Support Instant Debits with deferred intents

StripeCore/StripeCore.xcodeproj/project.pbxproj

@@ -106,6 +106,7 @@
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 		CAF857D45689FBEF17627E80 /* BundleLocatorProtocol.swift in Sources */ = {isa = PBXBuildFile; fileRef = 937066801E91C99C50192364 /* BundleLocatorProtocol.swift */; };
+		CB0E9DC82CB9C79E00E083D1 /* LinkBankPaymentMethod.swift in Sources */ = {isa = PBXBuildFile; fileRef = CB0E9DC72CB9C79E00E083D1 /* LinkBankPaymentMethod.swift */; };
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@@ -318,6 +319,7 @@
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 		C51179DB520568C246BF3AF0 /* URLEncoder.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = URLEncoder.swift; sourceTree = "<group>"; };
 		C666CC926642D7AA76E75B5B /* StripeCoreTestUtils.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = StripeCoreTestUtils.h; sourceTree = "<group>"; };
+		CB0E9DC72CB9C79E00E083D1 /* LinkBankPaymentMethod.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = LinkBankPaymentMethod.swift; sourceTree = "<group>"; };
 		CB2721EE8E075E700FF3E58A /* StripeiOS-Release.xcconfig */ = {isa = PBXFileReference; lastKnownFileType = text.xcconfig; path = "StripeiOS-Release.xcconfig"; sourceTree = "<group>"; };
 		CC70CDF482E22A29B11466F7 /* STPAPIClient+EmptyResponseTest.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "STPAPIClient+EmptyResponseTest.swift"; sourceTree = "<group>"; };
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@@ -456,6 +458,7 @@
 				6A05FB4A2BCF245C0001D128 /* FinancialConnectionsEvent.swift */,
 				493B33052CA3015600E3622F /* LinkMode.swift */,
 				492039922CA47A8600CE2072 /* ElementsSessionContext.swift */,
+				CB0E9DC72CB9C79E00E083D1 /* LinkBankPaymentMethod.swift */,
 			);
 			path = "Connections Bindings";
 			sourceTree = "<group>";
@@ -1019,6 +1022,7 @@
 				096274D0729AA8849FAD103C /* PaymentsSDKVariant.swift in Sources */,
 				DA5A05459309B9B77ACDD736 /* STPDeviceUtils.swift in Sources */,
 				4910B9282C3D8F3F00B030D4 /* Result+Extensions.swift in Sources */,
+				CB0E9DC82CB9C79E00E083D1 /* LinkBankPaymentMethod.swift in Sources */,
 				83790210FFC2DD764C042C8E /* STPDispatchFunctions.swift in Sources */,
 				72DA29CA8A750E8B00DBF3D4 /* STPError.swift in Sources */,
 				F628BBE9FDA9D3A217ACA753 /* STPNumericStringValidator.swift in Sources */,

StripeCore/StripeCore/Source/Connections Bindings/InstantDebitsLinkedBank.swift

@@ -7,18 +7,19 @@
 
 import Foundation
 
-@_spi(STP) public struct InstantDebitsLinkedBank: Equatable {
-    public let paymentMethodId: String
+@_spi(STP) public struct InstantDebitsLinkedBank {
+    public let paymentMethod: LinkBankPaymentMethod
     public let bankName: String?
     public let last4: String?
     public let linkMode: LinkMode?
+
     public init(
-        paymentMethodId: String,
+        paymentMethod: LinkBankPaymentMethod,
         bankName: String?,
         last4: String?,
         linkMode: LinkMode?
     ) {
-        self.paymentMethodId = paymentMethodId
+        self.paymentMethod = paymentMethod
         self.bankName = bankName
         self.last4 = last4
         self.linkMode = linkMode

StripeCore/StripeCore/Source/Connections Bindings/LinkBankPaymentMethod.swift

@@ -0,0 +1,16 @@
+//
+//  LinkBankPaymentMethod.swift
+//  StripeCore
+//
+//  Created by Till Hellmund on 10/11/24.
+//
+
+import Foundation
+
+/// This struct represents the encoded `PaymentMethod` that we receive during the Instant Debits flow.
+/// We don't decode it into a proper struct to prevent said struct (which would live in StripeCore) from getting
+/// out-of-sync with `STPPaymentMethod`, which this payment method will eventually be decoded into.
+@_spi(STP) public struct LinkBankPaymentMethod: UnknownFieldsDecodable {
+    public var _allResponseFieldsStorage: NonEncodableParameters?
+    public var id: String
+}

