Order details: Fix crash when reloading orders (#15764)

Author: itsmeichigo

RELEASE-NOTES.txt

@@ -3,6 +3,7 @@
 
 22.7
 -----
+- [*] Order Details: Fix crash when reloading data [https://github.com/woocommerce/woocommerce-ios/pull/15764]
 - [*] Shipping Labels: Improved shipment management UI by hiding remove/merge options instead of disabling them, hiding merge option for orders with 2 or fewer unfulfilled shipments, and hiding the ellipsis menu when no remove/merge actions are available [https://github.com/woocommerce/woocommerce-ios/pull/15760]
 - [**] POS: a POS tab in the tab bar is now available in the app for stores eligible for Point of Sale, instead of the previous entry point in the Menu tab. [https://github.com/woocommerce/woocommerce-ios/pull/15766]
 

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

@@ -136,27 +136,23 @@ final class OrderDetailsDataSource: NSObject {
 
     /// Order shipment tracking list
     ///
-    var orderTracking: [ShipmentTracking] {
-        return resultsControllers.orderTracking
-    }
+    var orderTracking: [ShipmentTracking] = []
 
     /// Order statuses list
     ///
-    var currentSiteStatuses: [OrderStatus] {
-        return resultsControllers.currentSiteStatuses
-    }
+    var currentSiteStatuses: [OrderStatus] = []
 
     /// Products from an Order
     ///
-    var products: [Product] {
-        return resultsControllers.products
-    }
+    var products: [Product] = []
+
+    /// Product variations from an order
+    ///
+    var productVariations: [ProductVariation] = []
 
     /// Custom amounts (fees) from an Order
     ///
-    var customAmounts: [OrderFeeLine] {
-        return resultsControllers.feeLines
-    }
+    var customAmounts: [OrderFeeLine] = []
 
     /// OrderItemsRefund Count
     ///
@@ -166,19 +162,13 @@ final class OrderDetailsDataSource: NSObject {
 
     /// Refunds on an Order
     ///
-    var refunds: [Refund] {
-        return resultsControllers.refunds
-    }
+    var refunds: [Refund] = []
 
-    var addOnGroups: [AddOnGroup] {
-        resultsControllers.addOnGroups
-    }
+    var addOnGroups: [AddOnGroup] = []
 
     /// Shipping Methods list
     ///
-    var siteShippingMethods: [ShippingMethod] {
-        resultsControllers.siteShippingMethods
-    }
+    var siteShippingMethods: [ShippingMethod] = []
 
     /// Shipping Labels for an Order
     ///
@@ -1171,7 +1161,7 @@ extension OrderDetailsDataSource {
     }
 
     private func lookUpProductVariation(productID: Int64, variationID: Int64) -> ProductVariation? {
-        return resultsControllers.productVariations.filter({ $0.productID == productID && $0.productVariationID == variationID }).first
+        return productVariations.filter({ $0.productID == productID && $0.productVariationID == variationID }).first
     }
 
     func lookUpRefund(by refundID: Int64) -> Refund? {
@@ -1195,12 +1185,20 @@ extension OrderDetailsDataSource {
     @MainActor
     func reloadSections() async {
         // 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
+        orderTracking = resultsControllers.orderTracking
+        currentSiteStatuses = resultsControllers.currentSiteStatuses
+        products = resultsControllers.products
+        addOnGroups = resultsControllers.addOnGroups
+        siteShippingMethods = resultsControllers.siteShippingMethods
+        productVariations = resultsControllers.productVariations
         shippingLabels = resultsControllers.shippingLabels
         shippingLabelOrderItemsAggregator = AggregatedShippingLabelOrderItems(
             shippingLabels: shippingLabels,
             orderItems: items,
             products: products,
-            productVariations: resultsControllers.productVariations
+            productVariations: productVariations
         )
 
         var sections = buildStaticSections().compactMap { $0 }