Add `--platforms` to `flutter create -t plugin` command (#59507)

dev/devicelab/bin/tasks/build_aar_module_test.dart

@@ -41,7 +41,7 @@ Future<void> main() async {
       await inDirectory(tempDir, () async {
         await flutter(
           'create',
-          options: <String>['--org', 'io.flutter.devicelab', '--template', 'plugin', 'plugin_with_android'],
+          options: <String>['--org', 'io.flutter.devicelab', '--template', 'plugin', '--platforms=android', 'plugin_with_android'],
         );
       });
 
@@ -50,25 +50,10 @@ Future<void> main() async {
       await inDirectory(tempDir, () async {
         await flutter(
           'create',
-          options: <String>['--org', 'io.flutter.devicelab', '--template', 'plugin', 'plugin_without_android'],
+          options: <String>['--org', 'io.flutter.devicelab', '--template', 'plugin', '--platforms=ios', 'plugin_without_android'],
         );
       });
 
-      // Delete the android/ directory.
-      File(path.join(
-        tempDir.path,
-        'plugin_without_android',
-        'android'
-      )).deleteSync(recursive: true);
-
-      // Remove Android support from the plugin pubspec.yaml
-      final File pluginPubspec = File(path.join(tempDir.path, 'plugin_without_android', 'pubspec.yaml'));
-      pluginPubspec.writeAsStringSync(pluginPubspec.readAsStringSync().replaceFirst('''
-      android:
-        package: io.flutter.devicelab.plugin_without_android
-        pluginClass: PluginWithoutAndroidPlugin
-''', ''), flush: true);
-
       section('Add plugins to pubspec.yaml');
 
       final File modulePubspec = File(path.join(projectDir.path, 'pubspec.yaml'));

dev/devicelab/bin/tasks/gradle_non_android_plugin_test.dart

@@ -32,6 +32,7 @@ Future<void> main() async {
           options: <String>[
             '--org', 'io.flutter.devicelab',
             '-t', 'plugin',
+            '--platforms=ios,android',
             'ios_only',
           ],
         );

dev/devicelab/bin/tasks/plugin_dependencies_test.dart

@@ -40,6 +40,7 @@ Future<void> main() async {
             '--org',
             'io.flutter.devicelab.plugin_a',
             '--template=plugin',
+            '--platforms=android,ios',
             pluginADirectory.path,
           ],
         );
@@ -55,6 +56,7 @@ Future<void> main() async {
             '--org',
             'io.flutter.devicelab.plugin_b',
             '--template=plugin',
+            '--platforms=android,ios',
             pluginBDirectory.path,
           ],
         );
@@ -70,6 +72,7 @@ Future<void> main() async {
             '--org',
             'io.flutter.devicelab.plugin_c',
             '--template=plugin',
+            '--platforms=ios',
             pluginCDirectory.path,
           ],
         );

dev/devicelab/bin/tasks/plugin_lint_mac.dart

@@ -26,6 +26,7 @@ Future<void> main() async {
             '--org',
             'io.flutter.devicelab',
             '--template=plugin',
+            '--platforms=ios,android',
             '--ios-language=objc',
             objcPluginName,
           ],
@@ -79,6 +80,7 @@ Future<void> main() async {
             '--org',
             'io.flutter.devicelab',
             '--template=plugin',
+            '--platforms=ios,android',
             '--ios-language=swift',
             swiftPluginName,
           ],

dev/devicelab/bin/tasks/plugin_test.dart

@@ -9,14 +9,14 @@ import 'package:flutter_devicelab/framework/framework.dart';
 
 Future<void> main() async {
   await task(combine(<TaskFunction>[
-    PluginTest('apk', <String>['-a', 'java']),
-    PluginTest('apk', <String>['-a', 'kotlin']),
+    PluginTest('apk', <String>['-a', 'java', '--platforms=android']),
+    PluginTest('apk', <String>['-a', 'kotlin', '--platforms=android']),
     // These create the plugins using the new v2 plugin templates but create the
     // apps using the old v1 embedding app templates to make sure new plugins
     // are by default backward compatible.
-    PluginTest('apk', <String>['-a', 'java'], pluginCreateEnvironment:
+    PluginTest('apk', <String>['-a', 'java', '--platforms=android'], pluginCreateEnvironment:
         <String, String>{'ENABLE_ANDROID_EMBEDDING_V2': 'true'}),
-    PluginTest('apk', <String>['-a', 'kotlin'], pluginCreateEnvironment:
+    PluginTest('apk', <String>['-a', 'kotlin', '--platforms=android'], pluginCreateEnvironment:
         <String, String>{'ENABLE_ANDROID_EMBEDDING_V2': 'true'}),
   ]));
 }

dev/devicelab/bin/tasks/plugin_test_ios.dart

@@ -9,7 +9,7 @@ import 'package:flutter_devicelab/framework/framework.dart';
 
