public void adds_dish() { var newDish = new Dish { Name = "new", IngredientIds = new List <int> { 1, 2 } }; _mockIngredientRepository.Setup(m => m.Exists(1)).Returns(true); _mockIngredientRepository.Setup(m => m.Exists(2)).Returns(true); _restaurant.AddDish(newDish); _mockDishRepository.Verify(m => m.Add(newDish), Times.Once); }