diff --git a/packages/in_app_purchase/in_app_purchase_storekit/CHANGELOG.md b/packages/in_app_purchase/in_app_purchase_storekit/CHANGELOG.md
index c19e4a826d..309510b3af 100644
--- a/packages/in_app_purchase/in_app_purchase_storekit/CHANGELOG.md
+++ b/packages/in_app_purchase/in_app_purchase_storekit/CHANGELOG.md
@@ -1,3 +1,8 @@
+## 0.3.12
+
+* Converts `refreshReceipt()`, `startObservingPaymentQueue()`, `stopObservingPaymentQueue()`, 
+`registerPaymentQueueDelegate()`, `removePaymentQueueDelegate()`, `showPriceConsentIfNeeded()` to pigeon.
+
 ## 0.3.11
 
 * Fixes SKError.userInfo not being nullable.
diff --git a/packages/in_app_purchase/in_app_purchase_storekit/darwin/Classes/InAppPurchasePlugin.m b/packages/in_app_purchase/in_app_purchase_storekit/darwin/Classes/InAppPurchasePlugin.m
index 8236653740..0a8b162bf1 100644
--- a/packages/in_app_purchase/in_app_purchase_storekit/darwin/Classes/InAppPurchasePlugin.m
+++ b/packages/in_app_purchase/in_app_purchase_storekit/darwin/Classes/InAppPurchasePlugin.m
@@ -87,30 +87,6 @@
   return self;
 }
 
-- (void)handleMethodCall:(FlutterMethodCall *)call result:(FlutterResult)result {
-  if ([@"-[InAppPurchasePlugin retrieveReceiptData:result:]" isEqualToString:call.method]) {
-    [self retrieveReceiptData:call result:result];
-  } else if ([@"-[InAppPurchasePlugin refreshReceipt:result:]" isEqualToString:call.method]) {
-    [self refreshReceipt:call result:result];
-  } else if ([@"-[SKPaymentQueue startObservingTransactionQueue]" isEqualToString:call.method]) {
-    [self startObservingPaymentQueue:result];
-  } else if ([@"-[SKPaymentQueue stopObservingTransactionQueue]" isEqualToString:call.method]) {
-    [self stopObservingPaymentQueue:result];
-#if TARGET_OS_IOS
-  } else if ([@"-[SKPaymentQueue registerDelegate]" isEqualToString:call.method]) {
-    [self registerPaymentQueueDelegate:result];
-#endif
-  } else if ([@"-[SKPaymentQueue removeDelegate]" isEqualToString:call.method]) {
-    [self removePaymentQueueDelegate:result];
-#if TARGET_OS_IOS
-  } else if ([@"-[SKPaymentQueue showPriceConsentIfNeeded]" isEqualToString:call.method]) {
-    [self showPriceConsentIfNeeded:result];
-#endif
-  } else {
-    result(FlutterMethodNotImplemented);
-  }
-}
-
 - (nullable NSNumber *)canMakePaymentsWithError:
     (FlutterError *_Nullable __autoreleasing *_Nonnull)error {
   return @([SKPaymentQueue canMakePayments]);
@@ -270,62 +246,61 @@
 #endif
 }
 
-- (void)retrieveReceiptData:(FlutterMethodCall *)call result:(FlutterResult)result {
-  FlutterError *error = nil;
-  NSString *receiptData = [self.receiptManager retrieveReceiptWithError:&error];
-  if (error) {
-    result(error);
-    return;
+- (nullable NSString *)retrieveReceiptDataWithError:
+    (FlutterError *_Nullable __autoreleasing *_Nonnull)error {
+  FlutterError *flutterError;
+  NSString *receiptData = [self.receiptManager retrieveReceiptWithError:&flutterError];
+  if (flutterError) {
+    *error = flutterError;
+    return nil;
   }
-  result(receiptData);
+  return receiptData;
 }
 
-- (void)refreshReceipt:(FlutterMethodCall *)call result:(FlutterResult)result {
-  NSDictionary *arguments = call.arguments;
+- (void)refreshReceiptReceiptProperties:(nullable NSDictionary *)receiptProperties
+                             completion:(nonnull void (^)(FlutterError *_Nullable))completion {
   SKReceiptRefreshRequest *request;
-  if (arguments) {
-    if (![arguments isKindOfClass:[NSDictionary class]]) {
-      result([FlutterError errorWithCode:@"storekit_invalid_argument"
-                                 message:@"Argument type of startRequest is not array"
-                                 details:call.arguments]);
-      return;
-    }
+  if (receiptProperties) {
+    // if recieptProperties is not null, this call is for testing.
     NSMutableDictionary *properties = [NSMutableDictionary new];
-    properties[SKReceiptPropertyIsExpired] = arguments[@"isExpired"];
-    properties[SKReceiptPropertyIsRevoked] = arguments[@"isRevoked"];
-    properties[SKReceiptPropertyIsVolumePurchase] = arguments[@"isVolumePurchase"];
+    properties[SKReceiptPropertyIsExpired] = receiptProperties[@"isExpired"];
+    properties[SKReceiptPropertyIsRevoked] = receiptProperties[@"isRevoked"];
+    properties[SKReceiptPropertyIsVolumePurchase] = receiptProperties[@"isVolumePurchase"];
     request = [self getRefreshReceiptRequest:properties];
   } else {
     request = [self getRefreshReceiptRequest:nil];
   }
+
   FIAPRequestHandler *handler = [[FIAPRequestHandler alloc] initWithRequest:request];
   [self.requestHandlers addObject:handler];
   __weak typeof(self) weakSelf = self;
   [handler startProductRequestWithCompletionHandler:^(SKProductsResponse *_Nullable response,
                                                       NSError *_Nullable error) {
+    FlutterError *requestError;
     if (error) {
-      result([FlutterError errorWithCode:@"storekit_refreshreceiptrequest_platform_error"
-                                 message:error.localizedDescription
-                                 details:error.description]);
-      return;
+      requestError = [FlutterError errorWithCode:@"storekit_refreshreceiptrequest_platform_error"
+                                         message:error.localizedDescription
+                                         details:error.description];
+      completion(requestError);
     }
-    result(nil);
+    completion(nil);
     [weakSelf.requestHandlers removeObject:handler];
   }];
 }
 
-- (void)startObservingPaymentQueue:(FlutterResult)result {
+- (void)startObservingPaymentQueueWithError:
+    (FlutterError *_Nullable __autoreleasing *_Nonnull)error {
   [_paymentQueueHandler startObservingPaymentQueue];
-  result(nil);
 }
 
-- (void)stopObservingPaymentQueue:(FlutterResult)result {
+- (void)stopObservingPaymentQueueWithError:
+    (FlutterError *_Nullable __autoreleasing *_Nonnull)error {
   [_paymentQueueHandler stopObservingPaymentQueue];
-  result(nil);
 }
 
+- (void)registerPaymentQueueDelegateWithError:
+    (FlutterError *_Nullable __autoreleasing *_Nonnull)error {
 #if TARGET_OS_IOS
-- (void)registerPaymentQueueDelegate:(FlutterResult)result {
   if (@available(iOS 13.0, *)) {
     _paymentQueueDelegateCallbackChannel = [FlutterMethodChannel
         methodChannelWithName:@"plugins.flutter.io/in_app_purchase_payment_queue_delegate"
@@ -335,27 +310,25 @@
         initWithMethodChannel:_paymentQueueDelegateCallbackChannel];
     _paymentQueueHandler.delegate = _paymentQueueDelegate;
   }
-  result(nil);
-}
 #endif
+}
 
-- (void)removePaymentQueueDelegate:(FlutterResult)result {
+- (void)removePaymentQueueDelegateWithError:
+    (FlutterError *_Nullable __autoreleasing *_Nonnull)error {
   if (@available(iOS 13.0, *)) {
     _paymentQueueHandler.delegate = nil;
   }
   _paymentQueueDelegate = nil;
   _paymentQueueDelegateCallbackChannel = nil;
-  result(nil);
 }
 
+- (void)showPriceConsentIfNeededWithError:(FlutterError *_Nullable __autoreleasing *_Nonnull)error {
 #if TARGET_OS_IOS
-- (void)showPriceConsentIfNeeded:(FlutterResult)result {
   if (@available(iOS 13.4, *)) {
     [_paymentQueueHandler showPriceConsentIfNeeded];
   }
-  result(nil);
-}
 #endif
+}
 