 Future<void> main() async {
   await task(combine(<TaskFunction>[
-    PluginTest('ios', <String>['-i', 'objc']),
-    PluginTest('ios', <String>['-i', 'swift']),
+    PluginTest('ios', <String>['-i', 'objc', '--platforms=ios']),
+    PluginTest('ios', <String>['-i', 'swift', '--platforms=ios']),
   ]));
 }

dev/devicelab/bin/tasks/plugin_test_win.dart

@@ -9,7 +9,7 @@ import 'package:flutter_devicelab/framework/framework.dart';
 
 Future<void> main() async {
   await task(combine(<TaskFunction>[
-    PluginTest('apk', <String>['-a', 'java']),
-    PluginTest('apk', <String>['-a', 'kotlin']),
+    PluginTest('apk', <String>['-a', 'java', '--platforms=android']),
+    PluginTest('apk', <String>['-a', 'kotlin', '--platforms=android']),
   ]));
 }

dev/devicelab/lib/framework/apk_utils.dart

@@ -351,7 +351,7 @@ class FlutterPluginProject {
 
   static Future<FlutterPluginProject> create(Directory directory, String name) async {
     await inDirectory(directory, () async {
-      await flutter('create', options: <String>['--template=plugin', name]);
+      await flutter('create', options: <String>['--template=plugin', '--platforms=ios,android', name]);
     });
     return FlutterPluginProject(directory, name);
   }

packages/flutter_tools/lib/src/flutter_manifest.dart

@@ -163,17 +163,16 @@ class FlutterManifest {
     if (isModule) {
       return _flutterDescriptor['module']['androidPackage'] as String;
     }
-    if (isPlugin) {
-      final YamlMap plugin = _flutterDescriptor['plugin'] as YamlMap;
-      if (plugin.containsKey('platforms')) {
-        final YamlMap platforms = plugin['platforms'] as YamlMap;
-
-        if (platforms.containsKey('android')) {
-          return platforms['android']['package'] as String;
-        }
-      } else {
+    if (supportedPlatforms == null) {
+      // Pre-multi-platform plugin format
+      if (isPlugin) {
+        final YamlMap plugin = _flutterDescriptor['plugin'] as YamlMap;
         return plugin['androidPackage'] as String;
       }
+      return null;
+    }
+    if (supportedPlatforms.containsKey('android')) {
+       return supportedPlatforms['android']['package'] as String;
     }
     return null;
   }
@@ -187,6 +186,20 @@ class FlutterManifest {
     return null;
   }
 
+  /// Gets the supported platforms. This only supports the new `platforms` format.
+  ///
+  /// If the plugin uses the legacy pubspec format, this method returns null.
+  Map<String, dynamic> get supportedPlatforms {
+    if (isPlugin) {
+      final YamlMap plugin = _flutterDescriptor['plugin'] as YamlMap;
+      if (plugin.containsKey('platforms')) {
+        final YamlMap platformsMap = plugin['platforms'] as YamlMap;
+        return platformsMap.value.cast<String, dynamic>();
+      }
+    }
+    return null;
+  }
+
   List<Map<String, dynamic>> get fontsDescriptor {
     return fonts.map((Font font) => font.descriptor).toList();
   }

packages/flutter_tools/lib/src/plugins.dart

@@ -174,6 +174,25 @@ class Plugin {
     );
   }
 
+  /// Create a YamlMap that represents the supported platforms.
+  ///
+  /// For example, if the `platforms` contains 'ios' and 'android', the return map looks like:
+  ///    android:
+  ///      package: io.flutter.plugins.sample
+  ///      pluginClass: SamplePlugin
+  ///    ios:
+  ///      pluginClass: SamplePlugin
+  static YamlMap createPlatformsYamlMap(List<String> platforms, String pluginClass, String androidPackage) {
+    final Map<String, dynamic> map = <String, dynamic>{};
+    for (final String platform in platforms) {
+      map[platform] = <String, String>{
+        'pluginClass': pluginClass,
+        ...platform == 'android' ? <String, String>{'package': androidPackage} : <String, String>{},
+      };
+    }
+    return YamlMap.wrap(map);
+  }
+
   static List<String> validatePluginYaml(YamlMap yaml) {
     if (yaml == null) {
       return <String>['Invalid "plugin" specification.'];

