public async Task FetchBirthdays() { var birthdayViewModel = new BirthdaysViewModel(new BirthdayServiceFake()); using (var propertyChangedTracker = new PropertyChangeTracker(birthdayViewModel)) { await birthdayViewModel.FetchBirthdays(); Assert.NotNull(birthdayViewModel.ClosestBirthDay); Assert.True(birthdayViewModel.FutureBirthdays.Count > 0); propertyChangedTracker.VerifyNumberOfNotifications(2); propertyChangedTracker.VerifyNotificationOfName("ClosestBirthDay"); propertyChangedTracker.VerifyNotificationOfName("FutureBirthdays"); } }