function isMember(req, res, next) {
MyService.GetUserAsync(authCookie)
        .then(function (user) {
            next();
        })
        .catch(function (err) {
            if (err.status === 400) {
                return res.redirect("/notAllowed");
            }
            else {
                return next(err);
            }
        });
}

beforeEach(function () {
            // Overwrite the global timer functions (setTimeout, setInterval) with Sinon fakes
            this.clock = sinon.useFakeTimers();
        });
        afterEach(function () {
            // Restore the global timer functions to their native implementations
            this.clock.restore();
        });

 it.only("pass authentication and set authCookie", function (done) {
            var user = {
                userNameField: "fakeUserName"
            };
            sinon.stub(MyService, "GetUserAsync").returns(Promise.resolve(user));
            var spyCallback = sinon.spy();
            var req {};
            var res = {};
            isMember(req, res, spyCallback);
            // Not waiting here!
            this.clock.tick(1510);
            // spyCallback.called is always false
            expect(spyCallback.called).to.equal(true);
            done();
        });