StripeFinancialConnections/StripeFinancialConnections/Source/API Bindings/FinancialConnectionsAPIClient.swift

@@ -242,7 +242,7 @@ protocol FinancialConnectionsAPI {
     func paymentMethods(
         consumerSessionClientSecret: String,
         paymentDetailsId: String
-    ) -> Future<FinancialConnectionsPaymentMethod>
+    ) -> Future<LinkBankPaymentMethod>
 }
 
 extension FinancialConnectionsAPIClient: FinancialConnectionsAPI {
@@ -1021,7 +1021,7 @@ extension FinancialConnectionsAPIClient: FinancialConnectionsAPI {
     func paymentMethods(
         consumerSessionClientSecret: String,
         paymentDetailsId: String
-    ) -> Future<FinancialConnectionsPaymentMethod> {
+    ) -> Future<LinkBankPaymentMethod> {
         let parameters: [String: Any] = [
             "link": [
                 "credentials": [
@@ -1033,7 +1033,7 @@ extension FinancialConnectionsAPIClient: FinancialConnectionsAPI {
         ]
 
         return updateAndApplyFraudDetection(to: parameters)
-            .chained { [weak self] parametersWithTelemetry -> Future<FinancialConnectionsPaymentMethod> in
+            .chained { [weak self] parametersWithTelemetry -> Future<LinkBankPaymentMethod> in
                 guard let self else {
                     return Promise(
                         error: FinancialConnectionsSheetError.unknown(debugDescription: "FinancialConnectionsAPIClient was deallocated.")

StripeFinancialConnections/StripeFinancialConnections/Source/API Bindings/Models/FinancialConnectionsPaymentDetails.swift

@@ -6,10 +6,7 @@
 //
 
 import Foundation
-
-protocol PaymentMethodIDProvider {
-    var id: String { get }
-}
+@_spi(STP) import StripeCore
 
 struct FinancialConnectionsPaymentDetails: Decodable {
     let redactedPaymentDetails: RedactedPaymentDetails
@@ -25,15 +22,6 @@ struct BankAccountDetails: Decodable {
     let last4: String?
 }
 
-struct FinancialConnectionsPaymentMethod: Decodable {
-    let id: String
-}
-
 struct FinancialConnectionsSharePaymentDetails: Decodable {
-    let paymentMethod: FinancialConnectionsPaymentMethod
-}
-
-extension FinancialConnectionsPaymentMethod: PaymentMethodIDProvider {}
-extension FinancialConnectionsSharePaymentDetails: PaymentMethodIDProvider {
-    var id: String { paymentMethod.id }
+    let paymentMethod: LinkBankPaymentMethod
 }

StripeFinancialConnections/StripeFinancialConnections/Source/FinancialConnectionsSheet.swift

@@ -151,7 +151,7 @@ final public class FinancialConnectionsSheet {
                         let errorDescription = "Instant Debits is not currently supported via this interface."
                         let sessionInfo =
                         """
-                        paymentMethodId=\(linkedBank.paymentMethodId)
+                        paymentMethodId=\(linkedBank.paymentMethod.id)
                         bankName=\(linkedBank.bankName ?? "N/A")
                         last4=\(linkedBank.last4 ?? "N/A")
                         """

StripeFinancialConnections/StripeFinancialConnections/Source/Native/NativeFlowController.swift

