Dart-side handling of sku->skus

packages/in_app_purchase/in_app_purchase_android/android/src/main/java/io/flutter/plugins/inapppurchase/Translator.java

@@ -61,13 +61,6 @@ static HashMap<String, Object> fromPurchase(Purchase purchase) {
     info.put("purchaseTime", purchase.getPurchaseTime());
     info.put("purchaseToken", purchase.getPurchaseToken());
     info.put("signature", purchase.getSignature());
-    // TODO(garyq): Remove deprecated `sku`.
-    // `sku` was deprecated in billion 4.0, but we cannot directly remove it from our
-    // API instantly. Thus, for backwards compatibility, we pass the first sku here
-    // and include the rest of the list under `skus`.
-    if (!skus.isEmpty()) {
-      info.put("sku", skus.get(0));
-    }
     info.put("skus", skus);
     info.put("isAutoRenewing", purchase.isAutoRenewing());
     info.put("originalJson", purchase.getOriginalJson());
@@ -90,13 +83,6 @@ static HashMap<String, Object> fromPurchaseHistoryRecord(
     info.put("purchaseTime", purchaseHistoryRecord.getPurchaseTime());
     info.put("purchaseToken", purchaseHistoryRecord.getPurchaseToken());
     info.put("signature", purchaseHistoryRecord.getSignature());
-    // TODO(garyq): Remove deprecated `sku`.
-    // `sku` was deprecated in billion 4.0, but we cannot directly remove it from our
-    // API instantly. Thus, for backwards compatibility, we pass the first sku here
-    // and include the rest of the list under `skus`.
-    if (!skus.isEmpty()) {
-      info.put("sku", skus.get(0));
-    }
     info.put("skus", skus);
     info.put("developerPayload", purchaseHistoryRecord.getDeveloperPayload());
     info.put("originalJson", purchaseHistoryRecord.getOriginalJson());

packages/in_app_purchase/in_app_purchase_android/lib/src/billing_client_wrappers/purchase_wrapper.dart

@@ -34,16 +34,16 @@ class PurchaseWrapper {
     required this.purchaseToken,
     required this.signature,
     @Deprecated('Use skus instead')
-    this.sku = '', // Deprecated
-    required this.skus,
+    String? sku, // Deprecated
+    this.skus,
     required this.isAutoRenewing,
     required this.originalJson,
     this.developerPayload,
     required this.isAcknowledged,
     required this.purchaseState,
     this.obfuscatedAccountId,
     this.obfuscatedProfileId,
-  });
+  }) : _sku(sku);
 
   /// Factory for creating a [PurchaseWrapper] from a [Map] with the purchase details.
   factory PurchaseWrapper.fromJson(Map<String, dynamic> map) =>
@@ -108,7 +108,8 @@ class PurchaseWrapper {
   /// The product ID of this purchase.
   @JsonKey(defaultValue: '')
   @Deprecated('Use skus instead')
-  final String sku;
+  final String get sku => _sku ?? skus.first;
+  final String? _sku;
 
   /// The product IDs of this purchase.
   @JsonKey(defaultValue: <String>[])