Fix data race in DependencyContainer.init on plain configure()

CHANGELOG.md

@@ -7,6 +7,7 @@ The changelog for `SuperwallKit`. Also see the [releases](https://github.com/sup
 ### Fixes
 
 - Fixes subscribers with an unexpired subscription being reported as `inactive` on cold launch when the App Store has no purchases to report. Refunded and expired App Store subscriptions still deactivate immediately.
+- Fixes a data race during SDK configuration that Thread Sanitizer flagged on every launch.
 - Fixes issue where paying web users could end up having a temporary inactive subscription status if the server temporarily returns no entitlement data for them.
 
 ## 4.16.3

Sources/SuperwallKit/Superwall.swift

@@ -473,6 +473,11 @@ public final class Superwall: NSObject, ObservableObject {
 
     addListeners()
 
+    // Recover any Stripe checkout that was pending when the app was killed.
+    // Kicked off here rather than inside an initializer so the redeemer's
+    // background poll can only ever see a fully-built dependency container.
+    dependencyContainer.webEntitlementRedeemer.pollPendingStripeCheckoutOnColdLaunch()
+
     // This task runs on a background thread, even if called from a main thread.
     // This is because the function isn't marked to run on the main thread,
     // therefore, we don't need to make this detached.

Sources/SuperwallKit/Web/WebEntitlementRedeemer.swift

@@ -112,12 +112,17 @@ actor WebEntitlementRedeemer {
       name: UIApplication.willEnterForegroundNotification,
       object: nil
     )
+  }
 
-    // Also check once on SDK initialization so pending Stripe checkouts can be
-    // recovered on cold launch. Guard on factory readiness to avoid accessing
-    // dependencies (e.g. deviceHelper) before the container is fully set up.
+  /// Checks once on SDK initialization so pending Stripe checkouts can be
+  /// recovered on cold launch.
+  ///
+  /// Called by `Superwall` after the dependency container is fully built,
+  /// rather than from this actor's own `init`: the poll reads container state
+  /// from a background task, so it must not start while the container is
+  /// still being set up.
+  nonisolated func pollPendingStripeCheckoutOnColdLaunch() {
     Task {
-      guard factory.makeIsContainerReady() else { return }
       await pollPendingStripeCheckoutOnForegroundIfNeeded()
     }
   }

