diff --git a/packages/pigeon/pigeons/core_tests.dart b/packages/pigeon/pigeons/core_tests.dart
index 3adf890..0aa5cba 100644
--- a/packages/pigeon/pigeons/core_tests.dart
+++ b/packages/pigeon/pigeons/core_tests.dart
@@ -56,6 +56,18 @@
   @ObjCSelector('createNestedObjectWithString:')
   AllTypesWrapper createNestedString(String string);
 
+  /// Returns passed in arguments of multiple types.
+  @ObjCSelector('sendMultipleTypesABool:anInt:aString:')
+  AllTypes sendMultipleTypes(bool aBool, int anInt, String aString);
+
+  /// Returns passed in int.
+  @ObjCSelector('echoInt:')
+  int echoInt(int anInt);
+
+  /// Returns the passed in boolean asynchronously.
+  @ObjCSelector('echoBool:')
+  bool echoBool(bool aBool);
+
   // ========== Asyncronous method tests ==========
 
   /// A no-op function taking no arguments and returning no value, to sanity
diff --git a/packages/pigeon/platform_tests/alternate_language_test_plugin/android/src/main/java/com/example/alternate_language_test_plugin/AlternateLanguageTestPlugin.java b/packages/pigeon/platform_tests/alternate_language_test_plugin/android/src/main/java/com/example/alternate_language_test_plugin/AlternateLanguageTestPlugin.java
index a4057b7..bfc0e56 100644
--- a/packages/pigeon/platform_tests/alternate_language_test_plugin/android/src/main/java/com/example/alternate_language_test_plugin/AlternateLanguageTestPlugin.java
+++ b/packages/pigeon/platform_tests/alternate_language_test_plugin/android/src/main/java/com/example/alternate_language_test_plugin/AlternateLanguageTestPlugin.java
@@ -53,6 +53,24 @@
   }
 
   @Override
+  public @NonNull AllTypes sendMultipleTypes(
+      @NonNull Boolean aBool, @NonNull Long anInt, @NonNull String aString) {
+    AllTypes someThings =
+        new AllTypes.Builder().setABool(aBool).setAnInt(anInt).setAString(aString).build();
+    return someThings;
+  }
+
+  @Override
+  public Long echoInt(@NonNull Long anInt) {
+    return anInt;
+  }
+
+  @Override
+  public Boolean echoBool(@NonNull Boolean aBool) {
+    return aBool;
+  }
+
+  @Override
   public void noopAsync(Result<Void> result) {
     result.success(null);
   }
diff --git a/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/AlternateLanguageTestPlugin.m b/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/AlternateLanguageTestPlugin.m
index 4f22b7d..8f8a62e 100644
--- a/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/AlternateLanguageTestPlugin.m
+++ b/packages/pigeon/platform_tests/alternate_language_test_plugin/ios/Classes/AlternateLanguageTestPlugin.m
@@ -48,6 +48,25 @@
   return [AllTypesWrapper makeWithValues:innerObject];
 }
 
+- (nullable AllTypes *)sendMultipleTypesABool:(NSNumber *)aBool
+                                        anInt:(NSNumber *)anInt
+                                      aString:(NSString *)aString
+                                        error:(FlutterError *_Nullable *_Nonnull)error {
+  AllTypes *someTypes = [[AllTypes alloc] init];
+  someTypes.aBool = aBool;
+  someTypes.anInt = anInt;
+  someTypes.aString = aString;
+  return someTypes;
+}
+
+- (nullable NSNumber *)echoInt:(NSNumber *)anInt error:(FlutterError *_Nullable *_Nonnull)error {
+  return anInt;
+}
+
+- (nullable NSNumber *)echoBool:(NSNumber *)aBool error:(FlutterError *_Nullable *_Nonnull)error {
+  return aBool;
+}
+
 - (void)noopAsyncWithCompletion:(void (^)(FlutterError *_Nullable))completion {
   completion(nil);
 }
diff --git a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/core_tests.gen.dart b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/core_tests.gen.dart
index 701b435..7f7a4d3 100644
--- a/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/core_tests.gen.dart
+++ b/packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/core_tests.gen.dart
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v4.2.7), do not edit directly.
+// Autogenerated from Pigeon (v4.2.10), 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
 import 'dart:async';
@@ -84,6 +84,27 @@
   }
 }
 
