/// <summary>
/// Asserts that an object has raised the <see cref="INotifyPropertyChanged.PropertyChanged"/> event for a particular property.
/// </summary>
/// <param name="eventSource">The object exposing the event.</param>
/// <param name="propertyExpression">
/// A lambda expression referring to the property for which the property changed event should have been raised, or
/// <c>null</c> to refer to all properties.
/// </param>
/// <param name="reason">
/// A formatted phrase explaining why the assertion should be satisfied. If the phrase does not
/// start with the word <i>because</i>, it is prepended to the message.
/// </param>
/// <param name="reasonArgs">
/// Zero or more values to use for filling in any <see cref="string.Format(string,object[])"/> compatible placeholders.
/// </param>
/// <remarks>
/// You must call <see cref="MonitorEvents"/> on the same object prior to this call so that Fluent Assertions can
/// subscribe for the events of the object.
/// </remarks>
public static IEventRecorder ShouldRaisePropertyChangeFor <T>(
this T eventSource, Expression <Func <T, object> > propertyExpression,
string reason, params object[] reasonArgs)
{
EventRecorder eventRecorder = eventSource.GetRecorderForEvent(PropertyChangedEventName);
string propertyName = (propertyExpression != null) ? propertyExpression.GetPropertyInfo().Name : null;
if (!eventRecorder.Any())
{
Execute.Assertion
.BecauseOf(reason, reasonArgs)
.FailWith("Expected object {0} to raise event {1} for property {2}{reason}, but it did not.",
eventSource, PropertyChangedEventName, propertyName);
}
return(eventRecorder.WithArgs <PropertyChangedEventArgs>(args => args.PropertyName == propertyName));
}