packages/flutter_tools/lib/src/project.dart

@@ -225,6 +225,9 @@ class FlutterProject {
 
   /// Generates project files necessary to make Gradle builds work on Android
   /// and CocoaPods+Xcode work on iOS, for app and module projects only.
+  // TODO(cyanglaz): The param `checkProjects` is confusing. We should give it a better name
+  // or add some documentation explaining what it does, or both.
+  // https://github.com/flutter/flutter/issues/60023
   Future<void> ensureReadyForPlatformSpecificTooling({bool checkProjects = false}) async {
     if (!directory.existsSync() || hasExampleApp) {
       return;
@@ -648,6 +651,7 @@ class IosProject extends FlutterProjectPlatform implements XcodeBasedProject {
     template.render(
       target,
       <String, dynamic>{
+        'ios': true,
         'projectName': parent.manifest.appName,
         'iosIdentifier': parent.manifest.iosBundleIdentifier,
       },
@@ -797,6 +801,7 @@ class AndroidProject extends FlutterProjectPlatform {
     template.render(
       target,
       <String, dynamic>{
+        'android': true,
         'projectName': parent.manifest.appName,
         'androidIdentifier': parent.manifest.androidPackage,
         'androidX': usesAndroidX,

packages/flutter_tools/lib/src/template.dart

@@ -108,6 +108,16 @@ class Template {
         }
         relativeDestinationPath = relativeDestinationPath.replaceAll('$platform-$language.tmpl', platform);
       }
+
+      final bool android = context['android'] as bool;
+      if (relativeDestinationPath.contains('android') && !android) {
+        return null;
+      }
+
+      // TODO(cyanglaz): do not add iOS folder by default when 1.20.0 is released.
+      // Also need to update the flutter SDK min constraint in the pubspec.yaml to 1.20.0.
+      // https://github.com/flutter/flutter/issues/59787
+
       // Only build a web project if explicitly asked.
       final bool web = context['web'] as bool;
       if (relativeDestinationPath.contains('web') && !web) {
@@ -128,6 +138,7 @@ class Template {
       if (relativeDestinationPath.startsWith('windows.tmpl') && !windows) {
         return null;
       }
+
       final String projectName = context['projectName'] as String;
       final String androidIdentifier = context['androidIdentifier'] as String;
       final String pluginClass = context['pluginClass'] as String;
@@ -139,7 +150,7 @@ class Template {
         .replaceAll(imageTemplateExtension, '')
         .replaceAll(templateExtension, '');
 
-      if (androidIdentifier != null) {
+      if (android != null && android && androidIdentifier != null) {
         finalDestinationPath = finalDestinationPath
             .replaceAll('androidIdentifier', androidIdentifier.replaceAll('.', pathSeparator));
       }

packages/flutter_tools/templates/plugin/README.md.tmpl

@@ -9,6 +9,12 @@ This project is a starting point for a Flutter
 a specialized package that includes platform-specific implementation code for
 Android and/or iOS.
 
-For help getting started with Flutter, view our 
-[online documentation](https://flutter.dev/docs), which offers tutorials, 
+For help getting started with Flutter, view our
+[online documentation](https://flutter.dev/docs), which offers tutorials,
 samples, guidance on mobile development, and a full API reference.
+
+{{#no_platforms}}
+The plugin project was generated without specifying the `--platforms` flag, no platforms are currently supported.
+To add platforms, run `flutter create -t plugin --platforms <platforms> .` under the same
+directory. You can also find a detailed instruction on how to add platforms in the `pubspec.yaml` at https://flutter.dev/docs/development/packages-and-plugins/developing-packages#plugin-platforms.
+{{/no_platforms}}

packages/flutter_tools/templates/plugin/lib/projectName.dart.tmpl

+{{#no_platforms}}
+// You have generated a new plugin project without
+// specifying the `--platforms` flag. A plugin project supports no platforms is generated.
+// To add platforms, run `flutter create -t plugin --platforms <platforms> .` under the same
+// directory. You can also find a detailed instruction on how to add platforms in the `pubspec.yaml` at https://flutter.dev/docs/development/packages-and-plugins/developing-packages#plugin-platforms.
+{{/no_platforms}}
+
 import 'dart:async';
 
 import 'package:flutter/services.dart';