+class AllTypesWrapper {
+  AllTypesWrapper({
+    required this.values,
+  });
+
+  AllTypes values;
+
+  Object encode() {
+    final Map<Object?, Object?> pigeonMap = <Object?, Object?>{};
+    pigeonMap['values'] = values.encode();
+    return pigeonMap;
+  }
+
+  static AllTypesWrapper decode(Object message) {
+    final Map<Object?, Object?> pigeonMap = message as Map<Object?, Object?>;
+    return AllTypesWrapper(
+      values: AllTypes.decode(pigeonMap['values']!),
+    );
+  }
+}
+
 class _HostIntegrationCoreApiCodec extends StandardMessageCodec {
   const _HostIntegrationCoreApiCodec();
   @override
@@ -91,6 +112,9 @@
     if (value is AllTypes) {
       buffer.putUint8(128);
       writeValue(buffer, value.encode());
+    } else if (value is AllTypesWrapper) {
+      buffer.putUint8(129);
+      writeValue(buffer, value.encode());
     } else {
       super.writeValue(buffer, value);
     }
@@ -102,6 +126,9 @@
       case 128:
         return AllTypes.decode(readValue(buffer)!);
 
+      case 129:
+        return AllTypesWrapper.decode(readValue(buffer)!);
+
       default:
         return super.readValueOfType(type, buffer);
     }
@@ -175,6 +202,290 @@
       return (replyMap['result'] as AllTypes?)!;
     }
   }
+
+  /// Returns an error, to test error handling.
+  Future<void> throwError() async {
+    final BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(
+        'dev.flutter.pigeon.HostIntegrationCoreApi.throwError', codec,
+        binaryMessenger: _binaryMessenger);
+    final Map<Object?, Object?>? replyMap =
+        await channel.send(null) as Map<Object?, Object?>?;
+    if (replyMap == null) {
+      throw PlatformException(
+        code: 'channel-error',
+        message: 'Unable to establish connection on channel.',
+      );
+    } else if (replyMap['error'] != null) {
+      final Map<Object?, Object?> error =
+          (replyMap['error'] as Map<Object?, Object?>?)!;
+      throw PlatformException(
+        code: (error['code'] as String?)!,
+        message: error['message'] as String?,
+        details: error['details'],
+      );
+    } else {
+      return;
+    }
+  }
+
+  /// Returns the inner `aString` value from the wrapped object, to test
+  /// sending of nested objects.
+  Future<String?> extractNestedString(AllTypesWrapper arg_wrapper) async {
+    final BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(
+        'dev.flutter.pigeon.HostIntegrationCoreApi.extractNestedString', codec,
+        binaryMessenger: _binaryMessenger);
+    final Map<Object?, Object?>? replyMap =
+        await channel.send(<Object?>[arg_wrapper]) as Map<Object?, Object?>?;
+    if (replyMap == null) {
+      throw PlatformException(
+        code: 'channel-error',
+        message: 'Unable to establish connection on channel.',
+      );
+    } else if (replyMap['error'] != null) {
+      final Map<Object?, Object?> error =
+          (replyMap['error'] as Map<Object?, Object?>?)!;
+      throw PlatformException(
+        code: (error['code'] as String?)!,
+        message: error['message'] as String?,
+        details: error['details'],
+      );
+    } else {
+      return (replyMap['result'] as String?);
+    }
+  }
+
+  /// Returns the inner `aString` value from the wrapped object, to test
+  /// sending of nested objects.
+  Future<AllTypesWrapper> createNestedString(String arg_string) async {
+    final BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(
+        'dev.flutter.pigeon.HostIntegrationCoreApi.createNestedString', codec,
+        binaryMessenger: _binaryMessenger);
+    final Map<Object?, Object?>? replyMap =
+        await channel.send(<Object?>[arg_string]) as Map<Object?, Object?>?;
+    if (replyMap == null) {
+      throw PlatformException(
+        code: 'channel-error',
