public void ScoreboardShouldDisplayScoresWhenThereAreAny() { var mockSerializer = new Mock<IScoreSerializer>(); mockSerializer.Setup(s => s.Load()).Returns(this.scores); mockSerializer.Setup(s => s.Save(It.IsAny<IList<Score>>())); serializer = mockSerializer.Object; var mockNotifier = new Mock<IScoreNotifier>(); mockNotifier.Setup(n => n.Notify(It.IsAny<string>())).Verifiable(); mockNotifier.Setup(n => n.DisplayScores(It.IsAny<IList<Score>>())); this.notifier = mockNotifier.Object; var scoreBoard = new Scoreboard(notifier, serializer, actionsReader); scoreBoard.DisplayTopScores(); mockNotifier.Verify(n => n.DisplayScores(It.IsAny<IList<Score>>()), Times.Once); }