Attempt to deflake testCreate_britishAccount_klarna_withLegalDisclosure by resetting singleton

StripePaymentSheet/StripePaymentSheetTests/PaymentSheet/Link/LinkInlineVerificationViewSnapshotTests.swift

@@ -14,6 +14,18 @@ import UIKit
 @MainActor
 class LinkInlineVerificationViewSnapshotTests: STPSnapshotTestCase {
     private let frame = CGRect(x: 0, y: 0, width: 328, height: 328)
+    private var testWindow: UIWindow?
+
+    override func tearDown() {
+        // CRITICAL: Properly dismiss and nil out the test window to ensure
+        // any SwiftUI views and their async Tasks are cleaned up before the next test runs.
+        // Without this, the LinkInlineVerificationView's .onAppear Task can still be running
+        // and attempt to call start_verification, causing flaky test failures.
+        testWindow?.rootViewController = nil
+        testWindow?.isHidden = true
+        testWindow = nil
+        super.tearDown()
+    }
 
     @available(iOS 16.0, *)
     func testLinkInlineVerificationView_NoPaymentMethodPreview() {
@@ -32,9 +44,9 @@ class LinkInlineVerificationViewSnapshotTests: STPSnapshotTestCase {
         let vc = UIHostingController(rootView: verificationView)
 
         // Need to host the SwiftUI view in a window for iOSSnapshotTestCase to work:
-        let window = UIWindow(frame: frame)
-        window.rootViewController = vc
-        window.makeKeyAndVisible()
+        testWindow = UIWindow(frame: frame)
+        testWindow?.rootViewController = vc
+        testWindow?.makeKeyAndVisible()
 
         STPSnapshotVerifyView(vc.view, identifier: nil, file: #filePath, line: #line)
     }
@@ -62,9 +74,9 @@ class LinkInlineVerificationViewSnapshotTests: STPSnapshotTestCase {
         let vc = UIHostingController(rootView: verificationView)
 
         // Need to host the SwiftUI view in a window for iOSSnapshotTestCase to work:
-        let window = UIWindow(frame: frame)
-        window.rootViewController = vc
-        window.makeKeyAndVisible()
+        testWindow = UIWindow(frame: frame)
+        testWindow?.rootViewController = vc
+        testWindow?.makeKeyAndVisible()
 
         STPSnapshotVerifyView(vc.view, identifier: nil, file: #filePath, line: #line)
     }
@@ -92,9 +104,9 @@ class LinkInlineVerificationViewSnapshotTests: STPSnapshotTestCase {
         let vc = UIHostingController(rootView: verificationView)
 
         // Need to host the SwiftUI view in a window for iOSSnapshotTestCase to work:
-        let window = UIWindow(frame: frame)
-        window.rootViewController = vc
-        window.makeKeyAndVisible()
+        testWindow = UIWindow(frame: frame)
+        testWindow?.rootViewController = vc
+        testWindow?.makeKeyAndVisible()
 
         STPSnapshotVerifyView(vc.view, identifier: nil, file: #filePath, line: #line)
     }

StripePaymentSheet/StripePaymentSheetTests/PaymentSheet/PMMENetworkInitializationTests.swift

@@ -28,6 +28,32 @@ class PMMENetworkInitializationTests: STPNetworkStubbingTestCase {
     override func setUp() {
         super.setUp()
 
+        // CRITICAL: Clear the global default publishable key that other tests may have set
+        // This is a static global that persists across test runs and can cause unexpected behavior
+        // when creating new STPAPIClient instances
+        StripeAPI.defaultPublishableKey = nil
+
+        // Clear Link account context that might be set by previous tests
+        LinkAccountContext.shared.account = nil
+
+        // Clear any persisted Link-related UserDefaults that might trigger unexpected behavior
+        UserDefaults.standard.clearLinkDefaults()
+        UserDefaults.standard.customerToLastSelectedPaymentMethod = nil
+
+        // Clear any persisted attestation state in UserDefaults that might trigger unexpected network calls
+        // StripeAttest stores state keyed by publishable key - this stale state from previous test runs
+        // can cause unexpected /v1/consumers/sessions/start_verification calls
+        for key in [Self.usPublishableKey, Self.frenchPublishableKey, Self.britishPublishableKey, "pk_test_123", "pk_test_123456789"] {
+            let keysToRemove = ["keyID", "successfullyAttested", "dailyAttemptCount", "firstAttemptToday"].map { "\($0):\(key)" }
+            keysToRemove.forEach { UserDefaults.standard.removeObject(forKey: $0) }
+        }
+
+        // CRITICAL: Clear HTTP cookies and cache from shared URLSession configuration
+        // These persist between test suite runs and can cause flaky tests!
+        // Specifically, Link session cookies from previous tests can trigger unexpected consumer session calls
+        HTTPCookieStorage.shared.removeCookies(since: Date.distantPast)
+        URLCache.shared.removeAllCachedResponses()
+
         // Create a DownloadManager with the shared URLSession configuration
         // This allows the network stubbing recorder to intercept API requests
         let urlSessionConfig = StripeAPIConfiguration.sharedUrlSessionConfiguration

StripePaymentSheet/StripePaymentSheetTests/PaymentSheet/PaymentSheet+PaymentMethodAvailabilityTest.swift

@@ -135,6 +135,7 @@ final class PaymentMethodAvailabilityTest: XCTestCase {
 
         STPAPIClient.shared.publishableKey = originalPublishableKey
         XCTAssertTrue(isLinkSignupEnabled, "Link inline signup should be enabled for linkSignupOptInFeatureEnabled even if general signup disabled")
+        LinkAccountContext.shared.account = nil
     }
 
     func testIsLinkSignupEnabled_enabled_for_linkSignupOptInFeatureEnabled_if_email_provided() {
@@ -153,6 +154,7 @@ final class PaymentMethodAvailabilityTest: XCTestCase {
 
         STPAPIClient.shared.publishableKey = originalPublishableKey
         XCTAssertTrue(isLinkSignupEnabled, "Link inline signup should be enabled for linkSignupOptInFeatureEnabled if an email was provided")
+        LinkAccountContext.shared.account = nil
     }
 
     func testIsLinkSignupEnabled_disabled_for_linkSignupOptInFeatureEnabled_if_no_email_provided() {