Allow iOS and macOS plugins to share darwin directory

dev/devicelab/bin/tasks/plugin_test_ios.dart

@@ -13,6 +13,9 @@ Future<void> main() async {
     // Test that Dart-only plugins are supported.
     PluginTest('ios', <String>['--platforms=ios'], dartOnlyPlugin: true).call,
     PluginTest('macos', <String>['--platforms=macos'], dartOnlyPlugin: true).call,
+    // Test that shared darwin directories are supported.
+    PluginTest('ios', <String>['--platforms=ios,macos'], sharedDarwinSource: true).call,
+    PluginTest('macos', <String>['--platforms=ios,macos'], sharedDarwinSource: true).call,
     // Test that FFI plugins are supported.
     PluginTest('ios', <String>['--platforms=ios'], template: 'plugin_ffi').call,
     PluginTest('macos', <String>['--platforms=macos'], template: 'plugin_ffi').call,

dev/devicelab/lib/tasks/plugin_tests.dart

@@ -33,6 +33,7 @@ class PluginTest {
     this.pluginCreateEnvironment,
     this.appCreateEnvironment,
     this.dartOnlyPlugin = false,
+    this.sharedDarwinSource = false,
     this.template = 'plugin',
   });
 
@@ -41,6 +42,7 @@ class PluginTest {
   final Map<String, String>? pluginCreateEnvironment;
   final Map<String, String>? appCreateEnvironment;
   final bool dartOnlyPlugin;
+  final bool sharedDarwinSource;
   final String template;
 
   Future<TaskResult> call() async {
@@ -58,6 +60,9 @@ class PluginTest {
       if (dartOnlyPlugin) {
         await plugin.convertDefaultPluginToDartPlugin();
       }
+      if (sharedDarwinSource) {
+        await plugin.convertDefaultPluginToSharedDarwinPlugin();
+      }
       section('Test plugin');
       if (runFlutterTest) {
         await plugin.runFlutterTest();
@@ -159,6 +164,79 @@ class $dartPluginClass {
     }
   }
 
+  /// Converts an iOS/macOS plugin created from the standard template to a shared
+  /// darwin directory plugin.
+  Future<void> convertDefaultPluginToSharedDarwinPlugin() async {
+    // Convert the metadata.
+    final File pubspec = pubspecFile;
+    String pubspecContent = await pubspec.readAsString();
+    const String originalIOSKey = '\n      ios:\n';
+    const String originalMacOSKey = '\n      macos:\n';
+    if (!pubspecContent.contains(originalIOSKey) || !pubspecContent.contains(originalMacOSKey)) {
+      print(pubspecContent);
+      throw TaskResult.failure('Missing expected darwin platform plugin keys');
+    }
+    pubspecContent = pubspecContent.replaceAll(
+        originalIOSKey,
+        '$originalIOSKey        sharedDarwinSource: true\n'
+    );
+    pubspecContent = pubspecContent.replaceAll(
+        originalMacOSKey,
+        '$originalMacOSKey        sharedDarwinSource: true\n'
+    );
+    await pubspec.writeAsString(pubspecContent, flush: true);
+
+    // Copy ios to darwin, and delete macos.
+    final Directory iosDir = Directory(path.join(rootPath, 'ios'));
+    final Directory darwinDir = Directory(path.join(rootPath, 'darwin'));
+    recursiveCopy(iosDir, darwinDir);
+
+    await iosDir.delete(recursive: true);
+    await Directory(path.join(rootPath, 'macos')).delete(recursive: true);
+
+    final File podspec = File(path.join(darwinDir.path, '$name.podspec'));
+    String podspecContent = await podspec.readAsString();
+    if (!podspecContent.contains('s.platform =')) {
+      print(podspecContent);
+      throw TaskResult.failure('Missing expected podspec platform');
+    }
+
+    // Remove "s.platform = :ios" to work on all platforms, including macOS.
+    podspecContent = podspecContent.replaceFirst(RegExp(r'.*s\.platform.*'), '');
+    podspecContent = podspecContent.replaceFirst("s.dependency 'Flutter'", "s.ios.dependency 'Flutter'\ns.osx.dependency 'FlutterMacOS'");
+
+    await podspec.writeAsString(podspecContent, flush: true);
+
+    // Make PlugintestPlugin.swift compile on iOS and macOS with target conditionals.
+    final String pluginClass = '${name[0].toUpperCase()}${name.substring(1)}Plugin';
+    print('pluginClass: $pluginClass');
+    final File pluginRegister = File(path.join(darwinDir.path, 'Classes', '$pluginClass.swift'));
+    final String pluginRegisterContent = '''
+#if os(macOS)
+import FlutterMacOS
+#elseif os(iOS)
+import Flutter
+#endif
+
+public class $pluginClass: NSObject, FlutterPlugin {
+  public static func register(with registrar: FlutterPluginRegistrar) {
+#if os(macOS)
+    let channel = FlutterMethodChannel(name: "$name", binaryMessenger: registrar.messenger)
+#elseif os(iOS)
+    let channel = FlutterMethodChannel(name: "$name", binaryMessenger: registrar.messenger())
+#endif
+    let instance = $pluginClass()
+    registrar.addMethodCallDelegate(instance, channel: channel)
+  }
+
+  public func handle(_ call: FlutterMethodCall, result: @escaping FlutterResult) {
+    result("called " + call.method)
+  }
+}
+''';
+    await pluginRegister.writeAsString(pluginRegisterContent, flush: true);
+  }
+
   Future<void> runFlutterTest() async {
     await inDirectory(Directory(rootPath), () async {
       await flutter('test');