 - (id)getNonNullValueFromDictionary:(NSDictionary *)dictionary forKey:(NSString *)key {
   id value = dictionary[key];
diff --git a/packages/in_app_purchase/in_app_purchase_storekit/darwin/Classes/messages.g.h b/packages/in_app_purchase/in_app_purchase_storekit/darwin/Classes/messages.g.h
index 5d5b3a0c77..bc315e781c 100644
--- a/packages/in_app_purchase/in_app_purchase_storekit/darwin/Classes/messages.g.h
+++ b/packages/in_app_purchase/in_app_purchase_storekit/darwin/Classes/messages.g.h
@@ -1,7 +1,6 @@
 // Copyright 2013 The Flutter Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
-
 // Autogenerated from Pigeon (v16.0.4), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 
@@ -271,6 +270,14 @@ NSObject<FlutterMessageCodec> *InAppPurchaseAPIGetCodec(void);
 - (void)restoreTransactionsApplicationUserName:(nullable NSString *)applicationUserName
                                          error:(FlutterError *_Nullable *_Nonnull)error;
 - (void)presentCodeRedemptionSheetWithError:(FlutterError *_Nullable *_Nonnull)error;
+- (nullable NSString *)retrieveReceiptDataWithError:(FlutterError *_Nullable *_Nonnull)error;
+- (void)refreshReceiptReceiptProperties:(nullable NSDictionary<NSString *, id> *)receiptProperties
+                             completion:(void (^)(FlutterError *_Nullable))completion;
+- (void)startObservingPaymentQueueWithError:(FlutterError *_Nullable *_Nonnull)error;
+- (void)stopObservingPaymentQueueWithError:(FlutterError *_Nullable *_Nonnull)error;
+- (void)registerPaymentQueueDelegateWithError:(FlutterError *_Nullable *_Nonnull)error;
+- (void)removePaymentQueueDelegateWithError:(FlutterError *_Nullable *_Nonnull)error;
+- (void)showPriceConsentIfNeededWithError:(FlutterError *_Nullable *_Nonnull)error;
 @end
 
 extern void SetUpInAppPurchaseAPI(id<FlutterBinaryMessenger> binaryMessenger,
diff --git a/packages/in_app_purchase/in_app_purchase_storekit/darwin/Classes/messages.g.m b/packages/in_app_purchase/in_app_purchase_storekit/darwin/Classes/messages.g.m
index bbb5d6b67e..9588c883b8 100644
--- a/packages/in_app_purchase/in_app_purchase_storekit/darwin/Classes/messages.g.m
+++ b/packages/in_app_purchase/in_app_purchase_storekit/darwin/Classes/messages.g.m
@@ -1,7 +1,6 @@
 // Copyright 2013 The Flutter Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
-
 // Autogenerated from Pigeon (v16.0.4), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 
@@ -752,4 +751,147 @@ void SetUpInAppPurchaseAPI(id<FlutterBinaryMessenger> binaryMessenger,
       [channel setMessageHandler:nil];
     }
   }
+  {
+    FlutterBasicMessageChannel *channel = [[FlutterBasicMessageChannel alloc]
+           initWithName:
+               @"dev.flutter.pigeon.in_app_purchase_storekit.InAppPurchaseAPI.retrieveReceiptData"
+        binaryMessenger:binaryMessenger
+                  codec:InAppPurchaseAPIGetCodec()];
+    if (api) {
+      NSCAssert(
+          [api respondsToSelector:@selector(retrieveReceiptDataWithError:)],
+          @"InAppPurchaseAPI api (%@) doesn't respond to @selector(retrieveReceiptDataWithError:)",
+          api);
+      [channel setMessageHandler:^(id _Nullable message, FlutterReply callback) {
+        FlutterError *error;
+        NSString *output = [api retrieveReceiptDataWithError:&error];
+        callback(wrapResult(output, error));
+      }];
+    } else {
+      [channel setMessageHandler:nil];
+    }
+  }
+  {
+    FlutterBasicMessageChannel *channel = [[FlutterBasicMessageChannel alloc]
+           initWithName:
+               @"dev.flutter.pigeon.in_app_purchase_storekit.InAppPurchaseAPI.refreshReceipt"
+        binaryMessenger:binaryMessenger
+                  codec:InAppPurchaseAPIGetCodec()];
+    if (api) {
+      NSCAssert([api respondsToSelector:@selector(refreshReceiptReceiptProperties:completion:)],
+                @"InAppPurchaseAPI api (%@) doesn't respond to "
+                @"@selector(refreshReceiptReceiptProperties:completion:)",
+                api);
+      [channel setMessageHandler:^(id _Nullable message, FlutterReply callback) {
+        NSArray *args = message;
+        NSDictionary<NSString *, id> *arg_receiptProperties = GetNullableObjectAtIndex(args, 0);
+        [api refreshReceiptReceiptProperties:arg_receiptProperties
+                                  completion:^(FlutterError *_Nullable error) {
+                                    callback(wrapResult(nil, error));
+                                  }];
+      }];
+    } else {
+      [channel setMessageHandler:nil];
+    }
+  }
+  {
+    FlutterBasicMessageChannel *channel = [[FlutterBasicMessageChannel alloc]
+           initWithName:@"dev.flutter.pigeon.in_app_purchase_storekit.InAppPurchaseAPI."
+                        @"startObservingPaymentQueue"
+        binaryMessenger:binaryMessenger
+                  codec:InAppPurchaseAPIGetCodec()];
+    if (api) {
+      NSCAssert([api respondsToSelector:@selector(startObservingPaymentQueueWithError:)],
+                @"InAppPurchaseAPI api (%@) doesn't respond to "
+                @"@selector(startObservingPaymentQueueWithError:)",
+                api);
+      [channel setMessageHandler:^(id _Nullable message, FlutterReply callback) {
+        FlutterError *error;
+        [api startObservingPaymentQueueWithError:&error];
+        callback(wrapResult(nil, error));
+      }];
+    } else {
+      [channel setMessageHandler:nil];
+    }
+  }
+  {
+    FlutterBasicMessageChannel *channel = [[FlutterBasicMessageChannel alloc]
+           initWithName:@"dev.flutter.pigeon.in_app_purchase_storekit.InAppPurchaseAPI."
+                        @"stopObservingPaymentQueue"
+        binaryMessenger:binaryMessenger
+                  codec:InAppPurchaseAPIGetCodec()];
+    if (api) {
+      NSCAssert([api respondsToSelector:@selector(stopObservingPaymentQueueWithError:)],
+                @"InAppPurchaseAPI api (%@) doesn't respond to "
+                @"@selector(stopObservingPaymentQueueWithError:)",
+                api);
+      [channel setMessageHandler:^(id _Nullable message, FlutterReply callback) {
+        FlutterError *error;
+        [api stopObservingPaymentQueueWithError:&error];
+        callback(wrapResult(nil, error));
+      }];
+    } else {
+      [channel setMessageHandler:nil];
+    }
+  }
+  {
+    FlutterBasicMessageChannel *channel = [[FlutterBasicMessageChannel alloc]
+           initWithName:@"dev.flutter.pigeon.in_app_purchase_storekit.InAppPurchaseAPI."
+                        @"registerPaymentQueueDelegate"
+        binaryMessenger:binaryMessenger
+                  codec:InAppPurchaseAPIGetCodec()];
+    if (api) {
+      NSCAssert([api respondsToSelector:@selector(registerPaymentQueueDelegateWithError:)],
+                @"InAppPurchaseAPI api (%@) doesn't respond to "
+                @"@selector(registerPaymentQueueDelegateWithError:)",
+                api);
+      [channel setMessageHandler:^(id _Nullable message, FlutterReply callback) {
+        FlutterError *error;
+        [api registerPaymentQueueDelegateWithError:&error];
+        callback(wrapResult(nil, error));
+      }];
+    } else {
+      [channel setMessageHandler:nil];
+    }
+  }
+  {
+    FlutterBasicMessageChannel *channel = [[FlutterBasicMessageChannel alloc]
+           initWithName:@"dev.flutter.pigeon.in_app_purchase_storekit.InAppPurchaseAPI."
+                        @"removePaymentQueueDelegate"
+        binaryMessenger:binaryMessenger
+                  codec:InAppPurchaseAPIGetCodec()];
+    if (api) {
+      NSCAssert([api respondsToSelector:@selector(removePaymentQueueDelegateWithError:)],
+                @"InAppPurchaseAPI api (%@) doesn't respond to "
+                @"@selector(removePaymentQueueDelegateWithError:)",
+                api);
+      [channel setMessageHandler:^(id _Nullable message, FlutterReply callback) {
+        FlutterError *error;
+        [api removePaymentQueueDelegateWithError:&error];
+        callback(wrapResult(nil, error));
+      }];
+    } else {
+      [channel setMessageHandler:nil];
+    }
+  }
+  {
+    FlutterBasicMessageChannel *channel = [[FlutterBasicMessageChannel alloc]
+           initWithName:@"dev.flutter.pigeon.in_app_purchase_storekit.InAppPurchaseAPI."
+                        @"showPriceConsentIfNeeded"
+        binaryMessenger:binaryMessenger
+                  codec:InAppPurchaseAPIGetCodec()];
+    if (api) {
+      NSCAssert([api respondsToSelector:@selector(showPriceConsentIfNeededWithError:)],
+                @"InAppPurchaseAPI api (%@) doesn't respond to "
+                @"@selector(showPriceConsentIfNeededWithError:)",
+                api);
+      [channel setMessageHandler:^(id _Nullable message, FlutterReply callback) {
+        FlutterError *error;
+        [api showPriceConsentIfNeededWithError:&error];
+        callback(wrapResult(nil, error));
+      }];
+    } else {
+      [channel setMessageHandler:nil];
+    }
+  }
 }
diff --git a/packages/in_app_purchase/in_app_purchase_storekit/example/ios/Runner.xcodeproj/xcshareddata/xcschemes/Runner.xcscheme b/packages/in_app_purchase/in_app_purchase_storekit/example/ios/Runner.xcodeproj/xcshareddata/xcschemes/Runner.xcscheme
index 102a865d99..477131feb6 100644
--- a/packages/in_app_purchase/in_app_purchase_storekit/example/ios/Runner.xcodeproj/xcshareddata/xcschemes/Runner.xcscheme
+++ b/packages/in_app_purchase/in_app_purchase_storekit/example/ios/Runner.xcodeproj/xcshareddata/xcschemes/Runner.xcscheme
@@ -26,7 +26,8 @@
       buildConfiguration = "Debug"
       selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
       selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
-      shouldUseLaunchSchemeArgsEnv = "YES">
+      shouldUseLaunchSchemeArgsEnv = "YES"
+      codeCoverageEnabled = "YES">
       <MacroExpansion>
          <BuildableReference
             BuildableIdentifier = "primary"
diff --git a/packages/in_app_purchase/in_app_purchase_storekit/example/shared/RunnerTests/InAppPurchasePluginTests.m b/packages/in_app_purchase/in_app_purchase_storekit/example/shared/RunnerTests/InAppPurchasePluginTests.m
index d53301e54c..1c0f734bc0 100644
--- a/packages/in_app_purchase/in_app_purchase_storekit/example/shared/RunnerTests/InAppPurchasePluginTests.m
+++ b/packages/in_app_purchase/in_app_purchase_storekit/example/shared/RunnerTests/InAppPurchasePluginTests.m
@@ -26,20 +26,6 @@
 - (void)tearDown {
 }
 
