Improve link form regeneration

Stripe/StripeiOSTests/LinkInlineSignupElementSnapshotTests.swift

@@ -148,6 +148,7 @@ extension LinkInlineSignupElementSnapshotTests {
             configuration: configuration,
             showCheckbox: showCheckbox,
             accountService: MockAccountService(),
+            previousCustomerInput: nil,
             linkAccount: linkAccount,
             country: country
         )

Stripe/StripeiOSTests/LinkSignupViewModelTests.swift

@@ -12,7 +12,6 @@ import StripeCoreTestUtils
 import XCTest
 
 @testable@_spi(STP) import Stripe
-@testable@_spi(STP) import StripeCore
 @testable@_spi(STP) import StripePayments
 @testable@_spi(STP) import StripePaymentSheet
 import StripePaymentsTestUtils
@@ -208,6 +207,7 @@ extension LinkInlineSignupViewModelTests {
             configuration: PaymentSheet.Configuration(),
             showCheckbox: showCheckbox,
             accountService: MockAccountService(shouldFailLookup: shouldFailLookup),
+            previousCustomerInput: nil,
             linkAccount: linkAccount,
             country: country
         )

StripePaymentSheet/StripePaymentSheet.xcodeproj/project.pbxproj

@@ -216,6 +216,7 @@
 		B615E8752CA4CC38007D684C /* EmbeddedPaymentElementDelegate.swift in Sources */ = {isa = PBXBuildFile; fileRef = B615E8742CA4CC38007D684C /* EmbeddedPaymentElementDelegate.swift */; };
 		B61E2C202C5C44FE0045B5CF /* PaymentSheetAnalyticsHelper.swift in Sources */ = {isa = PBXBuildFile; fileRef = B61E2C1F2C5C44FE0045B5CF /* PaymentSheetAnalyticsHelper.swift */; };
 		B626EE932BF2872200B05B05 /* PaymentMethodTypeImageView.swift in Sources */ = {isa = PBXBuildFile; fileRef = B626EE922BF2872200B05B05 /* PaymentMethodTypeImageView.swift */; };
+		B62934F22CAE0ACC009F7C8F /* CardSectionElementTest.swift in Sources */ = {isa = PBXBuildFile; fileRef = B62934F12CAE0ACC009F7C8F /* CardSectionElementTest.swift */; };
 		B63B2CF12BF8313D003810F3 /* VerticalPaymentMethodListViewControllerTest.swift in Sources */ = {isa = PBXBuildFile; fileRef = B63B2CF02BF8313D003810F3 /* VerticalPaymentMethodListViewControllerTest.swift */; };
 		B63B2CF32BFBEE7B003810F3 /* VerticalPaymentMethodListViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = B63B2CF22BFBEE7B003810F3 /* VerticalPaymentMethodListViewController.swift */; };
 		B63B2CF52BFBEEAD003810F3 /* PaymentMethodFormViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = B63B2CF42BFBEEAD003810F3 /* PaymentMethodFormViewController.swift */; };
@@ -582,6 +583,7 @@
 		B61E2C1F2C5C44FE0045B5CF /* PaymentSheetAnalyticsHelper.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PaymentSheetAnalyticsHelper.swift; sourceTree = "<group>"; };
 		B61FFE76D0960C7F1E34B405 /* PaymentSheetAppearance.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PaymentSheetAppearance.swift; sourceTree = "<group>"; };
 		B626EE922BF2872200B05B05 /* PaymentMethodTypeImageView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PaymentMethodTypeImageView.swift; sourceTree = "<group>"; };
+		B62934F12CAE0ACC009F7C8F /* CardSectionElementTest.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CardSectionElementTest.swift; sourceTree = "<group>"; };
 		B63B2CF02BF8313D003810F3 /* VerticalPaymentMethodListViewControllerTest.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = VerticalPaymentMethodListViewControllerTest.swift; sourceTree = "<group>"; };
 		B63B2CF22BFBEE7B003810F3 /* VerticalPaymentMethodListViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = VerticalPaymentMethodListViewController.swift; sourceTree = "<group>"; };
 		B63B2CF42BFBEEAD003810F3 /* PaymentMethodFormViewController.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = PaymentMethodFormViewController.swift; sourceTree = "<group>"; };
@@ -1408,6 +1410,7 @@
 				3F70E5F0FE6218715432D55A /* AddPaymentMethodViewControllerSnapshotTests.swift */,
 				25AB69CF78A2B13839EB32EC /* AddressViewController */,
 				BE92D55DA4B4D449734B2917 /* BacsDDMandateViewSnapshotTests.swift */,
+				B62934F12CAE0ACC009F7C8F /* CardSectionElementTest.swift */,
 				0C53358C028E528F0FC626A2 /* CustomerSheet */,
 				989C2E3E03E42DA64A2FAE0D /* CustomerSheetSnapshotTests.swift */,
 				31699A822BE183D40048677F /* DownloadManagerTest.swift */,
@@ -1750,6 +1753,7 @@
 				4A1A0A542B824C830A200BE0 /* StubbedBackend.swift in Sources */,
 				6151DDC02B14FDCF00ED4F7E /* UpdateCardViewControllerSnapshotTests.swift in Sources */,
 				34CF08CBC636F596B8BA4C12 /* TextFieldElement+CardTest.swift in Sources */,
+				B62934F22CAE0ACC009F7C8F /* CardSectionElementTest.swift in Sources */,
 				52B734BA0B91706F37025523 /* STPAnalyticsClient+PaymentSheetTests.swift in Sources */,
 				AE8EF3966E7BABDFC3B426ED /* PaymentSheet+DashboardConfirmParamsTest.swift in Sources */,
 				B65B42972C013DED00EC565D /* PaymentMethodFormViewControllerTest.swift in Sources */,

