public void Test_StartSession_ReturnsIdForSession() { var gameId = 6667; var game = new Game() { Id = gameId }; _mockGameStorage.GetSingle(game.Id).Returns(game.Some()); var errands = Enumerable.Range(1, 6).Select(i => new Errand { Id = i, Description = "Errand " + i }); _mockGameErrandStorage.GetForGame(game.Id).Returns(errands); var guid = Guid.NewGuid(); _mockGameSessionStorage.CreateSession(game, errands).Returns(guid); var result = _service.StartSession(gameId); Assert.AreEqual(guid, result); }