Fix embedded update preserving invalid paymentoption (#4189)

## Summary
Previously, embedded would always preserve the selected payment option
across `update`, even if it's no longer valid. This PR fixes that.

Also contains some minor unrelated tweaks.

## Testing
See test

## Changelog
Not user facing

Example/PaymentSheet Example/PaymentSheet Example-Shard1.xctestplan

@@ -31,6 +31,8 @@
     {
       "parallelizable" : true,
       "skippedTests" : [
+        "EmbeddedUITests",
+        "EmbeddedUITests\/testUpdate()",
         "PaymentSheetBillingCollectionLPMUITests",
         "PaymentSheetBillingCollectionUICardTests",
         "PaymentSheetBillingCollectionUITestCase",

Example/PaymentSheet Example/PaymentSheet Example-Shard2.xctestplan

@@ -33,6 +33,8 @@
       "skippedTests" : [
         "CustomerSheetSnapshotTests",
         "CustomerSheetUITest",
+        "EmbeddedUITests",
+        "EmbeddedUITests\/testUpdate()",
         "LinkPaymentControllerUITest",
         "PaymentSheetBillingCollectionBankTests",
         "PaymentSheetBillingCollectionLPMUITests",

Example/PaymentSheet Example/PaymentSheet Example-Shard3.xctestplan

@@ -33,6 +33,8 @@
       "skippedTests" : [
         "CustomerSheetSnapshotTests",
         "CustomerSheetUITest",
+        "EmbeddedUITests",
+        "EmbeddedUITests\/testUpdate()",
         "LinkPaymentControllerUITest",
         "PaymentSheetBillingCollectionBankTests",
         "PaymentSheetCVCRecollectionUITests",

Example/PaymentSheet Example/PaymentSheet Example.xcodeproj/project.pbxproj

@@ -55,6 +55,7 @@
 		B641A4192C2BA25D00AE654A /* PaymentSheetVerticalUITest.swift in Sources */ = {isa = PBXBuildFile; fileRef = B641A4182C2BA25D00AE654A /* PaymentSheetVerticalUITest.swift */; };
 		B6CA975C2C486DE700DAE441 /* PaymentSheetLPMUITest.swift in Sources */ = {isa = PBXBuildFile; fileRef = B6CA975B2C486DE700DAE441 /* PaymentSheetLPMUITest.swift */; };
 		B6D6AAA666859847BB59749C /* PaymentSheet+AddressTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = A61C5739DBE6405A4D9FD5F2 /* PaymentSheet+AddressTests.swift */; };
+		B6DA0FEE2CC97F4900BF41B7 /* EmbeddedUITest.swift in Sources */ = {isa = PBXBuildFile; fileRef = B6DA0FED2CC97F3D00BF41B7 /* EmbeddedUITest.swift */; };
 		C39CA2EBE08EE768559A8FD1 /* StripeCore.framework in Embed Frameworks */ = {isa = PBXBuildFile; fileRef = 1FD1F5193E4A361EA9E8FED3 /* StripeCore.framework */; settings = {ATTRIBUTES = (CodeSignOnCopy, RemoveHeadersOnCopy, ); }; };
 		CC9090D573972E8B14D204CB /* CustomerSheetTestPlaygroundSettings.swift in Sources */ = {isa = PBXBuildFile; fileRef = F2F10B63B9ECBC62AFCF8B32 /* CustomerSheetTestPlaygroundSettings.swift */; };
 		D235E82A7173E8051BC5A261 /* ExampleCustomCheckoutViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = ECF244A593BD92A973B1C369 /* ExampleCustomCheckoutViewController.swift */; };
@@ -249,6 +250,7 @@
 		B641A4182C2BA25D00AE654A /* PaymentSheetVerticalUITest.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PaymentSheetVerticalUITest.swift; sourceTree = "<group>"; };
 		B69C155A2B9FDCBD009CE667 /* PaymentSheet Example.entitlements */ = {isa = PBXFileReference; lastKnownFileType = text.plist.entitlements; name = "PaymentSheet Example.entitlements"; path = "PaymentSheet Example/PaymentSheet Example.entitlements"; sourceTree = "<group>"; };
 		B6CA975B2C486DE700DAE441 /* PaymentSheetLPMUITest.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PaymentSheetLPMUITest.swift; sourceTree = "<group>"; };
+		B6DA0FED2CC97F3D00BF41B7 /* EmbeddedUITest.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = EmbeddedUITest.swift; sourceTree = "<group>"; };
 		B7AFD32B5EAD3BEEEC3D4260 /* ExampleSwiftUIPaymentSheet.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ExampleSwiftUIPaymentSheet.swift; sourceTree = "<group>"; };
 		B7C76D3D1BF7666D1963DD0B /* bg-BG */ = {isa = PBXFileReference; lastKnownFileType = text.plist.strings; name = "bg-BG"; path = "bg-BG.lproj/LaunchScreen.strings"; sourceTree = "<group>"; };
 		B96951DD278BA611BBCBB10A /* PaymentSheet Example-Shard1.xctestplan */ = {isa = PBXFileReference; lastKnownFileType = text; path = "PaymentSheet Example-Shard1.xctestplan"; sourceTree = "<group>"; };
@@ -422,6 +424,7 @@
 				5CA299EAF5914484195167EB /* PaymentSheetUITest.swift */,
 				B6CA975B2C486DE700DAE441 /* PaymentSheetLPMUITest.swift */,
 				B641A4182C2BA25D00AE654A /* PaymentSheetVerticalUITest.swift */,
+				B6DA0FED2CC97F3D00BF41B7 /* EmbeddedUITest.swift */,
 				36BB679CF53EEF943F0BAAC9 /* XCUITest+Utilities.swift */,
 				6A5CCDA32C0E6F5D003306A4 /* LinkPaymentControllerUITest.swift */,
 			);
@@ -657,6 +660,7 @@
 			isa = PBXSourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				B6DA0FEE2CC97F4900BF41B7 /* EmbeddedUITest.swift in Sources */,
 				5441EB34BBE32DD98B7A6883 /* CustomerSheetTestPlaygroundSettings.swift in Sources */,
 				E66F4E053FC6DD05EA245CDF /* CustomerSheetUITest.swift in Sources */,
 				B6CA975C2C486DE700DAE441 /* PaymentSheetLPMUITest.swift in Sources */,