-- (void)testInvalidMethodCall {
-  XCTestExpectation *expectation =
-      [self expectationWithDescription:@"expect result to be not implemented"];
-  FlutterMethodCall *call = [FlutterMethodCall methodCallWithMethodName:@"invalid" arguments:NULL];
-  __block id result;
-  [self.plugin handleMethodCall:call
-                         result:^(id r) {
-                           [expectation fulfill];
-                           result = r;
-                         }];
-  [self waitForExpectations:@[ expectation ] timeout:5];
-  XCTAssertEqual(result, FlutterMethodNotImplemented);
-}
-
 - (void)testCanMakePayments {
   FlutterError *error;
   NSNumber *result = [self.plugin canMakePaymentsWithError:&error];
@@ -299,17 +285,8 @@
 }
 
 - (void)testRetrieveReceiptDataSuccess {
-  XCTestExpectation *expectation = [self expectationWithDescription:@"receipt data retrieved"];
-  FlutterMethodCall *call = [FlutterMethodCall
-      methodCallWithMethodName:@"-[InAppPurchasePlugin retrieveReceiptData:result:]"
-                     arguments:nil];
-  __block NSDictionary *result;
-  [self.plugin handleMethodCall:call
-                         result:^(id r) {
-                           result = r;
-                           [expectation fulfill];
-                         }];
-  [self waitForExpectations:@[ expectation ] timeout:5];
+  FlutterError *error;
+  NSString *result = [self.plugin retrieveReceiptDataWithError:&error];
   XCTAssertNotNil(result);
   XCTAssert([result isKindOfClass:[NSString class]]);
 }
@@ -317,71 +294,47 @@
 - (void)testRetrieveReceiptDataNil {
   NSBundle *mockBundle = OCMPartialMock([NSBundle mainBundle]);
   OCMStub(mockBundle.appStoreReceiptURL).andReturn(nil);
-  XCTestExpectation *expectation = [self expectationWithDescription:@"nil receipt data retrieved"];
-  FlutterMethodCall *call = [FlutterMethodCall
-      methodCallWithMethodName:@"-[InAppPurchasePlugin retrieveReceiptData:result:]"
-                     arguments:nil];
-  __block NSDictionary *result;
-  [self.plugin handleMethodCall:call
-                         result:^(id r) {
-                           result = r;
-                           [expectation fulfill];
-                         }];
-  [self waitForExpectations:@[ expectation ] timeout:5];
+  FlutterError *error;
+  NSString *result = [self.plugin retrieveReceiptDataWithError:&error];
   XCTAssertNil(result);
 }
 
 - (void)testRetrieveReceiptDataError {
-  XCTestExpectation *expectation = [self expectationWithDescription:@"receipt data retrieved"];
-  FlutterMethodCall *call = [FlutterMethodCall
-      methodCallWithMethodName:@"-[InAppPurchasePlugin retrieveReceiptData:result:]"
-                     arguments:nil];
-  __block NSDictionary *result;
   self.receiptManagerStub.returnError = YES;
-  [self.plugin handleMethodCall:call
-                         result:^(id r) {
-                           result = r;
-                           [expectation fulfill];
-                         }];
-  [self waitForExpectations:@[ expectation ] timeout:5];
-  XCTAssertNotNil(result);
-  XCTAssert([result isKindOfClass:[FlutterError class]]);
-  NSDictionary *details = ((FlutterError *)result).details;
+
+  FlutterError *error;
+  NSString *result = [self.plugin retrieveReceiptDataWithError:&error];
+
+  XCTAssertNil(result);
+  XCTAssertNotNil(error);
+  NSDictionary *details = error.details;
   XCTAssertNotNil(details[@"error"]);
   NSNumber *errorCode = (NSNumber *)details[@"error"][@"code"];
   XCTAssertEqual(errorCode, [NSNumber numberWithInteger:99]);
 }
 
 - (void)testRefreshReceiptRequest {
-  XCTestExpectation *expectation = [self expectationWithDescription:@"expect success"];
-  FlutterMethodCall *call =
-      [FlutterMethodCall methodCallWithMethodName:@"-[InAppPurchasePlugin refreshReceipt:result:]"
-                                        arguments:nil];
-  __block BOOL result = NO;
-  [self.plugin handleMethodCall:call
-                         result:^(id r) {
-                           result = YES;
-                           [expectation fulfill];
-                         }];
+  XCTestExpectation *expectation =
+      [self expectationWithDescription:@"completion handler successfully called"];
+  [self.plugin refreshReceiptReceiptProperties:nil
+                                    completion:^(FlutterError *_Nullable error) {
+                                      [expectation fulfill];
+                                    }];
   [self waitForExpectations:@[ expectation ] timeout:5];
-  XCTAssertTrue(result);
 }
 