SuperwallKit.xcodeproj/project.pbxproj

@@ -167,6 +167,7 @@
 		4A4E788046CD308F465B37BF /* ProductsFetcherSK2.swift in Sources */ = {isa = PBXBuildFile; fileRef = 57AD390BC73341A49301B4AA /* ProductsFetcherSK2.swift */; };
 		4AA4E2CE223DC7CF1678E83C /* TrackTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 65E23B703C00044332FDEBE8 /* TrackTests.swift */; };
 		4AB907436D4A84932F09D8B3 /* String+MD5.swift in Sources */ = {isa = PBXBuildFile; fileRef = D449672964023589DA5535E3 /* String+MD5.swift */; };
+		4ABF9FB54105917343865145 /* DependencyContainerInitTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 880CE7E95B65A756C372CE05 /* DependencyContainerInitTests.swift */; };
 		4B0E203D477E48611797047C /* PaywallViewControllerCacheTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 672776875A4286319C2F2D61 /* PaywallViewControllerCacheTests.swift */; };
 		4B4BCB32699C3A1AF7E2BFE6 /* SK2StoreProductCyclesTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = B00929DACD8621FC32F83927 /* SK2StoreProductCyclesTests.swift */; };
 		4B54BA9E52A97C486D808A05 /* IntroOfferToken.swift in Sources */ = {isa = PBXBuildFile; fileRef = DEF0596D5BDDE0911046E60D /* IntroOfferToken.swift */; };
@@ -897,6 +898,7 @@
 		8719AC2E83128EE469E58C36 /* RedeemRequest.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = RedeemRequest.swift; sourceTree = "<group>"; };
 		87AD727C5A8639E704F7BE98 /* PaywallView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PaywallView.swift; sourceTree = "<group>"; };
 		87B1E659458AE78C3908562B /* SK2ReceiptManagerTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SK2ReceiptManagerTests.swift; sourceTree = "<group>"; };
+		880CE7E95B65A756C372CE05 /* DependencyContainerInitTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = DependencyContainerInitTests.swift; sourceTree = "<group>"; };
 		884DF3D8A1CA382BFEE9F8F4 /* ArchiveManifestUsage.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ArchiveManifestUsage.swift; sourceTree = "<group>"; };
 		887834329A06971D86D5282F /* NotificationProtocols.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = NotificationProtocols.swift; sourceTree = "<group>"; };
 		88EBF6FC3090E004EE1377B4 /* PaywallViewControllerDelegate.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PaywallViewControllerDelegate.swift; sourceTree = "<group>"; };
@@ -2716,6 +2718,7 @@
 				D554340BB6652F5FA1F21FF8 /* Config */,
 				38C02C19ED9C9958A7A61FB1 /* Debug */,
 				3B16D25FCB6991D55E0F63B3 /* DeepLink */,
+				E9FF04AB866B9CCA7DFBE592 /* Dependencies */,
 				373AFF230833A951B6E5DF36 /* Identity */,
 				8DD7B7C5E111EAB0878886B6 /* Logger */,
 				4D7656D6A565958F58A644AF /* Misc */,
@@ -2822,8 +2825,8 @@
 			children = (
 				0E3AC3B23DAAA8C1D125BDD3 /* CoreDataManager.swift */,
 				50458143450675EF205CE2C3 /* CoreDataStack.swift */,
-				EC51351CA716C5C3B71E2FA1 /* SuperwallKit_Model.xcdatamodeld */,
 				2DAF3427CF469F5373C2BFD7 /* Managed Models */,
+				EC51351CA716C5C3B71E2FA1 /* SuperwallKit_Model.xcdatamodeld */,
 			);
 			path = "Core Data";
 			sourceTree = "<group>";
@@ -2996,6 +2999,14 @@
 			path = Options;
 			sourceTree = "<group>";
 		};
+		E9FF04AB866B9CCA7DFBE592 /* Dependencies */ = {
+			isa = PBXGroup;
+			children = (
+				880CE7E95B65A756C372CE05 /* DependencyContainerInitTests.swift */,
+			);
+			path = Dependencies;
+			sourceTree = "<group>";
+		};
 		ED389E60F716C417202738F0 /* Misc */ = {
 			isa = PBXGroup;
 			children = (
@@ -3173,9 +3184,10 @@
 			attributes = {
 				BuildIndependentTargetsInParallel = YES;
 				LastUpgradeCheck = 1430;
+				TargetAttributes = {
+				};
 			};
 			buildConfigurationList = B7BB212B66F694F1FDA2FA4F /* Build configuration list for PBXProject "SuperwallKit" */;
-			compatibilityVersion = "Xcode 14.0";
 			developmentRegion = en;
 			hasScannedForEncodings = 0;
 			knownRegions = (
@@ -3228,6 +3240,7 @@
 				89F17188BC665EFC6FE5CEFA /* XCRemoteSwiftPackageReference "superscript-ios-next" */,
 			);
 			preferredProjectObjectVersion = 77;
+			productRefGroup = 778C04FFAA9840C37CA3C1CA /* Products */;
 			projectDirPath = "";
 			projectRoot = "";
 			targets = (
@@ -3289,6 +3302,7 @@
 				654803E77F7CDBF6282D0110 /* Date+IsWithinAnHourBeforeTests.swift in Sources */,
 				D91750797BB4947F6975B2B9 /* Date+IsoStringTests.swift in Sources */,
 				01BE837B492223B76A95CB5D /* DeepLinkRouterTests.swift in Sources */,
+				4ABF9FB54105917343865145 /* DependencyContainerInitTests.swift in Sources */,
 				0CA13E721ADB243882536D4A /* DeviceHelperMock.swift in Sources */,
 				9DBDDD10A1EFC7CD3575D9E5 /* DeviceHelperTests.swift in Sources */,
 				2743143ED664F942D5D758B1 /* DevicePreloadScriptTests.swift in Sources */,

Tests/SuperwallKitTests/Dependencies/DependencyContainerInitTests.swift

@@ -0,0 +1,26 @@
+//
+//  DependencyContainerInitTests.swift
+//  SuperwallKit
+//
+//  Created by Yusuf Tör on 25/08/2026.
+//
+
+import Testing
+@testable import SuperwallKit
+import Foundation
+
+struct DependencyContainerInitTests {
+  /// https://github.com/superwall/Superwall-iOS/issues/504
+  ///
+  /// `DependencyContainer.init` used to pass `self` to `WebEntitlementRedeemer`,
+  /// whose init spawned a task reading `configManager` on a background thread
+  /// while init was still assigning stored properties. This loop only signals
+  /// under Thread Sanitizer (`-enableThreadSanitizer YES`), where it reproduced
+  /// the race on the first iteration; without TSan it's a smoke test.
+  @Test("Constructing the container doesn't race against its own init")
+  func containerInitHasNoDataRace() {
+    for _ in 0..<10 {
+      _ = DependencyContainer(apiKey: "pk_test_504")
+    }
+  }
+}

