feat: add iOS 16.0+ app transaction support with SDK version check (#113)

## Summary
- Added getAppTransactionIOS method for iOS 16.0+ devices
- Implemented compiler version check to ensure Xcode 15.0+ with iOS 16.0
SDK
- Added comprehensive documentation and test UI in example app

## Changes
- **iOS Module**: Added #if compiler(>=5.7) check to ensure proper SDK
version
- **TypeScript**: Updated method documentation with requirements
- **Docs**: Added warning box about runtime and build requirements  
- **Example**: Added test button to verify getAppTransaction
functionality

## Test plan
- [ ] Build with Xcode 15.0+ - verify compilation succeeds
- [ ] Build with older Xcode - verify appropriate error message
- [ ] Test on iOS 16.0+ device - verify getAppTransaction works
- [ ] Test on iOS < 16.0 - verify appropriate runtime error
- [ ] Test example app button functionality

Author: hyochan

docs/docs/api/methods/core-methods.md

@@ -130,6 +130,11 @@ const fetchStorefront = async () => {
 
 Gets app transaction information for iOS apps (iOS 16.0+). AppTransaction represents the initial purchase that unlocked the app, useful for premium apps or apps that were previously paid.
 
+> **⚠️ Important Requirements:**
+> - **Runtime:** iOS 16.0 or later
+> - **Build Environment:** Xcode 15.0+ with iOS 16.0 SDK
+> - If built with older SDK versions, the method will throw an error
+
 ```tsx
 import {getAppTransaction} from 'expo-iap';
 

example/__tests__/ios-functions.test.tsx

@@ -41,6 +41,98 @@ describe('iOS Functions Tests', () => {
     });
   });
 
+  describe('getAppTransactionIOS Tests', () => {
+    beforeEach(() => {
+      jest.clearAllMocks();
+    });
+
+    it('should call getAppTransactionIOS successfully', async () => {
+      const mockAppTransaction: ExpoIap.AppTransactionIOS = {
+        appTransactionID: 'test-transaction-id',
+        bundleID: 'com.example.testapp',
+        appVersion: '2.0.0',
+        originalAppVersion: '1.0.0',
+        originalPurchaseDate: 1234567890000,
+        deviceVerification: 'device-verification-data',
+        deviceVerificationNonce: 'nonce-value',
+        environment: 'Production',
+        signedDate: 1234567900000,
+        appID: 123456789,
+        appVersionID: 987654321,
+        originalPlatform: 'iOS',
+        preorderDate: undefined,
+      };
+
+      (ExpoIap.getAppTransactionIOS as jest.Mock).mockResolvedValue(
+        mockAppTransaction,
+      );
+
+      const result = await ExpoIap.getAppTransactionIOS();
+
+      expect(ExpoIap.getAppTransactionIOS).toHaveBeenCalledTimes(1);
+      expect(result).toEqual(mockAppTransaction);
+      expect(result?.appTransactionID).toBe('test-transaction-id');
+      expect(result?.environment).toBe('Production');
+    });
+
+    it('should handle null response from getAppTransactionIOS', async () => {
+      (ExpoIap.getAppTransactionIOS as jest.Mock).mockResolvedValue(null);
+
+      const result = await ExpoIap.getAppTransactionIOS();
+
+      expect(ExpoIap.getAppTransactionIOS).toHaveBeenCalledTimes(1);
+      expect(result).toBeNull();
+    });
+
+    it('should handle errors from getAppTransactionIOS', async () => {
+      const mockError = new Error('iOS 16.0+ required');
+      (ExpoIap.getAppTransactionIOS as jest.Mock).mockRejectedValue(mockError);
+
+      await expect(ExpoIap.getAppTransactionIOS()).rejects.toThrow(
+        'iOS 16.0+ required',
+      );
+      expect(ExpoIap.getAppTransactionIOS).toHaveBeenCalledTimes(1);
+    });
+
+    it('should handle SDK version error', async () => {
+      const sdkError = new Error(
+        'getAppTransaction requires Xcode 15.0+ with iOS 16.0 SDK for compilation',
+      );
+      (ExpoIap.getAppTransactionIOS as jest.Mock).mockRejectedValue(sdkError);
+
+      await expect(ExpoIap.getAppTransactionIOS()).rejects.toThrow(
+        'getAppTransaction requires Xcode 15.0+ with iOS 16.0 SDK for compilation',
+      );
+    });
+
+    it('should handle deprecated getAppTransaction function', async () => {
+      const mockTransaction: ExpoIap.AppTransactionIOS = {
+        appTransactionID: 'deprecated-test',
+        bundleID: 'com.example.app',
+        appVersion: '1.0.0',
