Set correct allow_redisplay value for spms with link (#4501)

## Summary
Set allow_redisplay value when signing up for link and saving a new
payment method

## Motivation
allow_redisplay was not being set.

## Testing
Updated existing test

## Changelog
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`CHANGELOG.md` and prefix the line with one of the following:
    - [Added] for new features.
    - [Changed] for changes in existing functionality.
    - [Deprecated] for soon-to-be removed features.
    - [Removed] for now removed features.
    - [Fixed] for any bug fixes.
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Author: wooj-stripe

Example/PaymentSheet Example/PaymentSheetUITest/PaymentSheetUITest.swift

@@ -2204,15 +2204,25 @@ class PaymentSheetLinkUITests: PaymentSheetUITestCase {
     }
 
     // Tests the #5 flow in PaymentSheet where the merchant enables saved payment methods, buyer has SPMs and first time Link user
-    func testLinkPaymentSheet_enabledSPM_hasSPMs_firstTimeLinkUser() {
+    func testLinkPaymentSheet_enabledSPM_hasSPMs_firstTimeLinkUser_legacy() {
         var settings = PaymentSheetTestPlaygroundSettings.defaultValues()
         settings.layout = .horizontal
         settings.customerMode = .new
         settings.apmsEnabled = .on
         settings.linkPassthroughMode = .pm
-        // TODO: Properly pass the allow_redisplay value to 'consumers/payment_details' endpoint
         settings.customerKeyType = .legacy
-
+        _testLinkPaymentSheet_enabledSPM_hasSPMs_firstTimeLinkUser(settings: settings)
+    }
+    func testLinkPaymentSheet_enabledSPM_hasSPMs_firstTimeLinkUser_customerSession() {
+        var settings = PaymentSheetTestPlaygroundSettings.defaultValues()
+        settings.layout = .horizontal
+        settings.customerMode = .new
+        settings.apmsEnabled = .on
+        settings.linkPassthroughMode = .pm
+        settings.customerKeyType = .customerSession
+        _testLinkPaymentSheet_enabledSPM_hasSPMs_firstTimeLinkUser(settings: settings)
+    }
+    func _testLinkPaymentSheet_enabledSPM_hasSPMs_firstTimeLinkUser(settings: PaymentSheetTestPlaygroundSettings) {
         loadPlayground(app, settings)
         app.buttons["Present PaymentSheet"].waitForExistenceAndTap()
 

StripePaymentSheet/StripePaymentSheet/Source/Helpers/PaymentSheetLinkAccount.swift

@@ -364,7 +364,7 @@ class PaymentSheetLinkAccount: PaymentSheetLinkAccountInfoProtocol {
         }
     }
 
-    func sharePaymentDetails(id: String, cvc: String?, completion: @escaping (Result<PaymentDetailsShareResponse, Error>) -> Void) {
+    func sharePaymentDetails(id: String, cvc: String?, allowRedisplay: STPPaymentMethodAllowRedisplay?, completion: @escaping (Result<PaymentDetailsShareResponse, Error>) -> Void) {
         retryingOnAuthError(completion: completion) { [apiClient, publishableKey] completionRetryingOnAuthErrors in
             guard let session = self.currentSession else {
                 stpAssertionFailure()
@@ -379,6 +379,7 @@ class PaymentSheetLinkAccount: PaymentSheetLinkAccountInfoProtocol {
                 with: apiClient,
                 id: id,
                 cvc: cvc,
+                allowRedisplay: allowRedisplay,
                 consumerAccountPublishableKey: publishableKey,
                 completion: completionRetryingOnAuthErrors
             )

StripePaymentSheet/StripePaymentSheet/Source/Internal/API Bindings/Link/ConsumerSession.swift