packages/flutter_tools/bin/podhelper.rb

@@ -266,14 +266,19 @@ def flutter_install_plugin_pods(application_path = nil, relative_symlink_dir, pl
     plugin_name = plugin_hash['name']
     plugin_path = plugin_hash['path']
     has_native_build = plugin_hash.fetch('native_build', true)
+
+    # iOS and macOS code can be shared in "darwin" directory, otherwise
+    # respectively in "ios" or "macos" directories.
+    shared_darwin_source = plugin_hash.fetch('shared_darwin_source', false)
+    platform_directory = shared_darwin_source ? 'darwin' : platform
     next unless plugin_name && plugin_path && has_native_build
     symlink = File.join(symlink_plugins_dir, plugin_name)
     File.symlink(plugin_path, symlink)
 
     # Keep pod path relative so it can be checked into Podfile.lock.
     relative = flutter_relative_path_from_podfile(symlink)
 
-    pod plugin_name, path: File.join(relative, platform)
+    pod plugin_name, path: File.join(relative, platform_directory)
   end
 end
 
@@ -288,7 +293,7 @@ def flutter_parse_plugins_file(file, platform)
 
   # dependencies_hash.dig('plugins', 'ios') not available until Ruby 2.3
   return [] unless dependencies_hash.has_key?('plugins')
-  return [] unless dependencies_hash['plugins'].has_key?('ios')
+  return [] unless dependencies_hash['plugins'].has_key?(platform)
   dependencies_hash['plugins'][platform] || []
 end
 

packages/flutter_tools/lib/src/flutter_plugins.dart

@@ -104,6 +104,7 @@ const String _kFlutterPluginsNameKey = 'name';
 const String _kFlutterPluginsPathKey = 'path';
 const String _kFlutterPluginsDependenciesKey = 'dependencies';
 const String _kFlutterPluginsHasNativeBuildKey = 'native_build';
+const String _kFlutterPluginsSharedDarwinSource = 'shared_darwin_source';
 
 /// Filters [plugins] to those supported by [platformKey].
 List<Map<String, Object>> _filterPluginsByPlatform(List<Plugin> plugins, String platformKey) {
@@ -119,6 +120,8 @@ List<Map<String, Object>> _filterPluginsByPlatform(List<Plugin> plugins, String
     pluginInfo.add(<String, Object>{
       _kFlutterPluginsNameKey: plugin.name,
       _kFlutterPluginsPathKey: globals.fsUtils.escapePath(plugin.path),
+      if (platformPlugin is DarwinPlugin && (platformPlugin as DarwinPlugin).sharedDarwinSource)
+        _kFlutterPluginsSharedDarwinSource: (platformPlugin as DarwinPlugin).sharedDarwinSource,
       if (platformPlugin is NativeOrDartPlugin)
         _kFlutterPluginsHasNativeBuildKey: (platformPlugin as NativeOrDartPlugin).hasMethodChannel() || (platformPlugin as NativeOrDartPlugin).hasFfi(),
       _kFlutterPluginsDependenciesKey: <String>[...plugin.dependencies.where(pluginNames.contains)],

packages/flutter_tools/lib/src/platform_plugins.dart

@@ -19,6 +19,10 @@ const String kFfiPlugin = 'ffiPlugin';
 // Constant for 'defaultPackage' key in plugin maps.
 const String kDefaultPackage = 'default_package';
 