packages/flutter_tools/templates/plugin/pubspec.yaml.tmpl

@@ -31,11 +31,25 @@ flutter:
   # adding or updating assets for this project.
   plugin:
     platforms:
+{{#no_platforms}}
+    # This plugin project was generated without specifying any
+    # platforms with the `--platform` argument. If you see the `fake_platform` map below, remove it and
+    # then add platforms following the instruction here:
+    # https://flutter.dev/docs/development/packages-and-plugins/developing-packages#plugin-platforms
+    # -------------------
+      some_platform:
+        pluginClass: somePluginClass
+    # -------------------
+{{/no_platforms}}
+{{#android}}
       android:
         package: {{androidIdentifier}}
         pluginClass: {{pluginClass}}
+{{/android}}
+{{#ios}}
       ios:
         pluginClass: {{pluginClass}}
+{{/ios}}
 {{#linux}}
       linux:
         pluginClass: {{pluginClass}}
@@ -44,6 +58,10 @@ flutter:
       macos:
         pluginClass: {{pluginClass}}
 {{/macos}}
+{{#windows}}
+      windows:
+        pluginClass: {{pluginClass}}
+{{/windows}}
 {{#web}}
       web:
         pluginClass: {{pluginDartClass}}Web

packages/flutter_tools/test/commands.shard/permeable/packages_test.dart

@@ -375,7 +375,7 @@ void main() {
     testUsingContext('get fetches packages and injects plugin in plugin project', () async {
       final String projectPath = await createProject(
         tempDir,
-        arguments: <String>['--template=plugin', '--no-pub'],
+        arguments: <String>['--template=plugin', '--no-pub', '--platforms=ios,android'],
       );
       final String exampleProjectPath = globals.fs.path.join(projectPath, 'example');
       removeGeneratedFiles(projectPath);

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

@@ -900,6 +900,49 @@ flutter:
 
     expect(flutterManifest.isEmpty, false);
   });
+
+  testWithoutContext('FlutterManifest getSupportedPlatforms return null if runs on legacy format', () {
+    const String manifest = '''
+name: test
+flutter:
+  plugin:
+    androidPackage: com.example
+''';
+    final BufferLogger logger = BufferLogger.test();
+    final FlutterManifest flutterManifest = FlutterManifest.createFromString(
+      manifest,
+      logger: logger,
+    );
+
+    expect(flutterManifest.isPlugin, true);
+    expect(flutterManifest.supportedPlatforms, null);
+  });
+
+  testWithoutContext('FlutterManifest getSupportedPlatforms returns valid platforms.', () {
+    const String manifest = '''
+name: test
+flutter:
+  plugin:
+    platforms:
+      android:
+        package: com.example
+        pluginClass: SomeClass
+      ios:
+        pluginClass: SomeClass
+''';
+    final BufferLogger logger = BufferLogger.test();
+    final FlutterManifest flutterManifest = FlutterManifest.createFromString(
+      manifest,
+      logger: logger,
+    );
+
+    expect(flutterManifest.isPlugin, true);
+    expect(flutterManifest.supportedPlatforms['ios'],
+                              <String, dynamic>{'pluginClass': 'SomeClass'});
+    expect(flutterManifest.supportedPlatforms['android'],
+                              <String, dynamic>{'pluginClass': 'SomeClass',
+                                                'package': 'com.example'});
+  });
 }
 
 Matcher matchesManifest({

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

@@ -10,15 +10,18 @@ import 'package:file_testing/file_testing.dart';
 import 'package:flutter_tools/src/base/time.dart';
 import 'package:flutter_tools/src/dart/package_map.dart';
 import 'package:flutter_tools/src/features.dart';
+import 'package:flutter_tools/src/globals.dart' as globals;
 import 'package:flutter_tools/src/ios/xcodeproj.dart';
 import 'package:flutter_tools/src/plugins.dart';
 import 'package:flutter_tools/src/project.dart';
 import 'package:flutter_tools/src/version.dart';
 import 'package:meta/meta.dart';
 import 'package:mockito/mockito.dart';
+import 'package:yaml/yaml.dart';
 
 import '../src/common.dart';
 import '../src/context.dart';
+import '../src/pubspec_schema.dart';
 
 void main() {
   group('plugins', () {
@@ -109,16 +112,14 @@ void main() {
           ..writeAsStringSync('apackage:file://${dummyPackageDirectory.path}\n');
     });
 