+        message: 'Unable to establish connection on channel.',
+      );
+    } else if (replyMap['error'] != null) {
+      final Map<Object?, Object?> error =
+          (replyMap['error'] as Map<Object?, Object?>?)!;
+      throw PlatformException(
+        code: (error['code'] as String?)!,
+        message: error['message'] as String?,
+        details: error['details'],
+      );
+    } else if (replyMap['result'] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return (replyMap['result'] as AllTypesWrapper?)!;
+    }
+  }
+
+  /// Returns passed in arguments of multiple types.
+  Future<AllTypes> sendMultipleTypes(
+      bool arg_aBool, int arg_anInt, String arg_aString) async {
+    final BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(
+        'dev.flutter.pigeon.HostIntegrationCoreApi.sendMultipleTypes', codec,
+        binaryMessenger: _binaryMessenger);
+    final Map<Object?, Object?>? replyMap =
+        await channel.send(<Object?>[arg_aBool, arg_anInt, arg_aString])
+            as Map<Object?, Object?>?;
+    if (replyMap == null) {
+      throw PlatformException(
+        code: 'channel-error',
+        message: 'Unable to establish connection on channel.',
+      );
+    } else if (replyMap['error'] != null) {
+      final Map<Object?, Object?> error =
+          (replyMap['error'] as Map<Object?, Object?>?)!;
+      throw PlatformException(
+        code: (error['code'] as String?)!,
+        message: error['message'] as String?,
+        details: error['details'],
+      );
+    } else if (replyMap['result'] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return (replyMap['result'] as AllTypes?)!;
+    }
+  }
+
+  /// Returns passed in int.
+  Future<int> echoInt(int arg_anInt) async {
+    final BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(
+        'dev.flutter.pigeon.HostIntegrationCoreApi.echoInt', codec,
+        binaryMessenger: _binaryMessenger);
+    final Map<Object?, Object?>? replyMap =
+        await channel.send(<Object?>[arg_anInt]) as Map<Object?, Object?>?;
+    if (replyMap == null) {
+      throw PlatformException(
+        code: 'channel-error',
+        message: 'Unable to establish connection on channel.',
+      );
+    } else if (replyMap['error'] != null) {
+      final Map<Object?, Object?> error =
+          (replyMap['error'] as Map<Object?, Object?>?)!;
+      throw PlatformException(
+        code: (error['code'] as String?)!,
+        message: error['message'] as String?,
+        details: error['details'],
+      );
+    } else if (replyMap['result'] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return (replyMap['result'] as int?)!;
+    }
+  }
+
+  /// Returns the passed in boolean asynchronously.
+  Future<bool> echoBool(bool arg_aBool) async {
+    final BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(
+        'dev.flutter.pigeon.HostIntegrationCoreApi.echoBool', codec,
+        binaryMessenger: _binaryMessenger);
+    final Map<Object?, Object?>? replyMap =
+        await channel.send(<Object?>[arg_aBool]) as Map<Object?, Object?>?;
+    if (replyMap == null) {
+      throw PlatformException(
+        code: 'channel-error',
+        message: 'Unable to establish connection on channel.',
+      );
+    } else if (replyMap['error'] != null) {
+      final Map<Object?, Object?> error =
+          (replyMap['error'] as Map<Object?, Object?>?)!;
+      throw PlatformException(
+        code: (error['code'] as String?)!,
+        message: error['message'] as String?,
+        details: error['details'],
+      );
+    } else if (replyMap['result'] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return (replyMap['result'] as bool?)!;
+    }
+  }
+
+  /// A no-op function taking no arguments and returning no value, to sanity
+  /// test basic asynchronous calling.
