Rate code changed to be consistent across multiple rate requests

[speedupmate]

Rate code needs to be consistent accross all rate requests with same request data.

$rate['pk'] can't be used inside shipping method code. Pk (primary key) can change during requests while rates are deleted and requested again. primary key is not a warranted value and depends on rates being available for request across all available methods (more/less methods more/less keys etc)

to illustrate this:
at one reload your rate code can be matrixrate_matrixrate_344
on another reload the same rate can get a different code matrixrate_matrixrate_244

rate deletion is built in to magento totals collection flow, see Magento\Quote\Model\Quote\Address::collectShippingRates() method for details.

This change changes the code do be dependant on rate data instead of random key in database and rate code is unique per requested country + price offered (multiplied by 100)

to illustrate this:

• rate code for Finland with price 19.00 will become matrixrate_matrixrate_FI1900
• rate code for USA with price 19.00 will become matrixrate_matrixrate_US1900

[wsagen]

Hi Anton,

The "pk" value is the unique identifier for a rate (i.e. the table row) and will only change for that particular rate when a new CSV file is uploaded.
If you are not seeing the same rates returned during checkout flow, then there must be a difference in the request to Matrixrates meaning different rates are being returned.

If you enable logging you can view the rate requests and rows retrieved.

It's likely one of the outstanding issues with Magento 2 is the issue here, where the full address is not sent to carriers during the shipping method step, and is used during the payment and review step. So for example, if your CSV file includes region or postcode filtering, then there may be a difference in the actual rate returned.

We can't accept this change as it would break the uniqueness constraint on the shipping method code for many of our customer's CSV files. It's extremely common that customers would have identical rates for the same country, across many rows in a CSV file and this change would mean all of those rates had the exact same method code and were no longer unique.