@@ -513,7 +513,7 @@ extension NativeFlowController {
             consumerSessionClientSecret: consumerSession.clientSecret,
             bankAccountId: bankAccountId
         )
-        .chained { [weak self] paymentDetails -> Future<PaymentMethodIDProvider> in
+        .chained { [weak self] paymentDetails -> Future<LinkBankPaymentMethod> in
             guard let self else {
                 return Promise(error: FinancialConnectionsSheetError.unknown(debugDescription: "data source deallocated"))
             }
@@ -527,20 +527,19 @@ extension NativeFlowController {
                     paymentDetailsId: paymentDetails.redactedPaymentDetails.id,
                     expectedPaymentMethodType: linkMode.expectedPaymentMethodType
                 )
-                .transformed { $0 as PaymentMethodIDProvider }
+                .transformed { $0.paymentMethod }
             } else {
                 return self.dataManager.createPaymentMethod(
                     consumerSessionClientSecret: consumerSession.clientSecret,
                     paymentDetailsId: paymentDetails.redactedPaymentDetails.id
                 )
-                .transformed { $0 as PaymentMethodIDProvider }
             }
         }
         .observe { result in
             switch result {
             case .success(let paymentMethod):
                 let linkedBank = InstantDebitsLinkedBank(
-                    paymentMethodId: paymentMethod.id,
+                    paymentMethod: paymentMethod,
                     bankName: bankAccountDetails?.bankName,
                     last4: bankAccountDetails?.last4,
                     linkMode: linkMode

StripeFinancialConnections/StripeFinancialConnections/Source/Native/NativeFlowDataManager.swift

@@ -43,7 +43,7 @@ protocol NativeFlowDataManager: AnyObject {
     func createPaymentMethod(
         consumerSessionClientSecret: String,
         paymentDetailsId: String
-    ) -> Future<FinancialConnectionsPaymentMethod>
+    ) -> Future<LinkBankPaymentMethod>
     func resetState(withNewManifest newManifest: FinancialConnectionsSessionManifest)
     func completeFinancialConnectionsSession(terminalError: String?) -> Future<StripeAPI.FinancialConnectionsSession>
 }
@@ -151,7 +151,7 @@ class NativeFlowAPIDataManager: NativeFlowDataManager {
     func createPaymentMethod(
         consumerSessionClientSecret: String,
         paymentDetailsId: String
-    ) -> Future<FinancialConnectionsPaymentMethod> {
+    ) -> Future<LinkBankPaymentMethod> {
         apiClient.paymentMethods(
             consumerSessionClientSecret: consumerSessionClientSecret,
             paymentDetailsId: paymentDetailsId

StripeFinancialConnections/StripeFinancialConnections/Source/Web/FinancialConnectionsWebFlowViewController.swift

@@ -166,22 +166,20 @@ extension FinancialConnectionsWebFlowViewController {
                 switch result {
                 case .success(.success(let returnUrl)):
                     if manifest.isProductInstantDebits {
-                        if
-                            let paymentMethodId = Self.extractValue(from: returnUrl, key: "payment_method_id")
-                        {
+                        if let paymentMethod = returnUrl.extractLinkBankPaymentMethod() {
                             let instantDebitsLinkedBank = InstantDebitsLinkedBank(
-                                paymentMethodId: paymentMethodId,
-                                bankName: Self.extractValue(from: returnUrl, key: "bank_name")?
+                                paymentMethod: paymentMethod,
+                                bankName: returnUrl.extractValue(forKey: "bank_name")?
                                 // backend can return "+" instead of a more-common encoding of "%20" for spaces
                                     .replacingOccurrences(of: "+", with: " "),
-                                last4: Self.extractValue(from: returnUrl, key: "last4"),
+                                last4: returnUrl.extractValue(forKey: "last4"),
                                 linkMode: elementsSessionContext?.linkMode
                             )
                             self.notifyDelegateOfSuccess(result: .instantDebits(instantDebitsLinkedBank))
                         } else {
                             self.notifyDelegateOfFailure(
                                 error: FinancialConnectionsSheetError.unknown(
-                                    debugDescription: "payment_method_id was not returned"
+                                    debugDescription: "Invalid payment_method returned"
                                 )
                             )
                         }
@@ -292,9 +290,24 @@ extension FinancialConnectionsWebFlowViewController {
 
