feat: getStorefront method implementation for fetching App Store and Google Play region

android/src/play/java/com/dooboolab/rniap/RNIapModule.kt

@@ -4,11 +4,15 @@ import android.util.Log
 import com.android.billingclient.api.AcknowledgePurchaseParams
 import com.android.billingclient.api.BillingClient
 import com.android.billingclient.api.BillingClientStateListener
+import com.android.billingclient.api.BillingConfig
+import com.android.billingclient.api.BillingConfigResponseListener
 import com.android.billingclient.api.BillingFlowParams
 import com.android.billingclient.api.BillingFlowParams.SubscriptionUpdateParams
 import com.android.billingclient.api.BillingResult
 import com.android.billingclient.api.ConsumeParams
 import com.android.billingclient.api.ConsumeResponseListener
+import com.android.billingclient.api.GetBillingConfigParams
+import com.android.billingclient.api.GetBillingConfigParams.Builder
 import com.android.billingclient.api.ProductDetails
 import com.android.billingclient.api.Purchase
 import com.android.billingclient.api.PurchaseHistoryRecord
@@ -707,6 +711,24 @@ class RNIapModule(
     @ReactMethod
     fun getPackageName(promise: Promise) = promise.resolve(reactApplicationContext.packageName)
 
+    @ReactMethod
+    fun getStorefront(promise: Promise) {
+        ensureConnection(
+            promise,
+        ) { billingClient ->
+            billingClient.getBillingConfigAsync(
+                GetBillingConfigParams.newBuilder().build(),
+                BillingConfigResponseListener { result: BillingResult, config: BillingConfig? ->
+                    if (result.getResponseCode() == BillingClient.BillingResponseCode.OK) {
+                        promise.safeResolve(config?.getCountryCode())
+                    } else {
+                        promise.safeReject(result?.getResponseCode().toString(), result?.getDebugMessage())
+                    }
+                },
+            )
+        }
+    }
+
     private fun sendEvent(
         reactContext: ReactContext,
         eventName: String,

ios/RNIapIosSk2.m

@@ -95,5 +95,9 @@ @interface RCT_EXTERN_MODULE (RNIapIosSk2, NSObject)
                   (NSString*)sku
                   resolve:(RCTPromiseResolveBlock)resolve
                   reject:(RCTPromiseRejectBlock)reject)
+
+RCT_EXTERN_METHOD(getStorefront:
+                  (RCTPromiseResolveBlock)resolve
+                  reject:(RCTPromiseRejectBlock)reject)
 @end
 #endif

ios/RNIapIosSk2.swift

@@ -102,6 +102,11 @@ protocol Sk2Delegate {
         reject: @escaping RCTPromiseRejectBlock
     )
 
+    func getStorefront(
+        _ resolve: @escaping RCTPromiseResolveBlock,
+        reject: @escaping RCTPromiseRejectBlock
+    )
+
     func startObserving()
     func stopObserving()
 }
@@ -240,6 +245,13 @@ class DummySk2: Sk2Delegate {
         reject(errorCode, errorMessage, nil)
     }
 
+    func getStorefront(
+        _ resolve: @escaping RCTPromiseResolveBlock,
+        reject: @escaping RCTPromiseRejectBlock
+    ) {
+        reject(errorCode, errorMessage, nil)
+    }
+
     func startObserving() {
     }
 
@@ -416,6 +428,13 @@ class RNIapIosSk2: RCTEventEmitter, Sk2Delegate {
     ) {
         delegate.beginRefundRequest(sku, resolve: resolve, reject: reject)
     }
+
+    @objc public func getStorefront(
+        _ resolve: @escaping RCTPromiseResolveBlock = { _ in },
+        reject: @escaping RCTPromiseRejectBlock = { _, _, _ in }
+    ) {
+        delegate.getStorefront(resolve, reject: reject)
+    }
 }
 
