public void UpdateErrorsShouldNotifyListeners() { bool isAsync = false; ValidatorBase validator = GetValidator(); validator.Initialize(new ValidatorContext(new object(), GetServiceProvider())); var spyHandler = new SpyHandler { HandleDelegate = (o, o1) => { o.ShouldEqual(validator); ((DataErrorsChangedMessage)o1).PropertyName.ShouldEqual(PropertyToValidate); ((DataErrorsChangedMessage)o1).IsAsyncValidate.ShouldEqual(isAsync); } }; validator.Subscribe(spyHandler).ShouldBeTrue(); validator.UpdateErrors(PropertyToValidate, ValidatorErrors, isAsync); isAsync = true; validator.UpdateErrors(PropertyToValidate, ValidatorErrors, isAsync); spyHandler.HandleCount.ShouldEqual(2); }