[pigeon] [swift] Fix PigeonError sendability conformance in Swift 6 (#8302)

Ensure `PigeonError` conforms to `Sendable` for Swift 6.0 compatibility by updating the `details` property type from `Any?` to `Sendable?`.  

Fixes flutter/flutter#160313

Author: bc-lee

packages/pigeon/CHANGELOG.md

@@ -1,3 +1,8 @@
+## 23.0.0
+
+* **Breaking Change** [swift] Fixes a compile error about PigeonError's sendability conformance in Swift 6.
+  * PigeonError's init now requires the "details" argument to be Sendable.
+
 ## 22.7.4
 
 * [dart] Fixes bug with multi-instance event channel support.

packages/pigeon/example/app/ios/Runner/Messages.g.swift

@@ -18,9 +18,9 @@ import Foundation
 final class PigeonError: Error {
   let code: String
   let message: String?
-  let details: Any?
+  let details: Sendable?
 
-  init(code: String, message: String?, details: Any?) {
+  init(code: String, message: String?, details: Sendable?) {
     self.code = code
     self.message = message
     self.details = details

packages/pigeon/lib/generator_tools.dart

@@ -14,7 +14,7 @@ import 'ast.dart';
 /// The current version of pigeon.
 ///
 /// This must match the version in pubspec.yaml.
-const String pigeonVersion = '22.7.4';
+const String pigeonVersion = '23.0.0';
 
 /// Read all the content from [stdin] to a String.
 String readStdin() {

packages/pigeon/lib/swift_generator.dart

@@ -2463,10 +2463,11 @@ private func nilOrValue<T>(_ value: Any?) -> T? {
         () {
       indent.writeln('let code: String');
       indent.writeln('let message: String?');
-      indent.writeln('let details: Any?');
+      indent.writeln('let details: Sendable?');
       indent.newln();
       indent.writeScoped(
-          'init(code: String, message: String?, details: Any?) {', '}', () {
+          'init(code: String, message: String?, details: Sendable?) {', '}',
+          () {
         indent.writeln('self.code = code');
         indent.writeln('self.message = message');
         indent.writeln('self.details = details');

packages/pigeon/platform_tests/test_plugin/ios/Classes/CoreTests.gen.swift

@@ -19,9 +19,9 @@ import Foundation
 final class PigeonError: Error {
   let code: String
   let message: String?
-  let details: Any?
+  let details: Sendable?
 
-  init(code: String, message: String?, details: Any?) {
+  init(code: String, message: String?, details: Sendable?) {
     self.code = code
     self.message = message
     self.details = details

packages/pigeon/platform_tests/test_plugin/ios/Classes/EventChannelTests.gen.swift

@@ -19,9 +19,9 @@ import Foundation
 final class EventChannelTestsError: Error {
   let code: String
   let message: String?
-  let details: Any?
+  let details: Sendable?
 
-  init(code: String, message: String?, details: Any?) {
+  init(code: String, message: String?, details: Sendable?) {
     self.code = code
     self.message = message
     self.details = details

packages/pigeon/platform_tests/test_plugin/ios/Classes/ProxyApiTests.gen.swift

@@ -19,9 +19,9 @@ import Foundation
 final class ProxyApiTestsError: Error {
   let code: String
   let message: String?
-  let details: Any?
+  let details: Sendable?
 
-  init(code: String, message: String?, details: Any?) {
+  init(code: String, message: String?, details: Sendable?) {
     self.code = code
     self.message = message
     self.details = details

packages/pigeon/platform_tests/test_plugin/macos/Classes/CoreTests.gen.swift

@@ -19,9 +19,9 @@ import Foundation
 final class PigeonError: Error {
   let code: String
   let message: String?
-  let details: Any?
+  let details: Sendable?
 
-  init(code: String, message: String?, details: Any?) {
+  init(code: String, message: String?, details: Sendable?) {
     self.code = code
     self.message = message
     self.details = details

packages/pigeon/platform_tests/test_plugin/macos/Classes/EventChannelTests.gen.swift

@@ -19,9 +19,9 @@ import Foundation
 final class EventChannelTestsError: Error {
   let code: String
   let message: String?
-  let details: Any?
+  let details: Sendable?
 
-  init(code: String, message: String?, details: Any?) {
+  init(code: String, message: String?, details: Sendable?) {
     self.code = code
     self.message = message
     self.details = details

packages/pigeon/platform_tests/test_plugin/macos/Classes/ProxyApiTests.gen.swift

@@ -19,9 +19,9 @@ import Foundation
 final class ProxyApiTestsError: Error {
   let code: String
   let message: String?
-  let details: Any?
+  let details: Sendable?
 
-  init(code: String, message: String?, details: Any?) {
+  init(code: String, message: String?, details: Sendable?) {
     self.code = code
     self.message = message
     self.details = details

packages/pigeon/pubspec.yaml

@@ -2,7 +2,7 @@ name: pigeon
 description: Code generator tool to make communication between Flutter and the host platform type-safe and easier.
 repository: https://github.com/flutter/packages/tree/main/packages/pigeon
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+pigeon%22
-version: 22.7.4 # This must match the version in lib/generator_tools.dart
+version: 23.0.0 # This must match the version in lib/generator_tools.dart
 
 environment:
   sdk: ^3.4.0

packages/pigeon/test/swift_generator_test.dart

@@ -258,6 +258,27 @@ void main() {
     expect(code, contains('var aFloat64List: FlutterStandardTypedData? = nil'));
   });
 
+  test('gen pigeon error type', () {
+    final Root root = Root(apis: <Api>[], classes: <Class>[], enums: <Enum>[]);
+    final StringBuffer sink = StringBuffer();
+    const SwiftOptions swiftOptions = SwiftOptions();
+    const SwiftGenerator generator = SwiftGenerator();
+
+    generator.generate(
+      swiftOptions,
+      root,
+      sink,
+      dartPackageName: DEFAULT_PACKAGE_NAME,
+    );
+    final String code = sink.toString();
+    expect(code, contains('class PigeonError: Error'));
+    expect(code, contains('let code: String'));
+    expect(code, contains('let message: String?'));
+    expect(code, contains('let details: Sendable?'));
+    expect(code,
+        contains('init(code: String, message: String?, details: Sendable?)'));
+  });
+
   test('gen one flutter api', () {
     final Root root = Root(apis: <Api>[
       AstFlutterApi(name: 'Api', methods: <Method>[