Track free trial start for Stripe purchases

CHANGELOG.md

@@ -14,7 +14,7 @@ The changelog for `SuperwallKit`. Also see the [releases](https://github.com/sup
 - Makes `device.isSandbox` more reliable.
 - Fixes the web restore alert not showing the "Yes" action button and "Cancel" incorrectly triggering the restore action.
 - Fixes a rare issue where a user's subscription could remain active after a refund, preventing paywalls from being shown.
-- Fixes trial eligibility for Stripe products.
+- Fixes trial eligibility for Stripe paywalls and tracks `freeTrial_start`.
 - Fixes an issue where `transaction_complete` could be missing transaction information when a crossgrade occurred while using a purchase controller.
 - Fixes terminated webviews refreshing in a loop on low RAM devices.
 

Sources/SuperwallKit/Web/WebEntitlementRedeemer.swift

@@ -250,7 +250,7 @@ actor WebEntitlementRedeemer {
     let event = InternalSuperwallEvent.Transaction(
       state: .abandon(product),
       paywallInfo: paywallInfo,
-      product: nil,
+      product: product,
       transaction: nil,
       source: .internal,
       isObserved: false,
@@ -561,20 +561,32 @@ actor WebEntitlementRedeemer {
         await self.delegate.didRedeemLink(result: codeResult)
       }
 
-      // Schedule free trial notification if applicable
+      // Track free trial start and schedule notification if applicable
       if case .success(_, let redemptionInfo) = codeResult,
-        let product = redemptionInfo.paywallInfo?.product,
-        product.trialPeriodDays > 0,
+        let redemptionProduct = redemptionInfo.paywallInfo?.product,
+        redemptionProduct.trialPeriodDays > 0,
         let paywallVc = superwall.paywallViewController {
         let paywallInfo = await paywallVc.info
-        let notifications = paywallInfo.localNotifications.filter {
-          $0.type == .trialStarted
+        if paywallInfo.isFreeTrialAvailable {
+          let product = StoreProduct.blank(
+            productIdentifier: redemptionProduct.identifier
+          )
+          await superwall.track(
+            InternalSuperwallEvent.FreeTrialStart(
+              paywallInfo: paywallInfo,
+              product: product,
+              transaction: nil
+            )
+          )
+          let notifications = paywallInfo.localNotifications.filter {
+            $0.type == .trialStarted
+          }
+          await self.notificationScheduler.scheduleNotifications(
+            notifications,
+            fromPaywallId: paywallInfo.identifier,
+            factory: self.factory
+          )
         }
-        await self.notificationScheduler.scheduleNotifications(
-          notifications,
-          fromPaywallId: paywallInfo.identifier,
-          factory: self.factory
-        )
       }
 
       if let paywallVc = superwall.paywallViewController,