+/// presentCodeRedemptionSheetWithError:error is only available on iOS
+#if TARGET_OS_IOS
 - (void)testPresentCodeRedemptionSheet {
-  XCTestExpectation *expectation =
-      [self expectationWithDescription:@"expect successfully present Code Redemption Sheet"];
-  FlutterMethodCall *call = [FlutterMethodCall
-      methodCallWithMethodName:@"-[InAppPurchasePlugin presentCodeRedemptionSheet:result:]"
-                     arguments:nil];
-  __block BOOL callbackInvoked = NO;
-  [self.plugin handleMethodCall:call
-                         result:^(id r) {
-                           callbackInvoked = YES;
-                           [expectation fulfill];
-                         }];
-  [self waitForExpectations:@[ expectation ] timeout:5];
-  XCTAssertTrue(callbackInvoked);
+  FIAPaymentQueueHandler *mockHandler = OCMClassMock([FIAPaymentQueueHandler class]);
+  self.plugin.paymentQueueHandler = mockHandler;
+
+  FlutterError *error;
+  [self.plugin presentCodeRedemptionSheetWithError:&error];
+
+  OCMVerify(times(1), [mockHandler presentCodeRedemptionSheet]);
 }
+#endif
 
 - (void)testGetPendingTransactions {
   SKPaymentQueue *mockQueue = OCMClassMock(SKPaymentQueue.class);
@@ -420,48 +373,28 @@
 }
 
 - (void)testStartObservingPaymentQueue {
-  XCTestExpectation *expectation =
-      [self expectationWithDescription:@"Should return success result"];
-  FlutterMethodCall *startCall = [FlutterMethodCall
-      methodCallWithMethodName:@"-[SKPaymentQueue startObservingTransactionQueue]"
-                     arguments:nil];
   FIAPaymentQueueHandler *mockHandler = OCMClassMock([FIAPaymentQueueHandler class]);
   self.plugin.paymentQueueHandler = mockHandler;
-  [self.plugin handleMethodCall:startCall
-                         result:^(id _Nullable result) {
-                           XCTAssertNil(result);
-                           [expectation fulfill];
-                         }];
 
-  [self waitForExpectations:@[ expectation ] timeout:5];
+  FlutterError *error;
+  [self.plugin startObservingPaymentQueueWithError:&error];
+
   OCMVerify(times(1), [mockHandler startObservingPaymentQueue]);
 }
 
 - (void)testStopObservingPaymentQueue {
-  XCTestExpectation *expectation =
-      [self expectationWithDescription:@"Should return success result"];
-  FlutterMethodCall *stopCall =
-      [FlutterMethodCall methodCallWithMethodName:@"-[SKPaymentQueue stopObservingTransactionQueue]"
-                                        arguments:nil];
   FIAPaymentQueueHandler *mockHandler = OCMClassMock([FIAPaymentQueueHandler class]);
   self.plugin.paymentQueueHandler = mockHandler;
-  [self.plugin handleMethodCall:stopCall
-                         result:^(id _Nullable result) {
-                           XCTAssertNil(result);
-                           [expectation fulfill];
-                         }];
 
-  [self waitForExpectations:@[ expectation ] timeout:5];
+  FlutterError *error;
+  [self.plugin stopObservingPaymentQueueWithError:&error];
+
   OCMVerify(times(1), [mockHandler stopObservingPaymentQueue]);
 }
 
 #if TARGET_OS_IOS
 - (void)testRegisterPaymentQueueDelegate {
   if (@available(iOS 13, *)) {
-    FlutterMethodCall *call =
-        [FlutterMethodCall methodCallWithMethodName:@"-[SKPaymentQueue registerDelegate]"
-                                          arguments:nil];
-
     self.plugin.paymentQueueHandler =
         [[FIAPaymentQueueHandler alloc] initWithQueue:[SKPaymentQueueStub new]
                                   transactionsUpdated:nil
@@ -475,9 +408,8 @@
     // Verify the delegate is nil before we register one.
     XCTAssertNil(self.plugin.paymentQueueHandler.delegate);
 
-    [self.plugin handleMethodCall:call
-                           result:^(id r){
-                           }];
+    FlutterError *error;
+    [self.plugin registerPaymentQueueDelegateWithError:&error];
 
     // Verify the delegate is not nil after we registered one.
     XCTAssertNotNil(self.plugin.paymentQueueHandler.delegate);
@@ -487,10 +419,6 @@
 
 - (void)testRemovePaymentQueueDelegate {
   if (@available(iOS 13, *)) {
-    FlutterMethodCall *call =
-        [FlutterMethodCall methodCallWithMethodName:@"-[SKPaymentQueue removeDelegate]"
-                                          arguments:nil];
-
     self.plugin.paymentQueueHandler =
         [[FIAPaymentQueueHandler alloc] initWithQueue:[SKPaymentQueueStub new]
                                   transactionsUpdated:nil
@@ -505,9 +433,8 @@
     // Verify the delegate is not nil before removing it.
     XCTAssertNotNil(self.plugin.paymentQueueHandler.delegate);
 
-    [self.plugin handleMethodCall:call
-                           result:^(id r){
-                           }];
+    FlutterError *error;
+    [self.plugin removePaymentQueueDelegateWithError:&error];
 
     // Verify the delegate is nill after removing it.
     XCTAssertNil(self.plugin.paymentQueueHandler.delegate);
@@ -516,16 +443,11 @@
 
 #if TARGET_OS_IOS
 - (void)testShowPriceConsentIfNeeded {
-  FlutterMethodCall *call =
-      [FlutterMethodCall methodCallWithMethodName:@"-[SKPaymentQueue showPriceConsentIfNeeded]"
-                                        arguments:nil];
-
   FIAPaymentQueueHandler *mockQueueHandler = OCMClassMock(FIAPaymentQueueHandler.class);
   self.plugin.paymentQueueHandler = mockQueueHandler;
 
-  [self.plugin handleMethodCall:call
-                         result:^(id r){
-                         }];
+  FlutterError *error;
+  [self.plugin showPriceConsentIfNeededWithError:&error];
 
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wpartial-availability"
diff --git a/packages/in_app_purchase/in_app_purchase_storekit/lib/src/messages.g.dart b/packages/in_app_purchase/in_app_purchase_storekit/lib/src/messages.g.dart
index 27a38c9e57..7ce35bded2 100644
--- a/packages/in_app_purchase/in_app_purchase_storekit/lib/src/messages.g.dart
+++ b/packages/in_app_purchase/in_app_purchase_storekit/lib/src/messages.g.dart
@@ -1,3 +1,6 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
 // Autogenerated from Pigeon (v16.0.4), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import, no_leading_underscores_for_local_identifiers
@@ -788,4 +791,173 @@ class InAppPurchaseAPI {
       return;
     }
   }
+
+  Future<String?> retrieveReceiptData() async {
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.in_app_purchase_storekit.InAppPurchaseAPI.retrieveReceiptData';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(null) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return (__pigeon_replyList[0] as String?);
+    }
+  }
+
+  Future<void> refreshReceipt(
+      {Map<String?, Object?>? receiptProperties}) async {
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.in_app_purchase_storekit.InAppPurchaseAPI.refreshReceipt';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList = await __pigeon_channel
+        .send(<Object?>[receiptProperties]) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return;
+    }
+  }
+
+  Future<void> startObservingPaymentQueue() async {
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.in_app_purchase_storekit.InAppPurchaseAPI.startObservingPaymentQueue';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(null) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return;
+    }
+  }
+
+  Future<void> stopObservingPaymentQueue() async {
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.in_app_purchase_storekit.InAppPurchaseAPI.stopObservingPaymentQueue';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(null) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return;
+    }
+  }
+
+  Future<void> registerPaymentQueueDelegate() async {
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.in_app_purchase_storekit.InAppPurchaseAPI.registerPaymentQueueDelegate';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(null) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return;
+    }
+  }
+
+  Future<void> removePaymentQueueDelegate() async {
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.in_app_purchase_storekit.InAppPurchaseAPI.removePaymentQueueDelegate';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(null) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return;
+    }
+  }
+
+  Future<void> showPriceConsentIfNeeded() async {
+    const String __pigeon_channelName =
+        'dev.flutter.pigeon.in_app_purchase_storekit.InAppPurchaseAPI.showPriceConsentIfNeeded';
+    final BasicMessageChannel<Object?> __pigeon_channel =
+        BasicMessageChannel<Object?>(
+      __pigeon_channelName,
+      pigeonChannelCodec,
+      binaryMessenger: __pigeon_binaryMessenger,
+    );
+    final List<Object?>? __pigeon_replyList =
+        await __pigeon_channel.send(null) as List<Object?>?;
+    if (__pigeon_replyList == null) {
+      throw _createConnectionError(__pigeon_channelName);
+    } else if (__pigeon_replyList.length > 1) {
+      throw PlatformException(
+        code: __pigeon_replyList[0]! as String,
+        message: __pigeon_replyList[1] as String?,
+        details: __pigeon_replyList[2],
+      );
+    } else {
+      return;
+    }
+  }
 }
diff --git a/packages/in_app_purchase/in_app_purchase_storekit/lib/src/store_kit_wrappers/sk_payment_queue_wrapper.dart b/packages/in_app_purchase/in_app_purchase_storekit/lib/src/store_kit_wrappers/sk_payment_queue_wrapper.dart
index dd5571a7af..8f1af1c640 100644
--- a/packages/in_app_purchase/in_app_purchase_storekit/lib/src/store_kit_wrappers/sk_payment_queue_wrapper.dart
+++ b/packages/in_app_purchase/in_app_purchase_storekit/lib/src/store_kit_wrappers/sk_payment_queue_wrapper.dart
@@ -86,16 +86,16 @@ class SKPaymentQueueWrapper {
   ///
   /// Call this method when the first listener is subscribed to the
   /// [InAppPurchaseStoreKitPlatform.purchaseStream].
-  Future<void> startObservingTransactionQueue() => channel
-      .invokeMethod<void>('-[SKPaymentQueue startObservingTransactionQueue]');
+  Future<void> startObservingTransactionQueue() =>
+      _hostApi.startObservingPaymentQueue();
 