+/// Constant for 'sharedDarwinSource' key in plugin maps.
+/// Can be set for iOS and macOS plugins.
+const String kSharedDarwinSource = 'sharedDarwinSource';
+
 /// Constant for 'supportedVariants' key in plugin maps.
 const String kSupportedVariants = 'supportedVariants';
 
@@ -52,6 +56,11 @@ abstract class NativeOrDartPlugin {
   bool hasMethodChannel();
 }
 
+abstract class DarwinPlugin {
+  /// Indicates the iOS and macOS native code is shareable the subdirectory "darwin",
+  bool get sharedDarwinSource;
+}
+
 /// Contains parameters to template an Android plugin.
 ///
 /// The [name] of the plugin is required. Additionally, either:
@@ -227,15 +236,17 @@ class AndroidPlugin extends PluginPlatform implements NativeOrDartPlugin {
 ///   - the [dartPluginClass] that will be the entry point for the plugin's
 ///     Dart code
 /// is required.
-class IOSPlugin extends PluginPlatform implements NativeOrDartPlugin {
+class IOSPlugin extends PluginPlatform implements NativeOrDartPlugin, DarwinPlugin {
   const IOSPlugin({
     required this.name,
     required this.classPrefix,
     this.pluginClass,
     this.dartPluginClass,
     bool? ffiPlugin,
     this.defaultPackage,
-  }) : ffiPlugin = ffiPlugin ?? false;
+    bool? sharedDarwinSource,
+  }) : ffiPlugin = ffiPlugin ?? false,
+       sharedDarwinSource = sharedDarwinSource ?? false;
 
   factory IOSPlugin.fromYaml(String name, YamlMap yaml) {
     assert(validate(yaml)); // TODO(zanderso): https://github.com/flutter/flutter/issues/67241
@@ -246,6 +257,7 @@ class IOSPlugin extends PluginPlatform implements NativeOrDartPlugin {
       dartPluginClass: yaml[kDartPluginClass] as String?,
       ffiPlugin: yaml[kFfiPlugin] as bool?,
       defaultPackage: yaml[kDefaultPackage] as String?,
+      sharedDarwinSource: yaml[kSharedDarwinSource] as bool?,
     );
   }
 
@@ -256,6 +268,7 @@ class IOSPlugin extends PluginPlatform implements NativeOrDartPlugin {
     return yaml[kPluginClass] is String ||
         yaml[kDartPluginClass] is String ||
         yaml[kFfiPlugin] == true ||
+        yaml[kSharedDarwinSource] == true ||
         yaml[kDefaultPackage] is String;
   }
 
@@ -271,6 +284,11 @@ class IOSPlugin extends PluginPlatform implements NativeOrDartPlugin {
   final bool ffiPlugin;
   final String? defaultPackage;
 
+  /// Indicates the iOS native code is shareable with macOS in
+  /// the subdirectory "darwin", otherwise in the subdirectory "ios".
+  @override
+  final bool sharedDarwinSource;
+
   @override
   bool hasMethodChannel() => pluginClass != null;
 
@@ -288,6 +306,7 @@ class IOSPlugin extends PluginPlatform implements NativeOrDartPlugin {
       if (pluginClass != null) 'class': pluginClass,
       if (dartPluginClass != null) kDartPluginClass : dartPluginClass,
       if (ffiPlugin) kFfiPlugin: true,
+      if (sharedDarwinSource) kSharedDarwinSource: true,
       if (defaultPackage != null) kDefaultPackage : defaultPackage,
     };
   }
@@ -298,14 +317,16 @@ class IOSPlugin extends PluginPlatform implements NativeOrDartPlugin {
 /// The [name] of the plugin is required. Either [dartPluginClass] or
 /// [pluginClass] or [ffiPlugin] are required.
 /// [pluginClass] will be the entry point to the plugin's native code.
-class MacOSPlugin extends PluginPlatform implements NativeOrDartPlugin {
+class MacOSPlugin extends PluginPlatform implements NativeOrDartPlugin, DarwinPlugin {
   const MacOSPlugin({
     required this.name,
     this.pluginClass,
     this.dartPluginClass,
     bool? ffiPlugin,
     this.defaultPackage,
-  }) : ffiPlugin = ffiPlugin ?? false;
+    bool? sharedDarwinSource,
+  }) : ffiPlugin = ffiPlugin ?? false,
+       sharedDarwinSource = sharedDarwinSource ?? false;
 
   factory MacOSPlugin.fromYaml(String name, YamlMap yaml) {
     assert(validate(yaml));
@@ -320,6 +341,7 @@ class MacOSPlugin extends PluginPlatform implements NativeOrDartPlugin {
       dartPluginClass: yaml[kDartPluginClass] as String?,
       ffiPlugin: yaml[kFfiPlugin] as bool?,
       defaultPackage: yaml[kDefaultPackage] as String?,
+      sharedDarwinSource: yaml[kSharedDarwinSource] as bool?,
     );
   }
 