+  Future<void> noopAsync() async {
+    final BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(
+        'dev.flutter.pigeon.HostIntegrationCoreApi.noopAsync', codec,
+        binaryMessenger: _binaryMessenger);
+    final Map<Object?, Object?>? replyMap =
+        await channel.send(null) as Map<Object?, Object?>?;
+    if (replyMap == null) {
+      throw PlatformException(
+        code: 'channel-error',
+        message: 'Unable to establish connection on channel.',
+      );
+    } else if (replyMap['error'] != null) {
+      final Map<Object?, Object?> error =
+          (replyMap['error'] as Map<Object?, Object?>?)!;
+      throw PlatformException(
+        code: (error['code'] as String?)!,
+        message: error['message'] as String?,
+        details: error['details'],
+      );
+    } else {
+      return;
+    }
+  }
+
+  /// Returns the passed string asynchronously.
+  Future<String> echoAsyncString(String arg_aString) async {
+    final BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(
+        'dev.flutter.pigeon.HostIntegrationCoreApi.echoAsyncString', codec,
+        binaryMessenger: _binaryMessenger);
+    final Map<Object?, Object?>? replyMap =
+        await channel.send(<Object?>[arg_aString]) as Map<Object?, Object?>?;
+    if (replyMap == null) {
+      throw PlatformException(
+        code: 'channel-error',
+        message: 'Unable to establish connection on channel.',
+      );
+    } else if (replyMap['error'] != null) {
+      final Map<Object?, Object?> error =
+          (replyMap['error'] as Map<Object?, Object?>?)!;
+      throw PlatformException(
+        code: (error['code'] as String?)!,
+        message: error['message'] as String?,
+        details: error['details'],
+      );
+    } else if (replyMap['result'] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return (replyMap['result'] as String?)!;
+    }
+  }
+
+  Future<void> callFlutterNoop() async {
+    final BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(
+        'dev.flutter.pigeon.HostIntegrationCoreApi.callFlutterNoop', codec,
+        binaryMessenger: _binaryMessenger);
+    final Map<Object?, Object?>? replyMap =
+        await channel.send(null) as Map<Object?, Object?>?;
+    if (replyMap == null) {
+      throw PlatformException(
+        code: 'channel-error',
+        message: 'Unable to establish connection on channel.',
+      );
+    } else if (replyMap['error'] != null) {
+      final Map<Object?, Object?> error =
+          (replyMap['error'] as Map<Object?, Object?>?)!;
+      throw PlatformException(
+        code: (error['code'] as String?)!,
+        message: error['message'] as String?,
+        details: error['details'],
+      );
+    } else {
+      return;
+    }
+  }
+
+  Future<String> callFlutterEchoString(String arg_aString) async {
+    final BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(
+        'dev.flutter.pigeon.HostIntegrationCoreApi.callFlutterEchoString',
+        codec,
+        binaryMessenger: _binaryMessenger);
+    final Map<Object?, Object?>? replyMap =
+        await channel.send(<Object?>[arg_aString]) as Map<Object?, Object?>?;
+    if (replyMap == null) {
+      throw PlatformException(
+        code: 'channel-error',
+        message: 'Unable to establish connection on channel.',
+      );
+    } else if (replyMap['error'] != null) {
+      final Map<Object?, Object?> error =
+          (replyMap['error'] as Map<Object?, Object?>?)!;
+      throw PlatformException(
+        code: (error['code'] as String?)!,
+        message: error['message'] as String?,
+        details: error['details'],
+      );
+    } else if (replyMap['result'] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return (replyMap['result'] as String?)!;
+    }
+  }
 }
 
