[BANKCON-14524] Allow pay by bank when linkCardBrand criteria is met & dedupe instant debits

[mats-stripe]

Summary

Per the Panther project plan, this adds Link Card Brand as a payment method when the following criteria is met:

• link_funding_sources contains BANK_ACCOUNT
• US_BANK_ACCOUNT is not an available payment method.
• link_mode is LINK_CARD_BRAND

This also makes sure that both Instant Debits and Link Card Brand won't both be shown at the same time, since they appear as identical payment methods to a user (same name, icon, and elements form).

Motivation

Building Panther support!

Testing

Added a unit test, and manually verified the new payment method shows up when the conditions are met:

Screen.Recording.2024-09-17.at.9.18.47.AM.mov

Changelog

N/a

[kgaidis-stripe]

does this need to be a var instead of a let?

and out of curiosity/learning how does this compile?

I would have expected it to be something like:

            let eligibleForInstantDebits: Bool = {
                return elementsSession.orderedPaymentMethodTypes.contains(.link) &&
                !elementsSession.orderedPaymentMethodTypes.contains(.USBankAccount) &&
                !intent.isDeferredIntent &&
                elementsSession.linkFundingSources?.contains(.bankAccount) == true
            }()

I get the inferred return as they are no longer necessary.

But what are all the other pieces?

it almost looks like an in-line computed property but the declaration is inside of a function 🤔 so I am not immediately sure the step-by-step execution for it to compile into a boolean

[kgaidis-stripe]

Tried in Xcode and I guess it can't be a let because it is a computed property

Is there a name for computed properties inside of functions, and is this new or old? 🤔

[kgaidis-stripe]

💯

The base branch was changed.

[mats-stripe]

Putting this PR on hold until we have guardrails preventing this feature be shown to users while it is being built.

[mats-stripe]

I had to update this UI test. With Panther enabled there's a second payment method available in this scenario now, and so the Add a card text was no longer shown. Here's the changes to this screen with Panther:

Before (without Panther)	Now (with Panther)