StripePaymentSheet/StripePaymentSheet/Source/Internal/Link/Elements/InlineSignup/LinkInlineSignupElement.swift

@@ -9,10 +9,11 @@
 @_spi(STP) import StripeUICore
 import UIKit
 
-final class LinkInlineSignupElement: Element {
+// TODO: Refactor this to be a ContainerElement and contain its sub-elements.
+final class LinkInlineSignupElement: PaymentMethodElement {
     let collectsUserInput: Bool = true
 
-    private let signupView: LinkInlineSignupView
+    let signupView: LinkInlineSignupView
 
     lazy var view: UIView = {
 
@@ -39,12 +40,14 @@ final class LinkInlineSignupElement: Element {
         configuration: PaymentSheet.Configuration,
         linkAccount: PaymentSheetLinkAccount?,
         country: String?,
-        showCheckbox: Bool
+        showCheckbox: Bool,
+        previousCustomerInput: IntentConfirmParams?
     ) {
         self.init(viewModel: LinkInlineSignupViewModel(
             configuration: configuration,
             showCheckbox: showCheckbox,
             accountService: LinkAccountService(apiClient: configuration.apiClient),
+            previousCustomerInput: previousCustomerInput?.linkInlineSignupCustomerInput,
             linkAccount: linkAccount,
             country: country
         ))
@@ -55,6 +58,15 @@ final class LinkInlineSignupElement: Element {
         self.signupView.delegate = self
     }
 
+    func updateParams(params: IntentConfirmParams) -> IntentConfirmParams? {
+        params.linkInlineSignupCustomerInput = .init(
+            phoneNumber: signupView.phoneNumberElement.phoneNumber,
+            name: signupView.nameElement.text,
+            email: signupView.emailElement.emailAddressString,
+            checkboxSelected: signupView.checkboxElement.isChecked
+        )
+        return params
+    }
 }
 
 extension LinkInlineSignupElement: LinkInlineSignupViewDelegate {

StripePaymentSheet/StripePaymentSheet/Source/Internal/Link/Elements/InlineSignup/LinkInlineSignupView-CheckboxElement.swift

@@ -21,6 +21,7 @@ extension LinkInlineSignupView {
         private let appearance: PaymentSheet.Appearance
         /// Controls the stroke color of the checkbox
         private let borderColor: UIColor
+        let initialIsSelectedValue: Bool
 
         var view: UIView {
             return checkboxButton
@@ -56,15 +57,16 @@ extension LinkInlineSignupView {
 
             let checkbox = CheckboxButton(text: text, description: description, theme: appearanceCopy.asElementsTheme)
             checkbox.addTarget(self, action: #selector(didToggleCheckbox), for: .touchUpInside)
-            checkbox.isSelected = false
+            checkbox.isSelected = initialIsSelectedValue
 
             return checkbox
         }()
 
