Add support for 8 digit IINs and 2 digit last_digits

[ugexe]

Previously issuer_id_number was expected to be 6 digits and
last_4_digits to be 4 digits. This changes the validation to
additionally allow for 8 digit issuer_id_numbers and 2 digit
last_4_digits.

Additionally last_4_digits has been deprecated in favor of the
more appropriately named last_digits.

[ugexe]

This doesn't feel like it belongs in the parameter list, but I wasn't familiar enough with this to determine how to express it more clearly. I assumed I would be able to apply the 2|4 valuation on last_digits in the parameter list and do additional validation based on the iin inside the function body but I couldn't get it to DWIM

[oschwald]

Yeah, that is a tricky one. I thought OneOf might work well here, but on reflection, we have to also handle the case where the keys aren't present. One possible improvement might be switching the When to:

             v::when(
                    v::key('issuer_id_number', v::stringType()->length(8, 8), false),
                    v::key('last_digits', v::stringType()->length(2, 2), false),
                    v::key('last_digits', v::stringType()->length(4, 4), false),
                ),

And moving the last_digits validation down. This should improve the error message and might make it a little bit easier to understand the logic.

[oschwald]

One comment. I'll leave it up to you whether you want to make the change.

[oschwald]

Yeah, that is a tricky one. I thought OneOf might work well here, but on reflection, we have to also handle the case where the keys aren't present. One possible improvement might be switching the When to:

             v::when(
                    v::key('issuer_id_number', v::stringType()->length(8, 8), false),
                    v::key('last_digits', v::stringType()->length(2, 2), false),
                    v::key('last_digits', v::stringType()->length(4, 4), false),
                ),

And moving the last_digits validation down. This should improve the error message and might make it a little bit easier to understand the logic.

[mrtimp]

@oschwald our credit card provider only returns the last 2 not 4 digits of a masked credit card so this PR is of interest for us. Do you have any idea when you will be tagging a new release?

[oschwald]

@mrtimp, I suspect we will be releasing this in the very near future, perhaps the next week or two.

[mrtimp]

Fantastic @oschwald! Look forward to it.