   /// Instructs the iOS implementation to remove the transaction observer and
   /// stop listening to it.
   ///
   /// Call this when there are no longer any listeners subscribed to the
   /// [InAppPurchaseStoreKitPlatform.purchaseStream].
-  Future<void> stopObservingTransactionQueue() => channel
-      .invokeMethod<void>('-[SKPaymentQueue stopObservingTransactionQueue]');
+  Future<void> stopObservingTransactionQueue() =>
+      _hostApi.stopObservingPaymentQueue();
 
   /// Sets an implementation of the [SKPaymentQueueDelegateWrapper].
   ///
@@ -109,10 +109,10 @@ class SKPaymentQueueWrapper {
   /// default behaviour will apply (see [documentation](https://developer.apple.com/documentation/storekit/skpaymentqueue/3182429-delegate?language=objc)).
   Future<void> setDelegate(SKPaymentQueueDelegateWrapper? delegate) async {
     if (delegate == null) {
-      await channel.invokeMethod<void>('-[SKPaymentQueue removeDelegate]');
+      await _hostApi.removePaymentQueueDelegate();
       paymentQueueDelegateChannel.setMethodCallHandler(null);
     } else {
-      await channel.invokeMethod<void>('-[SKPaymentQueue registerDelegate]');
+      await _hostApi.registerPaymentQueueDelegate();
       paymentQueueDelegateChannel
           .setMethodCallHandler(handlePaymentQueueDelegateCallbacks);
     }
@@ -207,8 +207,7 @@ class SKPaymentQueueWrapper {
   ///
   /// See documentation of StoreKit's [`-[SKPaymentQueue showPriceConsentIfNeeded]`](https://developer.apple.com/documentation/storekit/skpaymentqueue/3521327-showpriceconsentifneeded?language=objc).
   Future<void> showPriceConsentIfNeeded() async {
-    await channel
-        .invokeMethod<void>('-[SKPaymentQueue showPriceConsentIfNeeded]');
+    await _hostApi.showPriceConsentIfNeeded();
   }
 
   /// Triage a method channel call from the platform and triggers the correct observer method.
@@ -354,7 +353,7 @@ class SKError {
   ///
   /// Any key of the map must be a valid [NSErrorUserInfoKey](https://developer.apple.com/documentation/foundation/nserroruserinfokey?language=objc).
   @JsonKey(defaultValue: <String, dynamic>{})
-  final Map<String?, Object?> userInfo;
+  final Map<String?, Object?>? userInfo;
 
   @override
   bool operator ==(Object other) {
diff --git a/packages/in_app_purchase/in_app_purchase_storekit/lib/src/store_kit_wrappers/sk_receipt_manager.dart b/packages/in_app_purchase/in_app_purchase_storekit/lib/src/store_kit_wrappers/sk_receipt_manager.dart
index b31a3d59c1..f61105aa21 100644
--- a/packages/in_app_purchase/in_app_purchase_storekit/lib/src/store_kit_wrappers/sk_receipt_manager.dart
+++ b/packages/in_app_purchase/in_app_purchase_storekit/lib/src/store_kit_wrappers/sk_receipt_manager.dart
@@ -4,7 +4,9 @@
 
 import 'dart:async';
 
-import '../channel.dart';
+import '../messages.g.dart';
+
+InAppPurchaseAPI _hostApi = InAppPurchaseAPI();
 
 // ignore: avoid_classes_with_only_static_members
 /// This class contains static methods to manage StoreKit receipts.
@@ -17,8 +19,6 @@ class SKReceiptManager {
   /// For more details on how to validate the receipt data, you can refer to Apple's document about [`About Receipt Validation`](https://developer.apple.com/library/archive/releasenotes/General/ValidateAppStoreReceipt/Introduction.html#//apple_ref/doc/uid/TP40010573-CH105-SW1).
   /// If the receipt is invalid or missing, you can use [SKRequestMaker.startRefreshReceiptRequest] to request a new receipt.
   static Future<String> retrieveReceiptData() async {
-    return (await channel.invokeMethod<String>(
-            '-[InAppPurchasePlugin retrieveReceiptData:result:]')) ??
-        '';
+    return (await _hostApi.retrieveReceiptData()) ?? '';
   }
 }
diff --git a/packages/in_app_purchase/in_app_purchase_storekit/lib/src/store_kit_wrappers/sk_request_maker.dart b/packages/in_app_purchase/in_app_purchase_storekit/lib/src/store_kit_wrappers/sk_request_maker.dart
index 2dc2ad7bae..5a16f261cd 100644
--- a/packages/in_app_purchase/in_app_purchase_storekit/lib/src/store_kit_wrappers/sk_request_maker.dart
+++ b/packages/in_app_purchase/in_app_purchase_storekit/lib/src/store_kit_wrappers/sk_request_maker.dart
@@ -6,7 +6,6 @@ import 'dart:async';
 
 import 'package:flutter/services.dart';
 
-import '../channel.dart';
 import '../messages.g.dart';
 import 'sk_product_wrapper.dart';
 
@@ -54,9 +53,6 @@ class SKRequestMaker {
   /// * isVolumePurchase: whether the receipt is a Volume Purchase Plan receipt.
   Future<void> startRefreshReceiptRequest(
       {Map<String, dynamic>? receiptProperties}) {
-    return channel.invokeMethod<void>(
-      '-[InAppPurchasePlugin refreshReceipt:result:]',
-      receiptProperties,
-    );
+    return _hostApi.refreshReceipt(receiptProperties: receiptProperties);
   }
 }
diff --git a/packages/in_app_purchase/in_app_purchase_storekit/pigeons/copyright.txt b/packages/in_app_purchase/in_app_purchase_storekit/pigeons/copyright.txt
index e69de29bb2..fb682b1ab9 100644
--- a/packages/in_app_purchase/in_app_purchase_storekit/pigeons/copyright.txt
+++ b/packages/in_app_purchase/in_app_purchase_storekit/pigeons/copyright.txt
@@ -0,0 +1,3 @@
+Copyright 2013 The Flutter Authors. All rights reserved.
+Use of this source code is governed by a BSD-style license that can be
+found in the LICENSE file.
\ No newline at end of file
diff --git a/packages/in_app_purchase/in_app_purchase_storekit/pigeons/messages.dart b/packages/in_app_purchase/in_app_purchase_storekit/pigeons/messages.dart
index c5d3526504..fe1042c803 100644
--- a/packages/in_app_purchase/in_app_purchase_storekit/pigeons/messages.dart
+++ b/packages/in_app_purchase/in_app_purchase_storekit/pigeons/messages.dart
@@ -243,4 +243,19 @@ abstract class InAppPurchaseAPI {
   void restoreTransactions(String? applicationUserName);
 