         notifyDelegate(result: .failed(error: error))
     }
+}
 
-    private static func extractValue(from url: URL, key: String) -> String? {
-        guard let components = URLComponents(url: url, resolvingAgainstBaseURL: false) else {
+private extension URL {
+
+    func extractLinkBankPaymentMethod() -> LinkBankPaymentMethod? {
+        guard let encodedPaymentMethod = extractValue(forKey: "payment_method") else {
+            return nil
+        }
+
+        guard let data = Data(base64Encoded: encodedPaymentMethod) else {
+            return nil
+        }
+
+        return try? JSONDecoder().decode(LinkBankPaymentMethod.self, from: data)
+    }
+
+    func extractValue(forKey key: String) -> String? {
+        guard let components = URLComponents(url: self, resolvingAgainstBaseURL: false) else {
             assertionFailure("Invalid URL")
             return nil
         }

StripeFinancialConnections/StripeFinancialConnectionsTests/EmptyFinancialConnectionsAPIClient.swift

@@ -223,7 +223,7 @@ class EmptyFinancialConnectionsAPIClient: FinancialConnectionsAPI {
         Promise<StripeFinancialConnections.FinancialConnectionsSharePaymentDetails>()
     }
 
-    func paymentMethods(consumerSessionClientSecret: String, paymentDetailsId: String) -> StripeCore.Future<StripeFinancialConnections.FinancialConnectionsPaymentMethod> {
-        Promise<StripeFinancialConnections.FinancialConnectionsPaymentMethod>()
+    func paymentMethods(consumerSessionClientSecret: String, paymentDetailsId: String) -> StripeCore.Future<StripeFinancialConnections.LinkBankPaymentMethod> {
+        Promise<StripeFinancialConnections.LinkBankPaymentMethod>()
     }
 }

StripePaymentSheet/StripePaymentSheet/Source/PaymentSheet/PaymentMethodType.swift

@@ -173,7 +173,6 @@ extension PaymentSheet {
             var eligibleForInstantDebits: Bool {
                 elementsSession.orderedPaymentMethodTypes.contains(.link) &&
                 !elementsSession.orderedPaymentMethodTypes.contains(.USBankAccount) &&
-                !intent.isDeferredIntent &&
                 elementsSession.linkFundingSources?.contains(.bankAccount) == true
             }
 
@@ -185,7 +184,6 @@ extension PaymentSheet {
             var eligibleForLinkCardBrand: Bool {
                 elementsSession.linkFundingSources?.contains(.bankAccount) == true &&
                 !elementsSession.orderedPaymentMethodTypes.contains(.USBankAccount) &&
-                !intent.isDeferredIntent &&
                 elementsSession.linkSettings?.linkMode == .linkCardBrand
             }
 

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

@@ -149,7 +149,7 @@ extension PaymentSheet {
                     configuration: configuration
                 )
                 if case .new(let confirmParams) = paymentOption {
-                    if let paymentMethodId = confirmParams.instantDebitsLinkedBank?.paymentMethodId {
+                    if let paymentMethodId = confirmParams.instantDebitsLinkedBank?.paymentMethod.id {
                         params.paymentMethodId = paymentMethodId
                         params.paymentMethodParams = nil
 
@@ -180,7 +180,7 @@ extension PaymentSheet {
                     configuration: configuration
                 )
                 if case .new(let confirmParams) = paymentOption {
-                    if let paymentMethodId = confirmParams.instantDebitsLinkedBank?.paymentMethodId {
+                    if let paymentMethodId = confirmParams.instantDebitsLinkedBank?.paymentMethod.id {
                         setupIntentParams.paymentMethodID = paymentMethodId
                         setupIntentParams.paymentMethodParams = nil
                         setupIntentParams.mandateData = STPMandateDataParams.makeWithInferredValues()
@@ -198,12 +198,27 @@ extension PaymentSheet {
                 )
             // MARK: ↪ Deferred Intent
             case .deferredIntent(let intentConfig):
-                handleDeferredIntentConfirmation(
-                    confirmType: .new(
+                let confirmType: ConfirmPaymentMethodType? = if let bank = confirmParams.instantDebitsLinkedBank {
+                    if let paymentMethod = bank.paymentMethod.decode() {
+                        .saved(paymentMethod, paymentOptions: confirmParams.confirmPaymentMethodOptions)
+                    } else {
+                        nil
+                    }
+                } else {
+                    .new(
                         params: confirmParams.paymentMethodParams,
                         paymentOptions: confirmParams.confirmPaymentMethodOptions,
                         shouldSave: confirmParams.saveForFutureUseCheckboxState == .selected
-                    ),
+                    )
+                }
+
+                guard let confirmType else {
+                    completion(.failed(error: PaymentSheetError.invalidLinkBankPaymentMethod), nil)
+                    return
+                }
+
+                handleDeferredIntentConfirmation(
+                    confirmType: confirmType,
                     configuration: configuration,
                     intentConfig: intentConfig,
                     authenticationContext: authenticationContext,
@@ -654,3 +669,10 @@ private func isEqual(_ lhs: STPPaymentIntentShippingDetails?, _ rhs: STPPaymentI
 
