public void UserInterfaceManager_can_add_ErrorMessages_and_retrieve_them() { const string errorMessage1 = "how dare you!"; const string errorMessage2 = "STOP IT!"; var messageQueue = new Queue<string>(); var userSession = new Mock<IUserSession>(); userSession.Setup(x => x.GetMessages()).Returns(messageQueue); var provider = new UserInterfaceManager(userSession.Object); provider.AddMessage(errorMessage1); provider.AddMessage(errorMessage2); var messages = provider.GetMessages(); messages.Count().ShouldEqual(2); }