-    // Makes the dummy package pointed to by packagesFile look like a plugin.
-    void configureDummyPackageAsPlugin() {
-      dummyPackageDirectory.parent.childFile('pubspec.yaml')..createSync(recursive: true)..writeAsStringSync('''
+    const String _pluginYaml = '''
   flutter:
     plugin:
       platforms:
         ios:
-          pluginClass: FLESomePlugin
+          pluginClass: SomePlugin
         macos:
-          pluginClass: FLESomePlugin
+          pluginClass: SomePlugin
         windows:
           pluginClass: SomePlugin
         linux:
@@ -129,7 +130,10 @@ void main() {
         android:
           pluginClass: SomePlugin
           package: AndroidPackage
-  ''');
+  ''';
+    // Makes the dummy package pointed to by packagesFile look like a plugin.
+    void configureDummyPackageAsPlugin() {
+      dummyPackageDirectory.parent.childFile('pubspec.yaml')..createSync(recursive: true)..writeAsStringSync(_pluginYaml);
     }
 
     void createNewJavaPlugin1() {
@@ -1298,6 +1302,51 @@ flutter:
         FeatureFlags: () => featureFlags,
       });
     });
+
+    group('pubspec', () {
+
+      Directory projectDir;
+      Directory tempDir;
+      setUp(() {
+        tempDir = globals.fs.systemTempDirectory.createTempSync('plugin_test.');
+        projectDir = tempDir.childDirectory('flutter_project');
+      });
+
+      tearDown(() {
+        tryToDelete(tempDir);
+      });
+
+      void _createPubspecFile(String yamlString) {
+        projectDir.childFile('pubspec.yaml')..createSync(recursive: true)..writeAsStringSync(yamlString);
+      }
+
+      test('validatePubspecForPlugin works', () async {
+        _createPubspecFile(_pluginYaml);
+        validatePubspecForPlugin(projectDir: projectDir.absolute.path, pluginClass: 'SomePlugin', expectedPlatforms: <String>[
+          'ios', 'macos', 'windows', 'linux', 'android', 'web'
+        ], androidIdentifier: 'AndroidPackage', webFileName: 'lib/SomeFile.dart');
+      });
+
+      test('createPlatformsYamlMap should create the correct map', () async {
+        final YamlMap map = Plugin.createPlatformsYamlMap(<String>['ios', 'android', 'linux'], 'PluginClass', 'some.android.package');
+        expect(map['ios'], <String, String> {
+          'pluginClass' : 'PluginClass'
+        });
+        expect(map['android'], <String, String> {
+          'pluginClass' : 'PluginClass',
+          'package': 'some.android.package',
+        });
+        expect(map['linux'], <String, String> {
+          'pluginClass' : 'PluginClass'
+        });
+      });
+
+      test('createPlatformsYamlMap should create empty map', () async {
+        final YamlMap map = Plugin.createPlatformsYamlMap(<String>[], null, null);
+        expect(map.isEmpty, true);
+      });
+
+    });
   });
 }
 

packages/flutter_tools/test/src/pubspec_schema.dart

@@ -5,6 +5,10 @@
 import 'package:file/file.dart';
 import 'package:flutter_tools/src/base/file_system.dart';
 import 'package:flutter_tools/src/flutter_manifest.dart';
+import 'package:meta/meta.dart';
+import 'package:flutter_tools/src/globals.dart' as globals;
+import 'package:yaml/yaml.dart';
+import 'common.dart';
 
 /// Writes a schemaData used for validating pubspec.yaml files when parsing
 /// asset information.
@@ -22,3 +26,22 @@ void writeSchemaFile(FileSystem filesystem, String schemaData) {
 void writeEmptySchemaFile(FileSystem filesystem) {
   writeSchemaFile(filesystem, '{}');
 }
+
+/// Check if the pubspec.yaml file under the `projectDir` is valid for a plugin project.
+void validatePubspecForPlugin({@required String projectDir, @required String pluginClass, @required List<String> expectedPlatforms, List<String> unexpectedPlatforms = const <String>[], String androidIdentifier, String webFileName}) {
+    final FlutterManifest manifest = FlutterManifest.createFromPath(projectDir+'/pubspec.yaml', fileSystem: globals.fs, logger: globals.logger);
+    final YamlMap platformsMap = YamlMap.wrap(manifest.supportedPlatforms);
+    for (final String platform in expectedPlatforms) {
+      expect(platformsMap[platform], isNotNull);
+      expect(platformsMap[platform]['pluginClass'], pluginClass);
+      if (platform == 'android') {
+        expect(platformsMap[platform]['package'], androidIdentifier);
+      }
+      if (platform == 'web') {
+        expect(platformsMap[platform]['fileName'], webFileName);
+      }
+    }
+    for (final String platform in unexpectedPlatforms) {
+      expect(platformsMap[platform], isNull);
+    }
+}