-        init(merchantName: String, appearance: PaymentSheet.Appearance, borderColor: UIColor) {
+        init(merchantName: String, appearance: PaymentSheet.Appearance, borderColor: UIColor, isSelected: Bool) {
             self.merchantName = merchantName
             self.appearance = appearance
             self.borderColor = borderColor
+            self.initialIsSelectedValue = isSelected
         }
 
         func setUserInteraction(isUserInteractionEnabled: Bool) {

StripePaymentSheet/StripePaymentSheet/Source/Internal/Link/Elements/InlineSignup/LinkInlineSignupView.swift

@@ -31,11 +31,12 @@ final class LinkInlineSignupView: UIView {
     private(set) lazy var checkboxElement = CheckboxElement(
         merchantName: viewModel.configuration.merchantDisplayName,
         appearance: viewModel.configuration.appearance,
-        borderColor: borderColor
+        borderColor: borderColor,
+        isSelected: viewModel.saveCheckboxChecked
     )
 
     private(set) lazy var emailElement: LinkEmailElement = {
-        let element = LinkEmailElement(defaultValue: viewModel.emailAddress,
+        let element = LinkEmailElement(defaultValue: viewModel.initialEmail ?? viewModel.emailAddress,
                                        isOptional: viewModel.isEmailOptional,
                                        showLogo: viewModel.mode != .textFieldsOnlyPhoneFirst,
                                        theme: theme)
@@ -44,7 +45,7 @@ final class LinkInlineSignupView: UIView {
     }()
 
     private(set) lazy var nameElement: TextFieldElement = {
-        let configuration = TextFieldElement.NameConfiguration(type: .full, defaultValue: viewModel.legalName)
+        let configuration = TextFieldElement.NameConfiguration(type: .full, defaultValue: viewModel.initialName ?? viewModel.legalName)
         return TextFieldElement(configuration: configuration, theme: theme)
     }()
 
@@ -53,15 +54,28 @@ final class LinkInlineSignupView: UIView {
         // Otherwise, we'd imply consumer consent when it hasn't occurred.
         switch viewModel.mode {
         case .checkbox:
+            let defaultCountryCode = viewModel.initialPhoneNumber?.countryCode ?? viewModel.configuration.defaultBillingDetails.address.country
+            let defaultPhoneNumber = viewModel.initialPhoneNumber?.number ?? viewModel.configuration.defaultBillingDetails.phone
             return PhoneNumberElement(
-                defaultCountryCode: viewModel.configuration.defaultBillingDetails.address.country,
-                defaultPhoneNumber: viewModel.configuration.defaultBillingDetails.phone,
+                defaultCountryCode: defaultCountryCode,
+                defaultPhoneNumber: defaultPhoneNumber,
                 theme: theme
         )
         case .textFieldsOnlyEmailFirst:
-            return PhoneNumberElement(isOptional: viewModel.isPhoneNumberOptional, theme: theme)
+            return PhoneNumberElement(
+                defaultCountryCode: viewModel.initialPhoneNumber?.countryCode,
+                defaultPhoneNumber: viewModel.initialPhoneNumber?.number,
+                isOptional: viewModel.isPhoneNumberOptional,
+                theme: theme
+            )
         case .textFieldsOnlyPhoneFirst:
-            return PhoneNumberElement(isOptional: viewModel.isPhoneNumberOptional, infoView: LinkMoreInfoView(), theme: theme)
+            return PhoneNumberElement(
+                defaultCountryCode: viewModel.initialPhoneNumber?.countryCode,
+                defaultPhoneNumber: viewModel.initialPhoneNumber?.number,
+                isOptional: viewModel.isPhoneNumberOptional,
+                infoView: LinkMoreInfoView(),
+                theme: theme
+            )
         }
     }()
 

StripePaymentSheet/StripePaymentSheet/Source/Internal/Link/Elements/LinkEmailElement.swift

@@ -14,7 +14,7 @@ class LinkEmailElement: Element {
 
     weak var delegate: ElementDelegate?
 
-    private let emailAddressElement: TextFieldElement
+    let emailAddressElement: TextFieldElement
 
     private let activityIndicator: ActivityIndicator = {
         // TODO: Consider adding the activity indicator to TextFieldView

StripePaymentSheet/StripePaymentSheet/Source/Internal/Link/ViewModels/LinkInlineSignupViewModel.swift

@@ -15,6 +15,13 @@ protocol LinkInlineSignupViewModelDelegate: AnyObject {
     func signupViewModelDidUpdate(_ viewModel: LinkInlineSignupViewModel)
 }
 
+struct LinkInlineSignupCustomerInput: Equatable {
+    let phoneNumber: PhoneNumber?
+    let name: String?
+    let email: String?
+    let checkboxSelected: Bool?
+}
+
 final class LinkInlineSignupViewModel {
     enum Action: Equatable {
         case signupAndPay(account: PaymentSheetLinkAccount, phoneNumber: PhoneNumber, legalName: String?)
@@ -38,8 +45,11 @@ final class LinkInlineSignupViewModel {
     let configuration: PaymentSheet.Configuration
 
     let mode: Mode
+    let initialEmail: String?
+    let initialPhoneNumber: PhoneNumber?
+    let initialName: String?
 
