public void CreateRetailLineItems_CreatesOneRetailLineItemPerScannedItem() { AddFullSetOfScannedItemsToOrder(); var lineItems = InvoiceFactory.CreateRetailLineItems(_order.ScannedItems); var lineItemScannedItemIds = lineItems.Select(x => ((RetailLineItem)x).ScannedItemId).ToList(); lineItemScannedItemIds.Should().OnlyHaveUniqueItems(); lineItemScannedItemIds.Should().BeEquivalentTo(_order.ScannedItems.Select(x => x.Id)); }