   void presentCodeRedemptionSheet();
+
+  String? retrieveReceiptData();
+
+  @async
+  void refreshReceipt({Map<String, Object?>? receiptProperties});
+
+  void startObservingPaymentQueue();
+
+  void stopObservingPaymentQueue();
+
+  void registerPaymentQueueDelegate();
+
+  void removePaymentQueueDelegate();
+
+  void showPriceConsentIfNeeded();
 }
diff --git a/packages/in_app_purchase/in_app_purchase_storekit/pubspec.yaml b/packages/in_app_purchase/in_app_purchase_storekit/pubspec.yaml
index 920873e652..ee7422b100 100644
--- a/packages/in_app_purchase/in_app_purchase_storekit/pubspec.yaml
+++ b/packages/in_app_purchase/in_app_purchase_storekit/pubspec.yaml
@@ -2,7 +2,7 @@ name: in_app_purchase_storekit
 description: An implementation for the iOS and macOS platforms of the Flutter `in_app_purchase` plugin. This uses the StoreKit Framework.
 repository: https://github.com/flutter/packages/tree/main/packages/in_app_purchase/in_app_purchase_storekit
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+in_app_purchase%22
-version: 0.3.11
+version: 0.3.12
 
 environment:
   sdk: ^3.2.3
diff --git a/packages/in_app_purchase/in_app_purchase_storekit/test/fakes/fake_storekit_platform.dart b/packages/in_app_purchase/in_app_purchase_storekit/test/fakes/fake_storekit_platform.dart
index 48db0847bf..8fff5754eb 100644
--- a/packages/in_app_purchase/in_app_purchase_storekit/test/fakes/fake_storekit_platform.dart
+++ b/packages/in_app_purchase/in_app_purchase_storekit/test/fakes/fake_storekit_platform.dart
@@ -5,7 +5,6 @@
 import 'package:flutter/services.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:in_app_purchase_storekit/in_app_purchase_storekit.dart';
-import 'package:in_app_purchase_storekit/src/channel.dart';
 import 'package:in_app_purchase_storekit/src/messages.g.dart';
 import 'package:in_app_purchase_storekit/store_kit_wrappers.dart';
 
@@ -13,11 +12,6 @@ import '../store_kit_wrappers/sk_test_stub_objects.dart';
 import '../test_api.g.dart';
 
 class FakeStoreKitPlatform implements TestInAppPurchaseApi {
-  FakeStoreKitPlatform() {
-    TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
-        .setMockMethodCallHandler(channel, onMethodCall);
-  }
-
   // pre-configured store information
   String? receiptData;
   late Set<String> validProductIDs;
@@ -32,6 +26,7 @@ class FakeStoreKitPlatform implements TestInAppPurchaseApi {
   SKError? testRestoredError;
   bool queueIsActive = false;
   Map<String, dynamic> discountReceived = <String, dynamic>{};
+  bool isPaymentQueueDelegateRegistered = false;
 
   void reset() {
     transactionList = <SKPaymentTransactionWrapper>[];
@@ -57,6 +52,7 @@ class FakeStoreKitPlatform implements TestInAppPurchaseApi {
     testRestoredError = null;
     queueIsActive = false;
     discountReceived = <String, dynamic>{};
+    isPaymentQueueDelegateRegistered = false;
   }
 
   SKPaymentTransactionWrapper createPendingTransaction(String id,
@@ -120,25 +116,6 @@ class FakeStoreKitPlatform implements TestInAppPurchaseApi {
         transactionIdentifier: transactionId);
   }
 
-  Future<dynamic> onMethodCall(MethodCall call) {
-    switch (call.method) {
-      case '-[InAppPurchasePlugin retrieveReceiptData:result:]':
-        if (receiptData != null) {
-          return Future<String>.value(receiptData!);
-        } else {
-          throw PlatformException(code: 'no_receipt_data');
-        }
-      case '-[InAppPurchasePlugin refreshReceipt:result:]':
-        receiptData = 'refreshed receipt data';
-        return Future<void>.sync(() {});
-      case '-[SKPaymentQueue startObservingTransactionQueue]':
-        queueIsActive = true;
-      case '-[SKPaymentQueue stopObservingTransactionQueue]':
-        queueIsActive = false;
-    }
-    return Future<void>.sync(() {});
-  }
-
   @override
   bool canMakePayments() {
     return true;
@@ -246,4 +223,42 @@ class FakeStoreKitPlatform implements TestInAppPurchaseApi {
     return Future<SKProductsResponseMessage>.value(
         SkProductResponseWrapper.convertToPigeon(response));
   }
+
+  @override
+  Future<void> refreshReceipt({Map<String?, dynamic>? receiptProperties}) {
+    receiptData = 'refreshed receipt data';
+    return Future<void>.sync(() {});
+  }
+
+  @override
+  void registerPaymentQueueDelegate() {
+    isPaymentQueueDelegateRegistered = true;
+  }
+
+  @override
+  void removePaymentQueueDelegate() {
+    isPaymentQueueDelegateRegistered = false;
+  }
+
+  @override
+  String retrieveReceiptData() {
+    if (receiptData != null) {
+      return receiptData!;
+    } else {
+      throw PlatformException(code: 'no_receipt_data');
+    }
+  }
+
+  @override
+  void showPriceConsentIfNeeded() {}
+
+  @override
+  void startObservingPaymentQueue() {
+    queueIsActive = true;
+  }
+
+  @override
+  void stopObservingPaymentQueue() {
+    queueIsActive = false;
+  }
 }
diff --git a/packages/in_app_purchase/in_app_purchase_storekit/test/in_app_purchase_storekit_platform_addtion_test.dart b/packages/in_app_purchase/in_app_purchase_storekit/test/in_app_purchase_storekit_platform_addtion_test.dart
index 99fd49d03a..40068db75a 100644
--- a/packages/in_app_purchase/in_app_purchase_storekit/test/in_app_purchase_storekit_platform_addtion_test.dart
+++ b/packages/in_app_purchase/in_app_purchase_storekit/test/in_app_purchase_storekit_platform_addtion_test.dart
@@ -2,7 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'package:flutter/services.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:in_app_purchase_platform_interface/in_app_purchase_platform_interface.dart';
 import 'package:in_app_purchase_storekit/in_app_purchase_storekit.dart';
@@ -17,9 +16,6 @@ void main() {
 
   setUpAll(() {
     TestInAppPurchaseApi.setup(fakeStoreKitPlatform);
-    TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
-        .setMockMethodCallHandler(
-            SystemChannels.platform, fakeStoreKitPlatform.onMethodCall);
   });
 
   group('present code redemption sheet', () {
diff --git a/packages/in_app_purchase/in_app_purchase_storekit/test/in_app_purchase_storekit_platform_test.dart b/packages/in_app_purchase/in_app_purchase_storekit/test/in_app_purchase_storekit_platform_test.dart
index 278a691844..e268c23bda 100644
--- a/packages/in_app_purchase/in_app_purchase_storekit/test/in_app_purchase_storekit_platform_test.dart
+++ b/packages/in_app_purchase/in_app_purchase_storekit/test/in_app_purchase_storekit_platform_test.dart
@@ -23,9 +23,6 @@ void main() {
 
   setUpAll(() {
     TestInAppPurchaseApi.setup(fakeStoreKitPlatform);
-    TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
-        .setMockMethodCallHandler(
-            SystemChannels.platform, fakeStoreKitPlatform.onMethodCall);
   });
 
   setUp(() {
diff --git a/packages/in_app_purchase/in_app_purchase_storekit/test/store_kit_wrappers/sk_methodchannel_apis_test.dart b/packages/in_app_purchase/in_app_purchase_storekit/test/store_kit_wrappers/sk_methodchannel_apis_test.dart
index 704be83c8e..82775f6b2e 100644
--- a/packages/in_app_purchase/in_app_purchase_storekit/test/store_kit_wrappers/sk_methodchannel_apis_test.dart
+++ b/packages/in_app_purchase/in_app_purchase_storekit/test/store_kit_wrappers/sk_methodchannel_apis_test.dart
@@ -4,7 +4,6 @@
 
 import 'package:flutter/services.dart';
 import 'package:flutter_test/flutter_test.dart';
-import 'package:in_app_purchase_storekit/src/channel.dart';
 import 'package:in_app_purchase_storekit/src/messages.g.dart';
 import 'package:in_app_purchase_storekit/store_kit_wrappers.dart';
 import '../test_api.g.dart';
@@ -17,9 +16,6 @@ void main() {
 
   setUpAll(() {
     TestInAppPurchaseApi.setup(fakeStoreKitPlatform);
-    TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
-        .setMockMethodCallHandler(
-            SystemChannels.platform, fakeStoreKitPlatform.onMethodCall);
   });
 
   setUp(() {});
@@ -76,10 +72,10 @@ void main() {
     });
 
     test('refreshed receipt', () async {
-      final int receiptCountBefore = fakeStoreKitPlatform.refreshReceipt;
+      final int receiptCountBefore = fakeStoreKitPlatform.refreshReceiptCount;
       await SKRequestMaker().startRefreshReceiptRequest(
           receiptProperties: <String, dynamic>{'isExpired': true});
-      expect(fakeStoreKitPlatform.refreshReceipt, receiptCountBefore + 1);
+      expect(fakeStoreKitPlatform.refreshReceiptCount, receiptCountBefore + 1);
       expect(fakeStoreKitPlatform.refreshReceiptParam,
           <String, dynamic>{'isExpired': true});
     });
@@ -175,9 +171,9 @@ void main() {
     });
 
     test('showPriceConsentIfNeeded should call methodChannel', () async {
-      expect(fakeStoreKitPlatform.showPriceConsentIfNeeded, false);
+      expect(fakeStoreKitPlatform.showPriceConsent, false);
       await SKPaymentQueueWrapper().showPriceConsentIfNeeded();
-      expect(fakeStoreKitPlatform.showPriceConsentIfNeeded, true);
+      expect(fakeStoreKitPlatform.showPriceConsent, true);
     });
   });
 
