feat: add currency regarding the new API (#2615)

- addressing the missing currency issue in Storekit 2:
https://developer.apple.com/forums/thread/689978
- adding from here:
https://developer.apple.com/documentation/storekit/product/4044347-priceformatstyle
- as few changes as possible

ios/IapSerializationUtils.swift

@@ -19,7 +19,8 @@ func serialize(_ p: Product) -> [String: Any?] {
         "jsonRepresentation": serializeDebug(p.jsonRepresentation),
         "price": p.price,
         "subscription": serialize(p.subscription),
-        "type": serialize(p.type)
+        "type": serialize(p.type),
+        "currency": p.priceFormatStyle.currencyCode
     ]
 }
 

src/types/appleSk2.ts

@@ -36,6 +36,7 @@ export type SubscriptionInfo = {
 export type RefundRequestStatus = 'success' | 'userCancelled';
 
 export type ProductSk2 = {
+  currency: string;
   description: string;
   displayName: string;
   displayPrice: string;
@@ -51,6 +52,7 @@ export const productSk2Map = ({
   description,
   displayName,
   price,
+   currency,
   displayPrice,
 }: ProductSk2): ProductIOS => {
   const prod: ProductIOS = {
@@ -60,7 +62,7 @@ export const productSk2Map = ({
     type: 'iap',
     price: String(price),
     localizedPrice: displayPrice,
-    currency: '', // Not available on new API, use localizedPrice instead
+    currency
   };
   return prod;
 };
@@ -70,6 +72,7 @@ export const subscriptionSk2Map = ({
   description,
   displayName,
   price,
+  currency,
   displayPrice,
   subscription,
 }: ProductSk2): SubscriptionIOS => {
@@ -81,7 +84,7 @@ export const subscriptionSk2Map = ({
     type: 'subs',
     price: String(price),
     localizedPrice: displayPrice,
-    currency: '', // Not available on new API, use localizedPrice instead
+    currency,
     subscriptionPeriodNumberIOS: `${subscription?.subscriptionPeriod?.value}`,
     subscriptionPeriodUnitIOS:
       subscription?.subscriptionPeriod?.unit.toUpperCase() as SubscriptionIosPeriod,