Always call readyForPromotedProduct on main thread/actor

.circleci/config.yml

@@ -1345,6 +1345,7 @@ workflows:
         - not: << pipeline.parameters.generate_revenuecatui_snapshots >>
     jobs:
       - lint
+      - run-test-ios-13
       - run-test-ios-17
       - run-test-ios-18
       - pod-lib-lint

Sources/Purchasing/Purchases/Purchases.swift

@@ -1598,7 +1598,21 @@ extension Purchases: PurchasesOrchestratorDelegate {
      */
     func readyForPromotedProduct(_ product: StoreProduct,
                                  purchase startPurchase: @escaping StartPurchaseBlock) {
-        self.delegate?.purchases?(self, readyForPromotedProduct: product, purchase: startPurchase)
+
+        switch self.systemInfo.storeKitVersion.effectiveVersion {
+        case .storeKit1:
+            // Calling the delegate method on the main actor causes test failures on iOS 14-16, so instead
+            // we dispatch to the main thread, which doesn't cause the failures.
+            OperationDispatcher.default.dispatchOnMainThread {
+                self.delegate?.purchases?(self, readyForPromotedProduct: product, purchase: startPurchase)
+            }
+        case .storeKit2:
+            // Ensure that the delegate method is called on the main actor for StoreKit 2.
+            OperationDispatcher.default.dispatchOnMainActor {
+                self.delegate?.purchases?(self, readyForPromotedProduct: product, purchase: startPurchase)
+            }
+        }
+
     }
 
 #if os(iOS) || targetEnvironment(macCatalyst) || VISION_OS

Tests/UnitTests/Purchasing/Purchases/PurchasesDeferredPurchasesTests.swift

@@ -177,6 +177,12 @@ class PurchaseDeferredPurchasesSK2Tests: BasePurchasesTests {
             for: self.product
         )
 
+        waitUntil { completed in
+            if self.purchasesDelegate.makeDeferredPurchase != nil {
+                completed()
+            }
+        }
+
         expect(self.purchasesDelegate.makeDeferredPurchase).toNot(beNil())
 
         expect(self.purchasesDelegate.promoProduct) == StoreProduct(sk1Product: self.product)