-    var saveCheckboxChecked: Bool = false {
+    var saveCheckboxChecked: Bool {
         didSet {
             if saveCheckboxChecked != oldValue {
                 notifyUpdate()
@@ -291,13 +301,18 @@ final class LinkInlineSignupViewModel {
         configuration: PaymentSheet.Configuration,
         showCheckbox: Bool,
         accountService: LinkAccountServiceProtocol,
+        previousCustomerInput: LinkInlineSignupCustomerInput?,
         linkAccount: PaymentSheetLinkAccount? = nil,
         country: String? = nil
     ) {
         self.configuration = configuration
         self.accountService = accountService
         self.linkAccount = linkAccount
         self.emailAddress = linkAccount?.email
+        self.saveCheckboxChecked = previousCustomerInput?.checkboxSelected ?? false
+        self.initialEmail = previousCustomerInput?.email
+        self.initialPhoneNumber = previousCustomerInput?.phoneNumber
+        self.initialName = previousCustomerInput?.name
         if let email = self.emailAddress,
            !email.isEmpty {
             emailWasPrefilled = true

StripePaymentSheet/StripePaymentSheet/Source/PaymentSheet/IntentConfirmParams.swift

@@ -36,6 +36,8 @@ final class IntentConfirmParams {
 
     var financialConnectionsLinkedBank: FinancialConnectionsLinkedBank?
     var instantDebitsLinkedBank: InstantDebitsLinkedBank?
+    /// Hack: Contains the customer input in the link inline signup element (e.g. email, checkbox state) so that it can be preserved across `FlowController.update` etc.
+    var linkInlineSignupCustomerInput: LinkInlineSignupCustomerInput?
 
     var paymentSheetLabel: String {
         if let last4 = (financialConnectionsLinkedBank?.last4 ?? instantDebitsLinkedBank?.last4) {

StripePaymentSheet/StripePaymentSheet/Source/PaymentSheet/PaymentSheetFormFactory/PaymentSheetFormFactory+Card.swift

@@ -93,7 +93,8 @@ extension PaymentSheetFormFactory {
                 configuration: configuration,
                 linkAccount: linkAccount,
                 country: countryCode,
-                showCheckbox: !shouldDisplaySaveCheckbox
+                showCheckbox: !shouldDisplaySaveCheckbox,
+                previousCustomerInput: previousCustomerInput
             )
             elements.append(inlineSignupElement)
         }

StripePaymentSheet/StripePaymentSheetTests/PaymentSheet/CardSectionElementTest.swift