@@ -192,10 +188,6 @@ void main() {
 }
 
 class FakeStoreKitPlatform implements TestInAppPurchaseApi {
-  FakeStoreKitPlatform() {
-    TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
-        .setMockMethodCallHandler(channel, onMethodCall);
-  }
   // get product request
   List<dynamic> startProductRequestParam = <dynamic>[];
   bool getProductRequestFailTest = false;
@@ -205,7 +197,7 @@ class FakeStoreKitPlatform implements TestInAppPurchaseApi {
   bool getReceiptFailTest = false;
 
   // refresh receipt request
-  int refreshReceipt = 0;
+  int refreshReceiptCount = 0;
   late Map<String, dynamic> refreshReceiptParam;
 
   // payment queue
@@ -217,7 +209,7 @@ class FakeStoreKitPlatform implements TestInAppPurchaseApi {
   bool presentCodeRedemption = false;
 
   // show price consent sheet
-  bool showPriceConsentIfNeeded = false;
+  bool showPriceConsent = false;
 
   // indicate if the payment queue delegate is registered
   bool isPaymentQueueDelegateRegistered = false;
@@ -225,39 +217,6 @@ class FakeStoreKitPlatform implements TestInAppPurchaseApi {
   // Listen to purchase updates
   bool? queueIsActive;
 
-  Future<dynamic> onMethodCall(MethodCall call) {
-    switch (call.method) {
-      // request makers
-      case '-[InAppPurchasePlugin refreshReceipt:result:]':
-        refreshReceipt++;
-        refreshReceiptParam = Map.castFrom<dynamic, dynamic, String, dynamic>(
-            call.arguments as Map<dynamic, dynamic>);
-        return Future<void>.sync(() {});
-      // receipt manager
-      case '-[InAppPurchasePlugin retrieveReceiptData:result:]':
-        if (getReceiptFailTest) {
-          throw Exception('some arbitrary error');
-        }
-        return Future<String>.value('receipt data');
-      case '-[SKPaymentQueue startObservingTransactionQueue]':
-        queueIsActive = true;
-        return Future<void>.sync(() {});
-      case '-[SKPaymentQueue stopObservingTransactionQueue]':
-        queueIsActive = false;
-        return Future<void>.sync(() {});
-      case '-[SKPaymentQueue registerDelegate]':
-        isPaymentQueueDelegateRegistered = true;
-        return Future<void>.sync(() {});
-      case '-[SKPaymentQueue removeDelegate]':
-        isPaymentQueueDelegateRegistered = false;
-        return Future<void>.sync(() {});
-      case '-[SKPaymentQueue showPriceConsentIfNeeded]':
-        showPriceConsentIfNeeded = true;
-        return Future<void>.sync(() {});
-    }
-    return Future<dynamic>.error('method not mocked');
-  }
-
   @override
   void addPayment(Map<String?, Object?> paymentMap) {
     payments
@@ -304,6 +263,47 @@ class FakeStoreKitPlatform implements TestInAppPurchaseApi {
     }
     return Future<SKProductsResponseMessage>.value(dummyProductResponseMessage);
   }
+
+  @override
+  void registerPaymentQueueDelegate() {
+    isPaymentQueueDelegateRegistered = true;
+  }
+
+  @override
+  void removePaymentQueueDelegate() {
+    isPaymentQueueDelegateRegistered = false;
+  }
+
+  @override
+  void startObservingPaymentQueue() {
+    queueIsActive = true;
+  }
+
+  @override
+  void stopObservingPaymentQueue() {
+    queueIsActive = false;
+  }
+
+  @override
+  String retrieveReceiptData() {
+    if (getReceiptFailTest) {
+      throw Exception('some arbitrary error');
+    }
+    return 'receipt data';
+  }
+
+  @override
+  Future<void> refreshReceipt({Map<String?, dynamic>? receiptProperties}) {
+    refreshReceiptCount++;
+    refreshReceiptParam =
+        Map.castFrom<dynamic, dynamic, String, dynamic>(receiptProperties!);
+    return Future<void>.sync(() {});
+  }
+
+  @override
+  void showPriceConsentIfNeeded() {
+    showPriceConsent = true;
+  }
 }
 
 class TestPaymentQueueDelegate extends SKPaymentQueueDelegateWrapper {}
diff --git a/packages/in_app_purchase/in_app_purchase_storekit/test/store_kit_wrappers/sk_payment_queue_delegate_api_test.dart b/packages/in_app_purchase/in_app_purchase_storekit/test/store_kit_wrappers/sk_payment_queue_delegate_api_test.dart
index 6c23da9cb4..03c9fda381 100644
--- a/packages/in_app_purchase/in_app_purchase_storekit/test/store_kit_wrappers/sk_payment_queue_delegate_api_test.dart
+++ b/packages/in_app_purchase/in_app_purchase_storekit/test/store_kit_wrappers/sk_payment_queue_delegate_api_test.dart
@@ -4,18 +4,18 @@
 
 import 'package:flutter/services.dart';
 import 'package:flutter_test/flutter_test.dart';
-import 'package:in_app_purchase_storekit/src/channel.dart';
 import 'package:in_app_purchase_storekit/store_kit_wrappers.dart';
 
+import '../fakes/fake_storekit_platform.dart';
+import '../test_api.g.dart';
+
 void main() {
   TestWidgetsFlutterBinding.ensureInitialized();
 
   final FakeStoreKitPlatform fakeStoreKitPlatform = FakeStoreKitPlatform();
 
   setUpAll(() {
-    TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
-        .setMockMethodCallHandler(
-            SystemChannels.platform, fakeStoreKitPlatform.onMethodCall);
+    TestInAppPurchaseApi.setup(fakeStoreKitPlatform);
   });
 
   test(
@@ -146,25 +146,3 @@ class TestPaymentQueueDelegate extends SKPaymentQueueDelegateWrapper {
     return false;
   }
 }
-
-class FakeStoreKitPlatform {
-  FakeStoreKitPlatform() {
-    TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger
-        .setMockMethodCallHandler(channel, onMethodCall);
-  }
-
-  // indicate if the payment queue delegate is registered
-  bool isPaymentQueueDelegateRegistered = false;
-
-  Future<dynamic> onMethodCall(MethodCall call) {
-    switch (call.method) {
-      case '-[SKPaymentQueue registerDelegate]':
-        isPaymentQueueDelegateRegistered = true;
-        return Future<void>.sync(() {});
-      case '-[SKPaymentQueue removeDelegate]':
-        isPaymentQueueDelegateRegistered = false;
-        return Future<void>.sync(() {});
-    }
-    return Future<dynamic>.error('method not mocked');
-  }
-}
diff --git a/packages/in_app_purchase/in_app_purchase_storekit/test/test_api.g.dart b/packages/in_app_purchase/in_app_purchase_storekit/test/test_api.g.dart
index 80debcebb7..65cd6e0bcc 100644
--- a/packages/in_app_purchase/in_app_purchase_storekit/test/test_api.g.dart
+++ b/packages/in_app_purchase/in_app_purchase_storekit/test/test_api.g.dart
@@ -1,3 +1,6 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
 // Autogenerated from Pigeon (v16.0.4), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, unnecessary_import, no_leading_underscores_for_local_identifiers
@@ -102,6 +105,20 @@ abstract class TestInAppPurchaseApi {
 
   void presentCodeRedemptionSheet();
 