     return rhs == lhsConverted
 }
+
+private extension LinkBankPaymentMethod {
+
+    func decode() -> STPPaymentMethod? {
+        return STPPaymentMethod.decodedObject(fromAPIResponse: allResponseFields)
+    }
+}

StripePaymentSheet/StripePaymentSheet/Source/PaymentSheet/PaymentSheetError.swift

@@ -41,6 +41,7 @@ public enum PaymentSheetError: Error, LocalizedError {
     // MARK: Deferred intent errors
     case intentConfigurationValidationFailed(message: String)
     case deferredIntentValidationFailed(message: String)
+    case invalidLinkBankPaymentMethod
 
     // MARK: - Link errors
     case linkSignUpNotRequired
@@ -79,6 +80,8 @@ extension PaymentSheetError: CustomDebugStringConvertible {
                 return "Attempted Apple Pay but it's not supported by the device, not configured, or missing a presenter"
             case .deferredIntentValidationFailed(message: let message):
                 return message
+            case .invalidLinkBankPaymentMethod:
+                return "The Stripe API sent an invalid payment_method parameter"
             case .alreadyPresented:
                 return "presentingViewController is already presenting a view controller"
             case .flowControllerConfirmFailed(message: let message):

StripePaymentSheet/StripePaymentSheet/Source/PaymentSheet/ViewControllers/PaymentMethodFormViewController.swift

@@ -200,7 +200,6 @@ struct OverridePrimaryButtonState {
 extension PaymentMethodFormViewController {
     enum Error: Swift.Error {
         case usBankAccountParamsMissing
-        case instantDebitsDeferredIntentNotSupported
         case instantDebitsParamsMissing
     }
 
@@ -417,7 +416,7 @@ extension PaymentMethodFormViewController {
         }
         let additionalParameters: [String: Any] = [
             "product": "instant_debits",
-            "attach_required": true,
+//            "attach_required": true,
             "hosted_surface": "payment_element",
         ]
         switch intent {
@@ -443,13 +442,29 @@ extension PaymentMethodFormViewController {
                 from: viewController,
                 financialConnectionsCompletion: financialConnectionsCompletion
             )
-        case .deferredIntent: // not supported
-            let errorAnalytic = ErrorAnalytic(
-                event: .unexpectedPaymentSheetError,
-                error: Error.instantDebitsDeferredIntentNotSupported
+        case .deferredIntent(let intentConfig):
+            let amount: Int?
+            let currency: String?
+            switch intentConfig.mode {
+            case let .payment(amount: _amount, currency: _currency, _, _):
+                amount = _amount
+                currency = _currency
+            case let .setup(currency: _currency, _):
+                amount = nil
+                currency = _currency
+            }
+            client.collectBankAccountForDeferredIntent(
+                sessionId: elementsSession.sessionID,
+                returnURL: configuration.returnURL,
+                onEvent: nil,
+                amount: amount,
+                currency: currency,
+                onBehalfOf: intentConfig.onBehalfOf,
+                additionalParameters: additionalParameters,
+                elementsSessionContext: elementsSessionContext,
+                from: viewController,
+                financialConnectionsCompletion: financialConnectionsCompletion
             )
-            STPAnalyticsClient.sharedClient.log(analytic: errorAnalytic)
-            stpAssertionFailure()
         }
     }
 }