public void AddOrderSuccessfully() { Customer customer = new CustomerBuilder().GetCustomer(); Order order = new OrderBuilder().GetOrder(customer); var listOrders = new List <Order>(); listOrders.Add(order); _mockOrderRepository.Setup(x => x.Insert(order)).Verifiable(); _mockOrderRepository.Setup(x => x.GetByCustomerId(customer.Id)).Returns(listOrders.AsQueryable()); _service.Insert(order); var ordersFromRepo = _service.GetByCustomerId(customer.Id); _mockOrderRepository.Verify(x => x.Insert(order), Times.Once); Assert.True(ordersFromRepo.Count == 1); }