@@ -0,0 +1,93 @@
+//
+//  CardSectionElementTest.swift
+//  StripePaymentSheetTests
+//
+//  Created by Yuki Tokuhiro on 10/2/24.
+//
+
+@testable@_spi(STP) import StripeCore
+@testable@_spi(STP) import StripePayments
+@testable@_spi(STP) import StripePaymentSheet
+@testable@_spi(STP) import StripePaymentsTestUtils
+@testable@_spi(STP) import StripePaymentsUI
+@testable@_spi(STP) import StripeUICore
+import XCTest
+
+@MainActor
+final class CardSectionElementTest: XCTestCase {
+    let window: UIWindow = UIWindow(frame: .init(x: 0, y: 0, width: 428, height: 926))
+
+    func testLinkSignupPreservesPreviousCustomerInput() async {
+        await PaymentSheetLoader.loadMiscellaneousSingletons()
+        func makeForm(previousCustomerInput: IntentConfirmParams?) -> PaymentMethodElement {
+            let intent: Intent = ._testPaymentIntent(paymentMethodTypes: [.card])
+            let formVC = PaymentMethodFormViewController(
+                type: .stripe(.card),
+                intent: intent,
+                elementsSession: ._testValue(paymentMethodTypes: ["card"], isLinkPassthroughModeEnabled: true),
+                previousCustomerInput: previousCustomerInput,
+                formCache: .init(),
+                configuration: .init(),
+                headerView: nil,
+                analyticsHelper: ._testValue(),
+                delegate: self
+            )
+
+            // Add to window to avoid layout errors due to zero size and presentation errors
+            window.rootViewController = formVC
+
+            // Simulate view appearance. This makes SimpleMandateElement mark its mandate as having been displayed.
+            formVC.viewDidAppear(false)
+            return formVC.form
+        }
+        let form = makeForm(previousCustomerInput: nil)
+        let linkInlineSignupElement: LinkInlineSignupElement = form.getElement()!
+        let linkInlineView = linkInlineSignupElement.signupView
+        XCTAssertNotNil(linkInlineView.checkboxElement) // Checkbox should appear since this is a PI w/o customer
+        form.getTextFieldElement("Card number")?.setText("4242424242424242")
+        form.getTextFieldElement("MM / YY").setText("1232")
+        form.getTextFieldElement("CVC").setText("123")
+        form.getTextFieldElement("ZIP").setText("65432")
+
+        // Simulate selecting checkbox
+        linkInlineView.checkboxElement.isChecked = true
+        linkInlineView.checkboxElement.didToggleCheckbox()
+
+        // Set the email & phone number
+        let email = "\(UUID().uuidString)@foo.com"
+        linkInlineView.emailElement.emailAddressElement.setText(email)
+        linkInlineView.phoneNumberElement.countryDropdownElement.setRawData("GB")
+        linkInlineView.phoneNumberElement.textFieldElement.setText("1234567890")
+        linkInlineView.nameElement.setText("John Doe")
+
+        // Generate params from the form
+        guard let intentConfirmParams = form.updateParams(params: IntentConfirmParams(type: .stripe(.card))) else {
+            XCTFail("Form failed to create params. Validation state: \(form.validationState) \n Form: \(form)")
+            return
+        }
+
+        // Re-generate the form and validate that it carries over all previous customer input
+        let regeneratedForm = makeForm(previousCustomerInput: intentConfirmParams)
+        let regeneratedLinkInlineSignupElement: LinkInlineSignupElement = regeneratedForm.getElement()!
+        let regeneratedLinkInlineView = linkInlineSignupElement.signupView
+        guard let regeneratedIntentConfirmParams = regeneratedForm.updateParams(params: IntentConfirmParams(type: .stripe(.card))) else {
+            XCTFail("Regenerated form failed to create params. Validation state: \(regeneratedForm.validationState) \n Form: \(regeneratedForm)")
+            return
+        }
+        XCTAssertEqual(regeneratedIntentConfirmParams, intentConfirmParams)
+        XCTAssertTrue(regeneratedLinkInlineSignupElement.isChecked)
+        XCTAssertEqual(regeneratedLinkInlineView.emailElement.emailAddressString, email)
+        XCTAssertEqual(regeneratedLinkInlineView.nameElement.text, "John Doe")
+        XCTAssertEqual(regeneratedLinkInlineView.phoneNumberElement.phoneNumber, PhoneNumber(number: "1234567890", countryCode: "GB"))
+    }
+}
+
+extension CardSectionElementTest: PaymentMethodFormViewControllerDelegate {
+    func didUpdate(_ viewController: StripePaymentSheet.PaymentMethodFormViewController) {
+
+    }
+
+    func updateErrorLabel(for error: (any Error)?) {
+
+    }
+}

StripePaymentSheet/StripePaymentSheetTests/PaymentSheet/PaymentSheetLPMConfirmFlowTests.swift

@@ -979,11 +979,15 @@ extension IntentConfirmParams: Equatable {
             print("Instant debits linked banks not equal: \(lhs.instantDebitsLinkedBank.debugDescription) vs \(rhs.instantDebitsLinkedBank.debugDescription)")
             return false
         }
+        if lhs.linkInlineSignupCustomerInput != rhs.linkInlineSignupCustomerInput {
+            print("Link inline signup customer input not equal: \(lhs.linkInlineSignupCustomerInput.debugDescription) vs \(rhs.linkInlineSignupCustomerInput.debugDescription)")
+            return false
+        }
 
         // Sanity check to make sure when we add new properties, we check them here
         let mirror = Mirror(reflecting: lhs)
         let propertyCount = mirror.children.count
-        XCTAssertEqual(propertyCount, 7)
+        XCTAssertEqual(propertyCount, 8)
 
         return true
     }