public void ShouldHandleNullObjectsCorrectly()
{
var subject = new SportsAggregatorWeakReferences();
var observer1 = new NewsPaper();
var observer2 = new RadioStation();
var wr1 = subject.RegisterObserver(observer1);
var wr2 = subject.RegisterObserver(observer2);
observer1 = null;
//Demo code. don't do this in real life
GC.Collect();
GC.WaitForPendingFinalizers();
var gameResult = new GameResult
{
GameDate = DateTime.Now,
LosingScore = 1,
LosingTeam = "Chicago Cubs",
WinningScore = 5,
WinningTeam = "Cincinnati Reds"
};
subject.AddGameResult(gameResult);
//No longer need this line...
//subject.UnregisterObserver(wr1);
foreach (var foo in subject.Observers)
{
foo?.TryGetTarget(out var observer);
}
subject.UnregisterObserver(wr2);
Assert.Equal(0, subject.Observers.Count);
}
public void ShouldNotifyObserversOfGameResult()
{
var subject = new SportsAggregatorWeakReferences();
var observer1 = new NewsPaper();
var observer2 = new RadioStation();
var wr1 = subject.RegisterObserver(observer1);
var wr2 = subject.RegisterObserver(observer2);
var gameResult = new GameResult
{
GameDate = DateTime.Now,
LosingScore = 1,
LosingTeam = "Chicago Cubs",
WinningScore = 5,
WinningTeam = "Cincinnati Reds"
};
subject.AddGameResult(gameResult);
Assert.Equal(1, observer1.Results.Count);
Assert.Equal(1, observer2.Results.Count);
Assert.Same(gameResult, observer1.Results[0]);
Assert.Same(gameResult, observer2.Results[0]);
subject.UnregisterObserver(wr1);
subject.UnregisterObserver(wr2);
Assert.Equal(0, subject.Observers.Count);
}