 class _FlutterIntegrationCoreApiCodec extends StandardMessageCodec {
@@ -212,6 +523,9 @@
 
   /// Returns the passed object, to test serialization and deserialization.
   AllTypes echoAllTypes(AllTypes everything);
+
+  /// Returns the passed string, to test serialization and deserialization.
+  String echoString(String aString);
   static void setup(FlutterIntegrationCoreApi? api,
       {BinaryMessenger? binaryMessenger}) {
     {
@@ -247,6 +561,25 @@
         });
       }
     }
+    {
+      final BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(
+          'dev.flutter.pigeon.FlutterIntegrationCoreApi.echoString', codec,
+          binaryMessenger: binaryMessenger);
+      if (api == null) {
+        channel.setMessageHandler(null);
+      } else {
+        channel.setMessageHandler((Object? message) async {
+          assert(message != null,
+              'Argument for dev.flutter.pigeon.FlutterIntegrationCoreApi.echoString was null.');
+          final List<Object?> args = (message as List<Object?>?)!;
+          final String? arg_aString = (args[0] as String?);
+          assert(arg_aString != null,
+              'Argument for dev.flutter.pigeon.FlutterIntegrationCoreApi.echoString was null, expected non-null String.');
+          final String output = api.echoString(arg_aString!);
+          return output;
+        });
+      }
+    }
   }
 }
 
diff --git a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/integration_tests.dart b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/integration_tests.dart
index 08a9930..fcd2e61 100644
--- a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/integration_tests.dart
+++ b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/integration_tests.dart
@@ -27,7 +27,7 @@
   /// The iOS Objective-C generator.
   objc,
 
-  /// The iOS or macOS Objective-C generator.
+  /// The iOS or macOS Swift generator.
   swift,
 }
 
@@ -123,6 +123,40 @@
           await api.createNestedString(sentString);
       expect(receivedObject.values.aString, sentString);
     });
+
+    testWidgets(
+        'Arguments of multiple types serialize and deserialize correctly',
+        (WidgetTester _) async {
+      final HostIntegrationCoreApi api = HostIntegrationCoreApi();
+      const String aString = 'this is aString';
+      const bool aBool = false;
+      const int anInt = 42;
+
+      final AllTypes echoObject =
+          await api.sendMultipleTypes(aBool, anInt, aString);
+      expect(echoObject.anInt, anInt);
+      expect(echoObject.aBool, aBool);
+      expect(echoObject.aString, aString);
+    });
+
+    testWidgets('Ints serialize and deserialize correctly',
+        (WidgetTester _) async {
+      final HostIntegrationCoreApi api = HostIntegrationCoreApi();
+
+      const int inInt = -13;
+      final int anInt = await api.echoInt(inInt);
+      expect(anInt, inInt);
+    });
+
+    testWidgets('booleans serialize and deserialize correctly',
+        (WidgetTester _) async {
+      final HostIntegrationCoreApi api = HostIntegrationCoreApi();
+
+      for (final bool sentBool in <bool>[true, false]) {
+        final bool receivedBool = await api.echoBool(sentBool);
+        expect(receivedBool, sentBool);
+      }
+    });
   });
 
   group('Host async API tests', () {
diff --git a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/core_tests.gen.dart b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/core_tests.gen.dart
index 1b027d8..7f7a4d3 100644
--- a/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/core_tests.gen.dart
+++ b/packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/core_tests.gen.dart
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v4.2.9), do not edit directly.
+// Autogenerated from Pigeon (v4.2.10), 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
 import 'dart:async';
@@ -285,6 +285,98 @@
     }
   }
 