@@ -330,6 +352,7 @@ class MacOSPlugin extends PluginPlatform implements NativeOrDartPlugin {
     return yaml[kPluginClass] is String ||
         yaml[kDartPluginClass] is String ||
         yaml[kFfiPlugin] == true ||
+        yaml[kSharedDarwinSource] == true ||
         yaml[kDefaultPackage] is String;
   }
 
@@ -341,6 +364,11 @@ class MacOSPlugin extends PluginPlatform implements NativeOrDartPlugin {
   final bool ffiPlugin;
   final String? defaultPackage;
 
+  /// Indicates the macOS native code is shareable with iOS in
+  /// the subdirectory "darwin", otherwise in the subdirectory "macos".
+  @override
+  final bool sharedDarwinSource;
+
   @override
   bool hasMethodChannel() => pluginClass != null;
 
@@ -357,6 +385,7 @@ class MacOSPlugin extends PluginPlatform implements NativeOrDartPlugin {
       if (pluginClass != null) 'class': pluginClass,
       if (dartPluginClass != null) kDartPluginClass: dartPluginClass,
       if (ffiPlugin) kFfiPlugin: true,
+      if (sharedDarwinSource) kSharedDarwinSource: true,
       if (defaultPackage != null) kDefaultPackage: defaultPackage,
     };
   }

packages/flutter_tools/test/general.shard/plugin_parsing_test.dart

@@ -35,6 +35,7 @@ void main() {
 
     expect(iosPlugin.pluginClass, 'SamplePlugin');
     expect(iosPlugin.classPrefix, 'FLT');
+    expect(iosPlugin.sharedDarwinSource, isFalse);
     expect(androidPlugin.pluginClass, 'SamplePlugin');
     expect(androidPlugin.package, 'com.flutter.dev');
   });
@@ -47,10 +48,12 @@ void main() {
       '  pluginClass: ASamplePlugin\n'
       ' ios:\n'
       '  pluginClass: ISamplePlugin\n'
+      '  sharedDarwinSource: true\n'
       ' linux:\n'
       '  pluginClass: LSamplePlugin\n'
       ' macos:\n'
       '  pluginClass: MSamplePlugin\n'
+      '  sharedDarwinSource: true\n'
       ' web:\n'
       '  pluginClass: WebSamplePlugin\n'
       '  fileName: web_plugin.dart\n'
@@ -76,10 +79,12 @@ void main() {
 
     expect(iosPlugin.pluginClass, 'ISamplePlugin');
     expect(iosPlugin.classPrefix, '');
+    expect(iosPlugin.sharedDarwinSource, isTrue);
     expect(androidPlugin.pluginClass, 'ASamplePlugin');
     expect(androidPlugin.package, 'com.flutter.dev');
     expect(linuxPlugin.pluginClass, 'LSamplePlugin');
     expect(macOSPlugin.pluginClass, 'MSamplePlugin');
+    expect(macOSPlugin.sharedDarwinSource, isTrue);
     expect(webPlugin.pluginClass, 'WebSamplePlugin');
     expect(webPlugin.fileName, 'web_plugin.dart');
     expect(windowsPlugin.pluginClass, 'WinSamplePlugin');
@@ -124,10 +129,12 @@ void main() {
 
     expect(iosPlugin.pluginClass, 'ISamplePlugin');
     expect(iosPlugin.classPrefix, '');
+    expect(iosPlugin.sharedDarwinSource, isFalse);
     expect(androidPlugin.pluginClass, 'ASamplePlugin');
     expect(androidPlugin.package, 'com.flutter.dev');
     expect(linuxPlugin.pluginClass, 'LSamplePlugin');
     expect(macOSPlugin.pluginClass, 'MSamplePlugin');
+    expect(macOSPlugin.sharedDarwinSource, isFalse);
     expect(webPlugin.pluginClass, 'WebSamplePlugin');
     expect(webPlugin.fileName, 'web_plugin.dart');
     expect(windowsPlugin.pluginClass, 'WinSamplePlugin');