EventTest.cs

// Validate fired event
[Test(Description = "Verify that prop changed fires [Mikael Deurell]")]
 public void Description_Changed_FiresPropertyChanged()
 {
     // Given the user wants to change the product description on a Product
     int notify = 0;
     var sut = new ProductViewModel();
     sut.PropertyChanged += (sender, e) =>
                                {
                                    if (e.PropertyName.Equals("Description"))
                                    {
                                        ++notify;
                                    }
                                };
     // When changing the Description displayed in a text field on the view bound to the View Model
     sut.Description = "new description";
     
     // Then PropertyChangeEvent is fired in the View Model in order to let WPF notify the View of the change
     Assert.That(notify, Is.EqualTo(1));
 }