+  /// Returns passed in arguments of multiple types.
+  Future<AllTypes> sendMultipleTypes(
+      bool arg_aBool, int arg_anInt, String arg_aString) async {
+    final BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(
+        'dev.flutter.pigeon.HostIntegrationCoreApi.sendMultipleTypes', codec,
+        binaryMessenger: _binaryMessenger);
+    final Map<Object?, Object?>? replyMap =
+        await channel.send(<Object?>[arg_aBool, arg_anInt, arg_aString])
+            as Map<Object?, Object?>?;
+    if (replyMap == null) {
+      throw PlatformException(
+        code: 'channel-error',
+        message: 'Unable to establish connection on channel.',
+      );
+    } else if (replyMap['error'] != null) {
+      final Map<Object?, Object?> error =
+          (replyMap['error'] as Map<Object?, Object?>?)!;
+      throw PlatformException(
+        code: (error['code'] as String?)!,
+        message: error['message'] as String?,
+        details: error['details'],
+      );
+    } else if (replyMap['result'] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return (replyMap['result'] as AllTypes?)!;
+    }
+  }
+
+  /// Returns passed in int.
+  Future<int> echoInt(int arg_anInt) async {
+    final BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(
+        'dev.flutter.pigeon.HostIntegrationCoreApi.echoInt', codec,
+        binaryMessenger: _binaryMessenger);
+    final Map<Object?, Object?>? replyMap =
+        await channel.send(<Object?>[arg_anInt]) as Map<Object?, Object?>?;
+    if (replyMap == null) {
+      throw PlatformException(
+        code: 'channel-error',
+        message: 'Unable to establish connection on channel.',
+      );
+    } else if (replyMap['error'] != null) {
+      final Map<Object?, Object?> error =
+          (replyMap['error'] as Map<Object?, Object?>?)!;
+      throw PlatformException(
+        code: (error['code'] as String?)!,
+        message: error['message'] as String?,
+        details: error['details'],
+      );
+    } else if (replyMap['result'] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return (replyMap['result'] as int?)!;
+    }
+  }
+
+  /// Returns the passed in boolean asynchronously.
+  Future<bool> echoBool(bool arg_aBool) async {
+    final BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(
+        'dev.flutter.pigeon.HostIntegrationCoreApi.echoBool', codec,
+        binaryMessenger: _binaryMessenger);
+    final Map<Object?, Object?>? replyMap =
+        await channel.send(<Object?>[arg_aBool]) as Map<Object?, Object?>?;
+    if (replyMap == null) {
+      throw PlatformException(
+        code: 'channel-error',
+        message: 'Unable to establish connection on channel.',
+      );
+    } else if (replyMap['error'] != null) {
+      final Map<Object?, Object?> error =
+          (replyMap['error'] as Map<Object?, Object?>?)!;
+      throw PlatformException(
+        code: (error['code'] as String?)!,
+        message: error['message'] as String?,
+        details: error['details'],
+      );
+    } else if (replyMap['result'] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return (replyMap['result'] as bool?)!;
+    }
+  }
+
   /// A no-op function taking no arguments and returning no value, to sanity
   /// test basic asynchronous calling.
   Future<void> noopAsync() async {
diff --git a/packages/pigeon/platform_tests/test_plugin/android/src/main/kotlin/com/example/test_plugin/TestPlugin.kt b/packages/pigeon/platform_tests/test_plugin/android/src/main/kotlin/com/example/test_plugin/TestPlugin.kt
index 9a2961b..73d9a71 100644
--- a/packages/pigeon/platform_tests/test_plugin/android/src/main/kotlin/com/example/test_plugin/TestPlugin.kt
+++ b/packages/pigeon/platform_tests/test_plugin/android/src/main/kotlin/com/example/test_plugin/TestPlugin.kt
@@ -48,6 +48,19 @@
     return AllTypesWrapper(AllTypes(aString = string))
   }
 
+  override fun sendMultipleTypes(aBool: Boolean, anInt: Long, aString: String): AllTypes {
+    var someThings = AllTypes(aBool = aBool, anInt = anInt, aString = aString)
+    return someThings
+  }
+
+  override fun echoInt(anInt: Long): Long {
+    return anInt
+  }
+
+  override fun echoBool(aBool: Boolean): Boolean {
+    return aBool
+  }
+
   override fun noopAsync(callback: () -> Unit) {
     callback()
   }
diff --git a/packages/pigeon/platform_tests/test_plugin/ios/Classes/TestPlugin.swift b/packages/pigeon/platform_tests/test_plugin/ios/Classes/TestPlugin.swift
index 73fc349..441d980 100644
--- a/packages/pigeon/platform_tests/test_plugin/ios/Classes/TestPlugin.swift
+++ b/packages/pigeon/platform_tests/test_plugin/ios/Classes/TestPlugin.swift
@@ -43,6 +43,19 @@
     return AllTypesWrapper(values: AllTypes(aString: string))
   }
 
