public void CheckedIn() { //GIVEN var store = new EventStore(); var history = new IEvent [] { new RoomCleaned("101"), new RoomCleaned("102"), new RoomCleaned("103"), new RoomCheckedIn("102") }; store.Append(history); //Then var checkedin = store.GetCheckedInRoomIds(); Assert.True(checkedin.Count() == 1); Assert.True(checkedin.First() == "102"); }