expectAsync extension for jasmine

expectAsync.js

    var CALL_TIMEOUT = 4000;

    function expectAsync(promise, expectations) {
        var completed = false;
        runs(function () {
            promise.call().always(function () {
                completed = true;
            })
        });

        waitsFor(function () {
            return completed;
        }, CALL_TIMEOUT);

        runs(function () {
            expectations.call();
        });
    }

it("server connection should be invalid", function () {
    expectAsync(function () {
        return client.discover();
    }, function () {
        expect(client.hasValidSession()).toBeFalsy();
    });
});