+  func sendMultipleTypes(aBool: Bool, anInt: Int32, aString: String) -> AllTypes {
+    let someThings = AllTypes(aBool: aBool, anInt: anInt, aString: aString)
+    return someThings
+  }
+
+  func echoInt(anInt: Int32) -> Int32 {
+    return anInt
+  }
+
+  func echoBool(aBool: Bool) -> Bool {
+    return aBool
+  }
+
   func noopAsync(completion: @escaping () -> Void) {
     completion()
   }
diff --git a/packages/pigeon/platform_tests/test_plugin/macos/Classes/TestPlugin.swift b/packages/pigeon/platform_tests/test_plugin/macos/Classes/TestPlugin.swift
index a9da20c..2b22866 100644
--- a/packages/pigeon/platform_tests/test_plugin/macos/Classes/TestPlugin.swift
+++ b/packages/pigeon/platform_tests/test_plugin/macos/Classes/TestPlugin.swift
@@ -43,6 +43,19 @@
     return AllTypesWrapper(values: AllTypes(aString: string))
   }
 
+  func sendMultipleTypes(aBool: Bool, anInt: Int32, aString: String) -> AllTypes {
+    let someThings = AllTypes(aBool: aBool, anInt: anInt, aString: aString)
+    return someThings
+  }
+
+  func echoInt(anInt: Int32) -> Int32 {
+    return anInt
+  }
+
+  func echoBool(aBool: Bool) -> Bool {
+    return aBool
+  }
+
   func noopAsync(completion: @escaping () -> Void) {
     completion()
   }
diff --git a/packages/pigeon/platform_tests/test_plugin/windows/test_plugin.cpp b/packages/pigeon/platform_tests/test_plugin/windows/test_plugin.cpp
index 43dbd0b..e6a4221 100644
--- a/packages/pigeon/platform_tests/test_plugin/windows/test_plugin.cpp
+++ b/packages/pigeon/platform_tests/test_plugin/windows/test_plugin.cpp
@@ -65,6 +65,19 @@
   return wrapper;
 }
 
+ErrorOr<AllTypes> TestPlugin::SendMultipleTypes(bool a_bool, int64_t an_int,
+                                                const std::string& a_string) {
+  AllTypes someTypes;
+  someTypes.set_a_bool(a_bool);
+  someTypes.set_an_int(an_int);
+  someTypes.set_a_string(a_string);
+  return someTypes;
+};
+
+ErrorOr<int64_t> TestPlugin::EchoInt(int64_t an_int) { return an_int; }
+
+ErrorOr<bool> TestPlugin::EchoBool(bool a_bool) { return a_bool; }
+
 void TestPlugin::NoopAsync(
     std::function<void(std::optional<FlutterError> reply)> result) {
   result(std::nullopt);
diff --git a/packages/pigeon/platform_tests/test_plugin/windows/test_plugin.h b/packages/pigeon/platform_tests/test_plugin/windows/test_plugin.h
index 0b162d0..4c4bfac 100644
--- a/packages/pigeon/platform_tests/test_plugin/windows/test_plugin.h
+++ b/packages/pigeon/platform_tests/test_plugin/windows/test_plugin.h
@@ -41,6 +41,11 @@
       const core_tests_pigeontest::AllTypesWrapper& wrapper) override;
   core_tests_pigeontest::ErrorOr<core_tests_pigeontest::AllTypesWrapper>
   CreateNestedString(const std::string& string) override;
+  core_tests_pigeontest::ErrorOr<core_tests_pigeontest::AllTypes>
+  SendMultipleTypes(bool a_bool, int64_t an_int,
+                    const std::string& a_string) override;
+  core_tests_pigeontest::ErrorOr<int64_t> EchoInt(int64_t an_int) override;
+  core_tests_pigeontest::ErrorOr<bool> EchoBool(bool a_bool) override;
   void NoopAsync(std::function<
                  void(std::optional<core_tests_pigeontest::FlutterError> reply)>
                      result) override;