 @available(iOS 15.0, tvOS 15.0, *)
@@ -1046,4 +1065,11 @@ class RNIapIosSk2iOS15: Sk2Delegate {
         reject(IapErrors.E_USER_CANCELLED.rawValue, "This method is not available on tvOS", nil)
         #endif
     }
+
+    public func getStorefront(_ resolve: @escaping RCTPromiseResolveBlock, reject: @escaping RCTPromiseRejectBlock) {
+        Task {
+            let storefront = await Storefront.current
+            resolve(storefront?.countryCode)
+        }
+    }
 }

src/iap.ts

@@ -331,7 +331,7 @@ Note that this is only for backaward compatiblity. It won't publish to transacti
 @param {automaticallyFinishRestoredTransactions}:boolean. (IOS Sk1 only) When `true`, all the transactions that are returned are automatically
 finished. This means that if you call this method again you won't get the same result on the same device. On the other hand, if `false` you'd
 have to manually finish the returned transaction once you have delivered the content to your user.
-@param {onlyIncludeActiveItems}:boolean. (IOS Sk2 only). Defaults to false, meaning that it will return one transaction per item purchased. 
+@param {onlyIncludeActiveItems}:boolean. (IOS Sk2 only). Defaults to false, meaning that it will return one transaction per item purchased.
 @See https://developer.apple.com/documentation/storekit/transaction/3851204-currententitlements for details
  */
 export const getPurchaseHistory = ({
@@ -457,7 +457,7 @@ const App = () => {
 ```
 @param {alsoPublishToEventListener}:boolean When `true`, every element will also be pushed to the purchaseUpdated listener.
 Note that this is only for backaward compatiblity. It won't publish to transactionUpdated (Storekit2) Defaults to `false`
-@param {onlyIncludeActiveItems}:boolean. (IOS Sk2 only). Defaults to true, meaning that it will return the transaction if suscription has not expired. 
+@param {onlyIncludeActiveItems}:boolean. (IOS Sk2 only). Defaults to true, meaning that it will return the transaction if suscription has not expired.
 @See https://developer.apple.com/documentation/storekit/transaction/3851204-currententitlements for details
  *
  */
@@ -933,3 +933,36 @@ export const deepLinkToSubscriptions = ({
     }) || (() => Promise.reject(new Error('Unsupported Platform')))
   )();
 };
+
+/**
+ * Get App Store and Google Play device region.
+ *
+ * App Store: string - ISO 3166-1 Alpha-3 country code representation https://developer.apple.com/documentation/storekit/storefront.
+ *
+ * Google Play: string - ISO-3166-1 alpha2 country code representation https://developer.android.com/reference/com/android/billingclient/api/BillingConfig#getCountryCode()
+ *
+ * ```tsx
+ * import React from 'react';
+ * import {getStorefront} from 'react-native-iap';
+ *
+ * const App = () => {
+ *   React.useEffect(() => {
+ *     getStorefront().then((countryCode) => {
+ *       // ... handle region
+ *     });
+ *   }, []);
+ * };
+ * ```
+ */
+export const getStorefront = (): Promise<string> => {
+  return (
+    Platform.select({
+      android: async () => {
+        return await RNIapModule.getStorefront();
+      },
+      ios: async () => {
+        return await RNIapIosSk2.getStorefront();
+      },
+    }) || (() => Promise.reject(new Error('Unsupported Platform')))
+  )();
+};

src/modules/android.ts

@@ -58,6 +58,7 @@ type ConsumeProduct = (
 
 type StartListening = () => Promise<void>;
 type GetPackageName = () => Promise<string>;
+type GetStorefront = () => Promise<string>;
 
 export interface AndroidModuleProps extends NativeModuleProps {
   flushFailedPurchasesCachedAsPending: FlushFailedPurchasesCachedAsPending;
@@ -70,6 +71,7 @@ export interface AndroidModuleProps extends NativeModuleProps {
   /** @deprecated to be renamed to sendUnconsumedPurchases if not removed completely */
   startListening: StartListening;
   getPackageName: GetPackageName;
+  getStorefront: GetStorefront;
   isFeatureSupported: (feature: Android.FeatureType) => Promise<boolean>;
 }
 

src/modules/iosSk2.ts

@@ -37,6 +37,7 @@ type finishTransaction = (transactionIdentifier: string) => Promise<boolean>;
 type getPendingTransactions = () => Promise<ProductPurchase[]>;
 type presentCodeRedemptionSheet = () => Promise<null>;
 type showManageSubscriptions = () => Promise<null>;
+type getStorefront = () => Promise<string>;
 
 export interface IosModulePropsSk2 extends NativeModuleProps {
   isAvailable(): number;
@@ -58,6 +59,7 @@ export interface IosModulePropsSk2 extends NativeModuleProps {
   showManageSubscriptions: showManageSubscriptions;
   disable: () => Promise<null>;
   beginRefundRequest: (sku: string) => Promise<RefundRequestStatus>;
+  getStorefront: getStorefront;
 }
 
 /**