Tests/SuperwallKitTests/Web/WebEntitlementRedeemerTests.swift

@@ -29,7 +29,7 @@ struct WebEntitlementRedeemerTests {
 
   init() {
     // Clear any pending stripe checkout state left on disk by a previous test
-    // to prevent the WebEntitlementRedeemer init Task from triggering unexpected saves.
+    // so foreground/cold-launch polls triggered later can't see stale state.
     dependencyContainer.storage.delete(PendingStripeCheckoutPollStorage.self)
   }
 
@@ -2942,4 +2942,85 @@ struct WebEntitlementRedeemerTests {
     // Failed status clears pending state, but we can verify the poll happened
     #expect(mockNetwork.pollRedemptionResultCallCount == 1)
   }
+
+  @Test("Init doesn't start the cold-launch Stripe poll")
+  func testInit_doesNotStartColdLaunchPoll() async {
+    guard #available(iOS 14.0, *) else {
+      return
+    }
+
+    let superwall = Superwall(dependencyContainer: dependencyContainer)
+    let mockStorage = StorageMock(internalRedeemResponse: nil)
+    let mockNetwork = NetworkMock(
+      options: dependencyContainer.makeSuperwallOptions(),
+      factory: dependencyContainer
+    )
+
+    // Seed a pending checkout so a poll would fire if anything kicked one off.
+    mockStorage.save(
+      PendingStripeCheckoutPollState(
+        checkoutContextId: "ctx_cold",
+        productId: "prod_cold"
+      ),
+      forType: PendingStripeCheckoutPollStorage.self
+    )
+    mockNetwork.pollRedemptionResultResponses = [.failure(NetworkError.unknown)]
+
+    _ = WebEntitlementRedeemer(
+      network: mockNetwork,
+      storage: mockStorage,
+      entitlementsInfo: dependencyContainer.entitlementsInfo,
+      delegate: dependencyContainer.delegateAdapter,
+      purchaseController: MockPurchaseController(),
+      receiptManager: dependencyContainer.receiptManager,
+      factory: dependencyContainer,
+      superwall: superwall
+    )
+
+    // Give a stray init-spawned task time to run before asserting it didn't.
+    try? await Task.sleep(nanoseconds: 300_000_000)
+    #expect(mockNetwork.pollRedemptionResultCallCount == 0)
+  }
+
+  @Test("Cold-launch kick-off polls a pending Stripe checkout")
+  func testPollPendingStripeCheckoutOnColdLaunch_pollsPendingCheckout() async {
+    guard #available(iOS 14.0, *) else {
+      return
+    }
+
+    let superwall = Superwall(dependencyContainer: dependencyContainer)
+    let mockStorage = StorageMock(internalRedeemResponse: nil)
+    let mockNetwork = NetworkMock(
+      options: dependencyContainer.makeSuperwallOptions(),
+      factory: dependencyContainer
+    )
+
+    mockStorage.save(
+      PendingStripeCheckoutPollState(
+        checkoutContextId: "ctx_cold",
+        productId: "prod_cold"
+      ),
+      forType: PendingStripeCheckoutPollStorage.self
+    )
+    mockNetwork.pollRedemptionResultResponses = [.failure(NetworkError.unknown)]
+
+    let redeemer = WebEntitlementRedeemer(
+      network: mockNetwork,
+      storage: mockStorage,
+      entitlementsInfo: dependencyContainer.entitlementsInfo,
+      delegate: dependencyContainer.delegateAdapter,
+      purchaseController: MockPurchaseController(),
+      receiptManager: dependencyContainer.receiptManager,
+      factory: dependencyContainer,
+      superwall: superwall
+    )
+
+    redeemer.pollPendingStripeCheckoutOnColdLaunch()
+
+    // The kick-off spawns a task; wait for the poll to land.
+    for _ in 0..<100 where mockNetwork.pollRedemptionResultCallCount == 0 {
+      try? await Task.sleep(nanoseconds: 50_000_000)
+    }
+    #expect(mockNetwork.pollRedemptionResultCallCount == 1)
+  }
 }