[11.x] WIP: SEPA Debit support

[lsmith77]

see #435

Note when setting up the intent it is necessary to specifiy "seba_debit", f.e. if you want to allow both card and sepa_debit:

        $options = [
            'payment_method_types' => ['card', 'sepa_debit']
        ];

        $setupIntent = SetupIntent::create($options, Cashier::stripeOptions());

I managed to do a charge in testmode inside my Spark app (needed to do some modifications of course inside the Spark app too). Also noticed that there seems to be a 10k EUR limit on my account and I wanted to charge 10.8k EUR .. doh .. but with a lower amount it worked.

[lsmith77]

following the example of Bank Account here .. obviously we could also store the bank_code here but I guess in most cases people just want to know if its a SEPA payment method:
https://stripe.com/docs/api/payment_methods/object#payment_method_object-card-generated_from-payment_method_details-sepa_debit-bank_code

[driesvints]

Doesn't the below work?

Suggested change

	['type' => 'card'] + $parameters,
	['type' => ['card', 'sepa_debit']] + $parameters,

[lsmith77]

let me check once more .. IIRC I ran into issues.

[lsmith77]

unfortunately this gives an Invalid string: {:"0"=>"card", :"1"=>"sepa_debit"}

[driesvints]

Thanks for the PR. This will still need to be fleshed out a lot more with tests, an update to the payment.blade.php page and some updates to the PaymentMethod class. I might have some time this week to look at this.

[lsmith77]

I can look into doing those additional fixes sometime this week.

BTW I assume this should go into master .. or could it also go into 10.x ?
Spark is currently locked on cashier 10.x and a specific stripe API version which conflicts with master.

[driesvints]

Definitely master.

[lsmith77]

I just added some changes to payment.blade.php .. not tested at all.

I looked at PaymentMethod and did't see what should be added there.
Would you prefer if the SEPA Debit string we defined over there?

[lsmith77]

not sure how soon I get some more time for this .. tests are obviously also still missing.

[driesvints]

@lsmith77 think yu still need to push your changes?

[lsmith77]

oops .. tried to push to origin .. pushed

[lsmith77]

just rebased on master.

[driesvints]

@lsmith77 we made the decision to not include SEPA for now. There's still quite a bit of work with this PR and we'll need to test various scenarios regarding SCA, failed payments, delayed notifications. We want to get v11 finally out of the door now and will look again at this PR for v12 maybe. Thanks for your work. Don't consider this lost, I'll re-look at this once I get to it.

[lsmith77]

ok. no worries. if I bring this to prod on my side I can do this in a fork. just wondering how do you plan to retain the work for v12? I guess a closed PR will remain available and its linked in the issue that remains open.

[driesvints]

@lsmith77 yeah the code is still here and the issue is linked 👍