Example/PaymentSheet Example/PaymentSheet Example/EmbeddedPlaygroundViewController.swift

@@ -189,6 +189,7 @@ private class EmbeddedPaymentOptionView: UIView {
         label.font = .preferredFont(forTextStyle: .subheadline)
         label.numberOfLines = 1
         label.translatesAutoresizingMaskIntoConstraints = false
+        label.accessibilityIdentifier = "Payment method"
         return label
     }()
 

Example/PaymentSheet Example/PaymentSheet Example/PlaygroundController.swift

@@ -731,7 +731,6 @@ extension PlaygroundController {
                 case .embedded:
                     guard !shouldUpdateEmbeddedInsteadOfRecreating else {
                         // Update embedded rather than re-creating it
-                        self.embeddedPlaygroundViewController?.isLoading = false
                         self.updateEmbedded()
                         self.currentlyRenderedSettings = self.settings
                         return
@@ -979,6 +978,7 @@ extension PlaygroundController {
                 break
             case .failed(let error):
                 // Display error to user in an alert, let them retry
+                self.embeddedPlaygroundViewController?.isLoading = false
                 let alert = UIAlertController(title: "Error", message: error.localizedDescription, preferredStyle: .alert)
                 alert.addAction(.init(title: "Retry", style: .default, handler: { _ in
                     self.updateEmbedded()
@@ -987,6 +987,7 @@ extension PlaygroundController {
                 embeddedPlaygroundViewController.present(alert, animated: true)
             case .succeeded:
                 self.isLoading = false
+                self.embeddedPlaygroundViewController?.isLoading = false
             }
         }
     }

Example/PaymentSheet Example/PaymentSheetUITest/EmbeddedUITest.swift

@@ -0,0 +1,31 @@
+//
+//  EmbeddedUITest.swift
+//  PaymentSheet Example
+//
+//  Created by Yuki Tokuhiro on 10/23/24.
+//
+
+import XCTest
+
+class EmbeddedUITests: PaymentSheetUITestCase {
+    func testUpdate() {
+        var settings = PaymentSheetTestPlaygroundSettings.defaultValues()
+        settings.customerMode = .new
+        settings.mode = .payment
+        settings.integrationType = .deferred_csc
+        settings.uiStyle = .embedded
+        loadPlayground(app, settings)
+        app.buttons["Present embedded payment element"].waitForExistenceAndTap()
+        // TODO: Test card form (see PaymentSheetVerticalUITests testUpdate)
+
+        // Selecting Alipay w/ deferred PaymentIntent...
+        app.buttons["Alipay"].waitForExistenceAndTap()
+        XCTAssertEqual(app.staticTexts["Payment method"].label, "Alipay")
+        // ...and *updating* to a SetupIntent...
+        app.buttons.matching(identifier: "Setup").element(boundBy: 1).tap()
+        // ...(wait for it to finish updating)...
+        _ = app.buttons["Reload"].waitForExistence(timeout: 10)
+        // ...should cause Alipay to no longer be the selected payment method, since it is not valid for setup.
+        XCTAssertFalse(app.staticTexts["Payment method"].exists)
+    }
+}

StripePaymentSheet/StripePaymentSheet/Source/PaymentSheet/Embedded/EmbeddedPaymentElement.swift

