Tax calculation inaccuracy when invoice and order are created on different dates

[erikhansen]

In the current version of the extension, when an order and invoice are created on different dates, there may be a mismatch between the amount of tax calculated when the user created the order vs the amount of tax calculated when the invoice is created. Here is an example scenario:

• Merchant has store configured to “authorize only” during checkout
• Customer places order using CC on a tax holiday
• Merchant ships product three days later and creates shipment and invoice in Magento at the point of shipment
• AvaTax commits the tax using the invoice creation date

To fix this problem, the following change needs to be made:

• If the invoice/order creation dates are the same, the GetTax DocDate value will be the date the order/invoice was created.
• If the invoice/order creation dates are different, the GetTax DocDate value will be the invoice creation date and a TaxOverride object will be included. The TaxOverride.TaxDate will be the order creation date.