public void AddNewOrder_ShouldReturn_OrderContextWithOneMoreOrder() { int originalNumber = this._context.Orders.Count(); int orderId = this._context.SugarSachets.FirstOrDefault().Id; var newOrderBm = new Mock <NewOrderBm>(); newOrderBm.Object.PaperKg = 234; newOrderBm.Object.Id = orderId; _service.AddNewOrder(newOrderBm.Object); int ordersAfterInsert = _context.Orders.Count(); Assert.AreEqual(originalNumber + 1, ordersAfterInsert); }