+  String? retrieveReceiptData();
+
+  Future<void> refreshReceipt({Map<String?, Object?>? receiptProperties});
+
+  void startObservingPaymentQueue();
+
+  void stopObservingPaymentQueue();
+
+  void registerPaymentQueueDelegate();
+
+  void removePaymentQueueDelegate();
+
+  void showPriceConsentIfNeeded();
+
   static void setup(TestInAppPurchaseApi? api,
       {BinaryMessenger? binaryMessenger}) {
     {
@@ -331,5 +348,185 @@ abstract class TestInAppPurchaseApi {
         });
       }
     }
+    {
+      final BasicMessageChannel<Object?> __pigeon_channel = BasicMessageChannel<
+              Object?>(
+          'dev.flutter.pigeon.in_app_purchase_storekit.InAppPurchaseAPI.retrieveReceiptData',
+          pigeonChannelCodec,
+          binaryMessenger: binaryMessenger);
+      if (api == null) {
+        _testBinaryMessengerBinding!.defaultBinaryMessenger
+            .setMockDecodedMessageHandler<Object?>(__pigeon_channel, null);
+      } else {
+        _testBinaryMessengerBinding!.defaultBinaryMessenger
+            .setMockDecodedMessageHandler<Object?>(__pigeon_channel,
+                (Object? message) async {
+          try {
+            final String? output = api.retrieveReceiptData();
+            return <Object?>[output];
+          } on PlatformException catch (e) {
+            return wrapResponse(error: e);
+          } catch (e) {
+            return wrapResponse(
+                error: PlatformException(code: 'error', message: e.toString()));
+          }
+        });
+      }
+    }
+    {
+      final BasicMessageChannel<Object?> __pigeon_channel = BasicMessageChannel<
+              Object?>(
+          'dev.flutter.pigeon.in_app_purchase_storekit.InAppPurchaseAPI.refreshReceipt',
+          pigeonChannelCodec,
+          binaryMessenger: binaryMessenger);
+      if (api == null) {
+        _testBinaryMessengerBinding!.defaultBinaryMessenger
+            .setMockDecodedMessageHandler<Object?>(__pigeon_channel, null);
+      } else {
+        _testBinaryMessengerBinding!.defaultBinaryMessenger
+            .setMockDecodedMessageHandler<Object?>(__pigeon_channel,
+                (Object? message) async {
+          assert(message != null,
+              'Argument for dev.flutter.pigeon.in_app_purchase_storekit.InAppPurchaseAPI.refreshReceipt was null.');
+          final List<Object?> args = (message as List<Object?>?)!;
+          final Map<String?, Object?>? arg_receiptProperties =
+              (args[0] as Map<Object?, Object?>?)?.cast<String?, Object?>();
+          try {
+            await api.refreshReceipt(receiptProperties: arg_receiptProperties);
+            return wrapResponse(empty: true);
+          } on PlatformException catch (e) {
+            return wrapResponse(error: e);
+          } catch (e) {
+            return wrapResponse(
+                error: PlatformException(code: 'error', message: e.toString()));
+          }
+        });
+      }
+    }
+    {
+      final BasicMessageChannel<Object?> __pigeon_channel = BasicMessageChannel<
+              Object?>(
+          'dev.flutter.pigeon.in_app_purchase_storekit.InAppPurchaseAPI.startObservingPaymentQueue',
+          pigeonChannelCodec,
+          binaryMessenger: binaryMessenger);
+      if (api == null) {
+        _testBinaryMessengerBinding!.defaultBinaryMessenger
+            .setMockDecodedMessageHandler<Object?>(__pigeon_channel, null);
+      } else {
+        _testBinaryMessengerBinding!.defaultBinaryMessenger
+            .setMockDecodedMessageHandler<Object?>(__pigeon_channel,
+                (Object? message) async {
+          try {
+            api.startObservingPaymentQueue();
+            return wrapResponse(empty: true);
+          } on PlatformException catch (e) {
+            return wrapResponse(error: e);
+          } catch (e) {
+            return wrapResponse(
+                error: PlatformException(code: 'error', message: e.toString()));
+          }
+        });
+      }
+    }
+    {
+      final BasicMessageChannel<Object?> __pigeon_channel = BasicMessageChannel<
+              Object?>(
+          'dev.flutter.pigeon.in_app_purchase_storekit.InAppPurchaseAPI.stopObservingPaymentQueue',
+          pigeonChannelCodec,
+          binaryMessenger: binaryMessenger);
+      if (api == null) {
+        _testBinaryMessengerBinding!.defaultBinaryMessenger
+            .setMockDecodedMessageHandler<Object?>(__pigeon_channel, null);
+      } else {
+        _testBinaryMessengerBinding!.defaultBinaryMessenger
+            .setMockDecodedMessageHandler<Object?>(__pigeon_channel,
+                (Object? message) async {
+          try {
+            api.stopObservingPaymentQueue();
+            return wrapResponse(empty: true);
+          } on PlatformException catch (e) {
+            return wrapResponse(error: e);
+          } catch (e) {
+            return wrapResponse(
+                error: PlatformException(code: 'error', message: e.toString()));
+          }
+        });
+      }
+    }
+    {
+      final BasicMessageChannel<Object?> __pigeon_channel = BasicMessageChannel<
+              Object?>(
+          'dev.flutter.pigeon.in_app_purchase_storekit.InAppPurchaseAPI.registerPaymentQueueDelegate',
+          pigeonChannelCodec,
+          binaryMessenger: binaryMessenger);
+      if (api == null) {
+        _testBinaryMessengerBinding!.defaultBinaryMessenger
+            .setMockDecodedMessageHandler<Object?>(__pigeon_channel, null);
+      } else {
+        _testBinaryMessengerBinding!.defaultBinaryMessenger
+            .setMockDecodedMessageHandler<Object?>(__pigeon_channel,
+                (Object? message) async {
+          try {
+            api.registerPaymentQueueDelegate();
+            return wrapResponse(empty: true);
+          } on PlatformException catch (e) {
+            return wrapResponse(error: e);
+          } catch (e) {
+            return wrapResponse(
+                error: PlatformException(code: 'error', message: e.toString()));
+          }
+        });
+      }
+    }
+    {
+      final BasicMessageChannel<Object?> __pigeon_channel = BasicMessageChannel<
+              Object?>(
+          'dev.flutter.pigeon.in_app_purchase_storekit.InAppPurchaseAPI.removePaymentQueueDelegate',
+          pigeonChannelCodec,
+          binaryMessenger: binaryMessenger);
+      if (api == null) {
+        _testBinaryMessengerBinding!.defaultBinaryMessenger
+            .setMockDecodedMessageHandler<Object?>(__pigeon_channel, null);
+      } else {
+        _testBinaryMessengerBinding!.defaultBinaryMessenger
+            .setMockDecodedMessageHandler<Object?>(__pigeon_channel,
+                (Object? message) async {
+          try {
+            api.removePaymentQueueDelegate();
+            return wrapResponse(empty: true);
+          } on PlatformException catch (e) {
+            return wrapResponse(error: e);
+          } catch (e) {
+            return wrapResponse(
+                error: PlatformException(code: 'error', message: e.toString()));
+          }
+        });
+      }
+    }
+    {
+      final BasicMessageChannel<Object?> __pigeon_channel = BasicMessageChannel<
+              Object?>(
+          'dev.flutter.pigeon.in_app_purchase_storekit.InAppPurchaseAPI.showPriceConsentIfNeeded',
+          pigeonChannelCodec,
+          binaryMessenger: binaryMessenger);
+      if (api == null) {
+        _testBinaryMessengerBinding!.defaultBinaryMessenger
+            .setMockDecodedMessageHandler<Object?>(__pigeon_channel, null);
+      } else {
+        _testBinaryMessengerBinding!.defaultBinaryMessenger
+            .setMockDecodedMessageHandler<Object?>(__pigeon_channel,
+                (Object? message) async {
+          try {
+            api.showPriceConsentIfNeeded();
+            return wrapResponse(empty: true);
+          } on PlatformException catch (e) {
+            return wrapResponse(error: e);
+          } catch (e) {
+            return wrapResponse(
+                error: PlatformException(code: 'error', message: e.toString()));
+          }
+        });
+      }
+    }
   }
 }