@@ -238,13 +238,15 @@ extension ConsumerSession {
         with apiClient: STPAPIClient = STPAPIClient.shared,
         id: String,
         cvc: String?,
+        allowRedisplay: STPPaymentMethodAllowRedisplay?,
         consumerAccountPublishableKey: String?,
         completion: @escaping (Result<PaymentDetailsShareResponse, Error>) -> Void
     ) {
         apiClient.sharePaymentDetails(
             for: clientSecret,
             id: id,
             consumerAccountPublishableKey: consumerAccountPublishableKey,
+            allowRedisplay: allowRedisplay,
             cvc: cvc,
             completion: completion)
     }

StripePaymentSheet/StripePaymentSheet/Source/Internal/API Bindings/Link/STPAPIClient+Link.swift

@@ -286,6 +286,7 @@ extension STPAPIClient {
         for consumerSessionClientSecret: String,
         id: String,
         consumerAccountPublishableKey: String?,
+        allowRedisplay: STPPaymentMethodAllowRedisplay?,
         cvc: String?,
         completion: @escaping (Result<PaymentDetailsShareResponse, Error>) -> Void
     ) {
@@ -301,6 +302,9 @@ extension STPAPIClient {
         if let cvc = cvc {
             parameters["payment_method_options"] = ["card": ["cvc": cvc]]
         }
+        if let allowRedisplay {
+            parameters["allow_redisplay"] = allowRedisplay.stringValue
+        }
 
         APIRequest<PaymentDetailsShareResponse>.post(
             with: self,

StripePaymentSheet/StripePaymentSheet/Source/PaymentSheet/PaymentSheet+API.swift

@@ -456,7 +456,7 @@ extension PaymentSheet {
                         case .success(let paymentDetails):
                             if elementsSession.linkPassthroughModeEnabled {
                                 // If passthrough mode, share payment details
-                                linkAccount.sharePaymentDetails(id: paymentDetails.stripeID, cvc: paymentMethodParams.card?.cvc) { result in
+                                linkAccount.sharePaymentDetails(id: paymentDetails.stripeID, cvc: paymentMethodParams.card?.cvc, allowRedisplay: paymentMethodParams.allowRedisplay) { result in
                                     switch result {
                                     case .success(let paymentDetailsShareResponse):
                                         confirmWithPaymentMethod(paymentDetailsShareResponse.paymentMethod, linkAccount, shouldSave)
@@ -495,6 +495,11 @@ extension PaymentSheet {
                     switch result {
                     case .success:
                         STPAnalyticsClient.sharedClient.logLinkSignupComplete()
+                        // Set allow_redisplay on params
+                        intentConfirmParams.setAllowRedisplay(
+                            mobilePaymentElementFeatures: elementsSession.customerSessionMobilePaymentElementFeatures,
+                            isSettingUp: intent.isSettingUp
+                        )
                         createPaymentDetailsAndConfirm(linkAccount, intentConfirmParams.paymentMethodParams, intentConfirmParams.saveForFutureUseCheckboxState == .selected)
                     case .failure(let error as NSError):
                         STPAnalyticsClient.sharedClient.logLinkSignupFailure(error: error)
@@ -508,7 +513,8 @@ extension PaymentSheet {
                 let shouldSave = false // always false, as we don't show a save-to-merchant checkbox in Link VC
 
                 if elementsSession.linkPassthroughModeEnabled {
-                    linkAccount.sharePaymentDetails(id: paymentDetails.stripeID, cvc: paymentDetails.cvc) { result in
+                    // allowRedisplay is nil since we are not saving a payment method.
+                    linkAccount.sharePaymentDetails(id: paymentDetails.stripeID, cvc: paymentDetails.cvc, allowRedisplay: nil) { result in
                         switch result {
                         case .success(let paymentDetailsShareResponse):
                             confirmWithPaymentMethod(paymentDetailsShareResponse.paymentMethod, linkAccount, shouldSave)

StripePayments/StripePayments/Source/API Bindings/Models/PaymentMethods/STPPaymentMethodAllowRedisplay.swift

@@ -16,7 +16,7 @@ import Foundation
     /// Use always to indicate that this payment method can always be shown to a customer in a checkout flow.
     case always
 
-    var stringValue: String? {
+    @_spi(STP) public var stringValue: String? {
         switch self {
         case .unspecified:
             return "unspecified"