+        originalAppVersion: '1.0.0',
+        originalPurchaseDate: Date.now(),
+        deviceVerification: 'verification',
+        deviceVerificationNonce: 'nonce',
+        environment: 'Sandbox',
+        signedDate: Date.now(),
+        appID: 123456,
+        appVersionID: 789012,
+        originalPlatform: 'iOS',
+      };
+
+      (ExpoIap.getAppTransaction as jest.Mock).mockResolvedValue(
+        mockTransaction,
+      );
+
+      const result = await ExpoIap.getAppTransaction();
+
+      expect(ExpoIap.getAppTransaction).toHaveBeenCalledTimes(1);
+      expect(result).toEqual(mockTransaction);
+      expect(result?.environment).toBe('Sandbox');
+    });
+  });
+
   describe('Type Exports', () => {
     it('should have proper type structure for AppTransactionIOS', () => {
       // Type checking through object creation
@@ -95,4 +187,4 @@ describe('iOS Functions Tests', () => {
       expect(ExpoIap.presentCodeRedemptionSheet).toBeDefined();
     });
   });
-});
+});

example/app/purchase-flow.tsx

@@ -8,7 +8,7 @@ import {
   ScrollView,
   Platform,
 } from 'react-native';
-import {requestPurchase, useIAP} from '../../src';
+import {requestPurchase, useIAP, getAppTransactionIOS} from '../../src';
 import type {
   Product,
   ProductPurchase,
@@ -196,6 +196,25 @@ export default function PurchaseFlow() {
           {'\n'}• CPK React Native compliance
         </Text>
       </View>
+      
+      {Platform.OS === 'ios' && (
+        <View style={styles.section}>
+          <Text style={styles.sectionTitle}>Test iOS 16.0 Feature</Text>
+          <TouchableOpacity
+            style={styles.testButton}
+            onPress={async () => {
+              try {
+                const appTransaction = await getAppTransactionIOS();
+                Alert.alert('Success', `App Transaction: ${JSON.stringify(appTransaction)}`);
+              } catch (error: any) {
+                Alert.alert('Error', error.message || 'Failed to get app transaction');
+              }
+            }}
+          >
+            <Text style={styles.testButtonText}>Test getAppTransaction</Text>
+          </TouchableOpacity>
+        </View>
+      )}
     </ScrollView>
   );
 }
@@ -339,4 +358,16 @@ const styles = StyleSheet.create({
     color: '#0066cc',
     lineHeight: 20,
   },
+  testButton: {
+    backgroundColor: '#FF6B6B',
+    paddingHorizontal: 20,
+    paddingVertical: 12,
+    borderRadius: 8,
+    alignItems: 'center',
+  },
+  testButtonText: {
+    color: '#fff',
+    fontWeight: '600',
+    fontSize: 16,
+  },
 });

ios/ExpoIapModule.swift

@@ -257,6 +257,7 @@ public class ExpoIapModule: Module {
 
         AsyncFunction("getAppTransaction") { () async throws -> [String: Any?]? in
             if #available(iOS 16.0, *) {
+                #if compiler(>=5.7)
                 let verificationResult = try await AppTransaction.shared
 
                 let appTransaction: AppTransaction
@@ -287,6 +288,13 @@ public class ExpoIapModule: Module {
                 }
 
                 return result
+                #else
+                throw Exception(
+                    name: "ExpoIapModule",
+                    description: "getAppTransaction requires Xcode 15.0+ with iOS 16.0 SDK for compilation",
+                    code: IapErrorCode.unknown
+                )
+                #endif
             } else {
                 throw Exception(
                     name: "ExpoIapModule",

src/modules/ios.ts

@@ -264,10 +264,15 @@ export const presentCodeRedemptionSheetIOS = (): Promise<boolean> => {
  * Get app transaction information (iOS 16.0+).
  * AppTransaction represents the initial purchase that unlocked the app.
  * 
+ * NOTE: This function requires:
+ * - iOS 16.0 or later at runtime
+ * - Xcode 15.0+ with iOS 16.0 SDK for compilation
+ * 
  * @returns Promise resolving to the app transaction information or null if not available
- * @throws Error if called on non-iOS platform or iOS version < 16.0
+ * @throws Error if called on non-iOS platform, iOS version < 16.0, or compiled with older SDK
  * 
  * @platform iOS
+ * @since iOS 16.0
  */
 export const getAppTransactionIOS = (): Promise<AppTransactionIOS | null> => {
   return ExpoIapModule.getAppTransaction();