@@ -105,8 +105,8 @@ public final class EmbeddedPaymentElement {
     ) async -> UpdateResult {
         embeddedPaymentMethodsView.isUserInteractionEnabled = false
         // Cancel the old task and let it finish so that merchants receive update results in order
-        currentUpdateTask?.cancel()
-        _ = await currentUpdateTask?.value
+        latestUpdateTask?.cancel()
+        _ = await latestUpdateTask?.value
         // Start the new update task
         let currentUpdateTask = Task { @MainActor [weak self, configuration, analyticsHelper] in
             // ⚠️ Don't modify `self` until the end to avoid being canceled halfway through and leaving self in a partially updated state.
@@ -158,7 +158,7 @@ public final class EmbeddedPaymentElement {
             }
             return .succeeded
         }
-        self.currentUpdateTask = currentUpdateTask
+        self.latestUpdateTask = currentUpdateTask
         let updateResult = await currentUpdateTask.value
         embeddedPaymentMethodsView.isUserInteractionEnabled = true
         return updateResult
@@ -170,8 +170,8 @@ public final class EmbeddedPaymentElement {
     /// - Note: This method requires that the last call to `update` succeeded. If the last `update` call failed, this call will fail. If this method is called while a call to `update` is in progress, it waits until the `update` call completes.
     public func confirm() async -> EmbeddedPaymentElementResult {
         // Wait for the last update to finish and fail if didn't succeed. A failure means the view is out of sync with the intent and could e.g. not be showing a required mandate.
-        if let currentUpdateTask {
-            switch await currentUpdateTask.value {
+        if let latestUpdateTask {
+            switch await latestUpdateTask.value {
             case .succeeded:
                 // The view is in sync with the intent. Continue on with confirm!
                 break
@@ -194,7 +194,7 @@ public final class EmbeddedPaymentElement {
     internal private(set) var containerView: EmbeddedPaymentElementContainerView
     internal private(set) var embeddedPaymentMethodsView: EmbeddedPaymentMethodsView
     internal private(set) var loadResult: PaymentSheetLoader.LoadResult
-    internal private(set) var currentUpdateTask: Task<UpdateResult, Never>?
+    internal private(set) var latestUpdateTask: Task<UpdateResult, Never>?
     private let analyticsHelper: PaymentSheetAnalyticsHelper
     internal var _paymentOption: PaymentOption? {
         // TODO: Handle forms. See `PaymentSheetVerticalViewController.selectedPaymentOption`.

StripePaymentSheet/StripePaymentSheet/Source/PaymentSheet/Embedded/EmbeddedPaymentMethodsView.swift

@@ -61,7 +61,6 @@ class EmbeddedPaymentMethodsView: UIView {
         delegate: EmbeddedPaymentMethodsViewDelegate? = nil
     ) {
         self.appearance = appearance
-        self.selection = initialSelection
         self.mandateProvider = mandateProvider
         self.shouldShowMandate = shouldShowMandate
         self.delegate = delegate
@@ -90,21 +89,30 @@ class EmbeddedPaymentMethodsView: UIView {
 
             if initialSelection == selection {
                 savedPaymentMethodButton.isSelected = true
+                self.selection = initialSelection
             }
 
             stackView.addArrangedSubview(savedPaymentMethodButton)
         }
 
         // Add card before Apple Pay and Link if present and before any other LPMs
         if paymentMethodTypes.contains(.stripe(.card)) {
-            stackView.addArrangedSubview(RowButton.makeForPaymentMethodType(paymentMethodType: .stripe(.card),
-                                                                            savedPaymentMethodType: savedPaymentMethod?.type,
-                                                                            appearance: rowButtonAppearance,
-                                                                            shouldAnimateOnPress: true,
-                                                                            isEmbedded: true,
-                                                                            didTap: { [weak self] rowButton in
-                self?.didTap(selectedRowButton: rowButton, selection: .new(paymentMethodType: .stripe(.card)))
-            }))
+            let selection: Selection = .new(paymentMethodType: .stripe(.card))
+            let cardRowButton = RowButton.makeForPaymentMethodType(
+                paymentMethodType: .stripe(.card),
+                savedPaymentMethodType: savedPaymentMethod?.type,
+                appearance: rowButtonAppearance,
+                shouldAnimateOnPress: true,
+                isEmbedded: true,
+                didTap: { [weak self] rowButton in
+                    self?.didTap(selectedRowButton: rowButton, selection: selection)
+                }
+            )
+            if initialSelection == selection {
+                cardRowButton.isSelected = true
+                self.selection = initialSelection
+            }
+            stackView.addArrangedSubview(cardRowButton)
         }
 
         if shouldShowApplePay {
@@ -117,6 +125,7 @@ class EmbeddedPaymentMethodsView: UIView {
 
             if initialSelection == selection {
                 applePayRowButton.isSelected = true
+                self.selection = initialSelection
             }
 
             stackView.addArrangedSubview(applePayRowButton)
@@ -130,6 +139,7 @@ class EmbeddedPaymentMethodsView: UIView {
 
             if initialSelection == selection {
                 linkRowButton.isSelected = true
+                self.selection = initialSelection
             }
 
             stackView.addArrangedSubview(linkRowButton)
@@ -151,6 +161,7 @@ class EmbeddedPaymentMethodsView: UIView {
             )
             if initialSelection == selection {
                 rowButton.isSelected = true
+                self.selection = initialSelection
             }
             stackView.addArrangedSubview(rowButton)
         }