if I do

window.arguments[0]

inside the test, it prints out "http://localhost" correctly. but when it comes to submit() method it shows the error that window.argument is undefined.