[Order Details] Mitigate crash on shipping lines due async operations (#15808)

Author: iamgabrielma

WooCommerce/Classes/ViewModels/Order Details/OrderDetailsDataSource.swift

@@ -113,6 +113,11 @@ final class OrderDetailsDataSource: NSObject {
     ///
     var orderHasLocalReceipt: Bool = false
 
+    /// Whether the order is eligible for backend receipt generation.
+    /// This is calculated during sync to avoid async calls during section building.
+    ///
+    var isEligibleForBackendReceipt: Bool = false
+
     /// Closure to be executed when the cell was tapped.
     ///
     var onCellAction: ((CellActionType, IndexPath?) -> Void)?
@@ -238,9 +243,7 @@ final class OrderDetailsDataSource: NSObject {
     ///
     var orderSubscriptions: [Subscription] = [] {
         didSet {
-            Task { @MainActor in
-                await reloadSections()
-            }
+            reloadSections()
         }
     }
 
@@ -869,8 +872,19 @@ private extension OrderDetailsDataSource {
 
     private func configureAggregateOrderItem(cell: ProductDetailsTableViewCell, at indexPath: IndexPath) {
         cell.selectionStyle = .default
+        guard let aggregateItem = aggregateOrderItems[safe: indexPath.row] else {
+            ServiceLocator.crashLogging.logMessage(
+                "Invalid aggregate order item index in OrderDetailsDataSource",
+                properties: [
+                    "row": indexPath.row,
+                    "section": indexPath.section,
+                    "availableAggregateItemsCount": aggregateOrderItems.count
+                ],
+                level: .error
+            )
+            return
+        }
 
-        let aggregateItem = aggregateOrderItems[indexPath.row]
         let imageURL: URL? = {
             guard let imageURLString = aggregateItem.variationID != 0 ?
                     lookUpProductVariation(productID: aggregateItem.productID, variationID: aggregateItem.variationID)?.image?.src:
@@ -1046,7 +1060,18 @@ private extension OrderDetailsDataSource {
     }
 
     private func configureShippingLine(cell: HostingConfigurationTableViewCell<ShippingLineRowView>, at indexPath: IndexPath) {
-        let shippingLine = shippingLines[indexPath.row]
+        guard let shippingLine = shippingLines[safe: indexPath.row] else {
+            ServiceLocator.crashLogging.logMessage(
+                "Invalid shipping line index in OrderDetailsDataSource",
+                properties: [
+                    "row": indexPath.row,
+                    "section": indexPath.section,
+                    "availableShippingLinesCount": shippingLines.count
+                ],
+                level: .error
+            )
+            return
+        }
         let viewModel = ShippingLineRowViewModel(shippingLine: shippingLine, currency: order.currency, shippingMethods: siteShippingMethods, editable: false)
         let view = ShippingLineRowView(viewModel: viewModel)
 
@@ -1182,8 +1207,7 @@ extension OrderDetailsDataSource {
     /// When: Customer Note == nil          >>> Hide Customer Note
     /// When: Shipping == nil               >>> Display: Shipping = "No address specified"
     ///
-    @MainActor
-    func reloadSections() async {
+    func reloadSections() {
         // Freezes any data that require lookup after the sections are reloaded, in case the data from a ResultsController changes before the next reload.
         refunds = resultsControllers.refunds
         customAmounts = resultsControllers.feeLines
@@ -1202,7 +1226,7 @@ extension OrderDetailsDataSource {
         )
 
         var sections = buildStaticSections().compactMap { $0 }
-        let paymentSection = await createPaymentSection()
+        let paymentSection = createPaymentSection()
 
         // Finds the position between shippingLines and customerInformation to inject the payment section,
         // otherwise will always appear last because of being async
@@ -1506,8 +1530,7 @@ extension OrderDetailsDataSource {
         ]
     }
 
-    @MainActor
-    private func createPaymentSection() async -> Section {
+    private func createPaymentSection() -> Section {
         var rows: [Row] = [.payment, .customerPaid]
         if condensedRefunds.isNotEmpty {
             rows.append(contentsOf: Array(repeating: .refund, count: condensedRefunds.count))
@@ -1518,7 +1541,7 @@ extension OrderDetailsDataSource {
         }
         if orderHasLocalReceipt {
             rows.append(.seeLegacyReceipt)
-        } else if await isEligibleForBackendReceipt() {
+        } else if isEligibleForBackendReceipt {
             rows.append(.seeReceipt)
         }
         if isEligibleForRefund {
@@ -1531,15 +1554,6 @@ extension OrderDetailsDataSource {
         )
     }
 
-    @MainActor
-    private func isEligibleForBackendReceipt() async -> Bool {
-        return await withCheckedContinuation { continuation in
-            receiptEligibilityUseCase.isEligibleForReceipt(order.status, onCompletion: { isEligible in
-                continuation.resume(returning: isEligible)
-            })
-        }
-    }
-
     func refund(at indexPath: IndexPath) -> Refund? {
         let index = indexPath.row - Constants.paymentCell - Constants.paidByCustomerCell
         let condensedRefund = condensedRefunds[index]

WooCommerce/Classes/ViewModels/Order Details/OrderDetailsViewModel.swift

@@ -126,9 +126,7 @@ final class OrderDetailsViewModel {
     var orderNotes: [OrderNote] = [] {
         didSet {
             dataSource.orderNotes = orderNotes
-            Task { @MainActor in
-                await dataSource.reloadSections()
-            }
+            dataSource.reloadSections()
         }
     }
 
@@ -321,6 +319,16 @@ extension OrderDetailsViewModel {
             group.leave()
         }
 
+        // Receipt eligibility need to be synced after the order but before we complete the order sync group,
+        // otherwise we risk to crash due out of bounds when rendering the rest of the rows that require reloading sections.
+        group.enter()
+        Task { @MainActor in
+            defer {
+                group.leave()
+            }
+            dataSource.isEligibleForBackendReceipt = await isEligibleForBackendReceipt()
+        }
+
         group.enter()
         checkOrderAddOnFeatureSwitchState {
             onReloadSections?()
@@ -462,8 +470,8 @@ extension OrderDetailsViewModel {
 
 
 extension OrderDetailsViewModel {
-    func reloadSections() async {
-        await dataSource.reloadSections()
+    func reloadSections() {
+        dataSource.reloadSections()
     }
 }
 
@@ -1026,6 +1034,15 @@ extension OrderDetailsViewModel {
                                                    status: .pending, onCompletion: { _ in })
         stores.dispatch(action)
     }
+
+    @MainActor
+    private func isEligibleForBackendReceipt() async -> Bool {
+        return await withCheckedContinuation { continuation in
+            receiptEligibilityUseCase.isEligibleForReceipt(order.status) { isEligible in
+                continuation.resume(returning: isEligible)
+            }
+        }
+    }
 }
 
 // MARK: - Notices

WooCommerce/Classes/ViewRelated/Orders/Order Details/OrderDetailsViewController.swift

@@ -265,9 +265,7 @@ private extension OrderDetailsViewController {
 private extension OrderDetailsViewController {
 
     func reloadSections() {
-        Task {
-            await viewModel.reloadSections()
-        }
+        viewModel.reloadSections()
     }
 }