[flutter_plugin_tool] Add support for building UWP plugins (#4047)

This allows building UWP plugin examples with `build-examples --winuwp`. As with previous pre-stable-template desktop support, this avoids the issue of unstable app templates by running `flutter create` on the fly before trying to build, so a template that will bitrot doesn't need to be checked in.

Also adds no-op "support" for `drive-examples --winuwp`, with warnings about it not doing anything. This is to handle the fact that the LUCI recipe is shared between Win32 and UWP, and didn't conditionalize `drive`. Rather than change that, then change it back later, this just adds the no-op support now (since changing the tooling is much easier than changing LUCI recipes currently).

This required some supporting tool changes:
- Adds the ability to check for the new platform variants in a pubspec
- Adds the ability to write test pubspecs that include variants, for testing

Part of https://github.com/flutter/flutter/issues/82817

script/tool/CHANGELOG.md

@@ -4,6 +4,7 @@
 - Added a new `android-lint` command to lint Android plugin native code.
 - Pubspec validation now checks for `implements` in implementation packages.
 - Pubspec valitation now checks the full relative path of `repository` entries.
+- `build-examples` now supports UWP plugins via a `--winuwp` flag.
 
 ## 0.5.0
 

script/tool/lib/src/build_examples_command.dart

@@ -16,7 +16,16 @@ import 'common/repository_package.dart';
 /// Key for APK.
 const String _platformFlagApk = 'apk';
 
-const int _exitNoPlatformFlags = 2;
+const int _exitNoPlatformFlags = 3;
+
+// Flutter build types. These are the values passed to `flutter build <foo>`.
+const String _flutterBuildTypeAndroid = 'apk';
+const String _flutterBuildTypeIos = 'ios';
+const String _flutterBuildTypeLinux = 'linux';
+const String _flutterBuildTypeMacOS = 'macos';
+const String _flutterBuildTypeWeb = 'web';
+const String _flutterBuildTypeWin32 = 'windows';
+const String _flutterBuildTypeWinUwp = 'winuwp';
 
 /// A command to build the example applications for packages.
 class BuildExamplesCommand extends PackageLoopingCommand {
@@ -30,6 +39,7 @@ class BuildExamplesCommand extends PackageLoopingCommand {
     argParser.addFlag(kPlatformMacos);
     argParser.addFlag(kPlatformWeb);
     argParser.addFlag(kPlatformWindows);
+    argParser.addFlag(kPlatformWinUwp);
     argParser.addFlag(kPlatformIos);
     argParser.addFlag(_platformFlagApk);
     argParser.addOption(
@@ -46,33 +56,40 @@ class BuildExamplesCommand extends PackageLoopingCommand {
     _platformFlagApk: const _PlatformDetails(
       'Android',
       pluginPlatform: kPlatformAndroid,
-      flutterBuildType: 'apk',
+      flutterBuildType: _flutterBuildTypeAndroid,
     ),
     kPlatformIos: const _PlatformDetails(
       'iOS',
       pluginPlatform: kPlatformIos,
-      flutterBuildType: 'ios',
+      flutterBuildType: _flutterBuildTypeIos,
       extraBuildFlags: <String>['--no-codesign'],
     ),
     kPlatformLinux: const _PlatformDetails(
       'Linux',
       pluginPlatform: kPlatformLinux,
-      flutterBuildType: 'linux',
+      flutterBuildType: _flutterBuildTypeLinux,
     ),
     kPlatformMacos: const _PlatformDetails(
       'macOS',
       pluginPlatform: kPlatformMacos,
-      flutterBuildType: 'macos',
+      flutterBuildType: _flutterBuildTypeMacOS,
     ),
     kPlatformWeb: const _PlatformDetails(
       'web',
       pluginPlatform: kPlatformWeb,
-      flutterBuildType: 'web',
+      flutterBuildType: _flutterBuildTypeWeb,
     ),
     kPlatformWindows: const _PlatformDetails(
-      'Windows',
+      'Win32',
       pluginPlatform: kPlatformWindows,
-      flutterBuildType: 'windows',
+      pluginPlatformVariant: platformVariantWin32,
+      flutterBuildType: _flutterBuildTypeWin32,
+    ),
+    kPlatformWinUwp: const _PlatformDetails(
+      'UWP',
+      pluginPlatform: kPlatformWindows,
+      pluginPlatformVariant: platformVariantWinUwp,
+      flutterBuildType: _flutterBuildTypeWinUwp,
     ),
   };
 
@@ -107,7 +124,8 @@ class BuildExamplesCommand extends PackageLoopingCommand {
     final Set<_PlatformDetails> buildPlatforms = <_PlatformDetails>{};
     final Set<_PlatformDetails> unsupportedPlatforms = <_PlatformDetails>{};
     for (final _PlatformDetails platform in requestedPlatforms) {
-      if (pluginSupportsPlatform(platform.pluginPlatform, package)) {
+      if (pluginSupportsPlatform(platform.pluginPlatform, package,
+          variant: platform.pluginPlatformVariant)) {
         buildPlatforms.add(platform);
       } else {
         unsupportedPlatforms.add(platform);
@@ -156,6 +174,22 @@ class BuildExamplesCommand extends PackageLoopingCommand {
   }) async {
     final String enableExperiment = getStringArg(kEnableExperiment);
 
+    // The UWP template is not yet stable, so the UWP directory
+    // needs to be created on the fly with 'flutter create .'
+    Directory? temporaryPlatformDirectory;
+    if (flutterBuildType == _flutterBuildTypeWinUwp) {
+      final Directory uwpDirectory = example.directory.childDirectory('winuwp');
+      if (!uwpDirectory.existsSync()) {
+        print('Creating temporary winuwp folder');
+        final int exitCode = await processRunner.runAndStream(flutterCommand,
+            <String>['create', '--platforms=$kPlatformWinUwp', '.'],
+            workingDir: example.directory);
+        if (exitCode == 0) {
+          temporaryPlatformDirectory = uwpDirectory;
+        }
+      }
+    }
+
     final int exitCode = await processRunner.runAndStream(
       flutterCommand,
       <String>[
@@ -167,6 +201,13 @@ class BuildExamplesCommand extends PackageLoopingCommand {
       ],
       workingDir: example.directory,
     );
+
+    if (temporaryPlatformDirectory != null &&
+        temporaryPlatformDirectory.existsSync()) {
+      print('Cleaning up ${temporaryPlatformDirectory.path}');
+      temporaryPlatformDirectory.deleteSync(recursive: true);
+    }
+
     return exitCode == 0;
   }
 }
@@ -176,6 +217,7 @@ class _PlatformDetails {
   const _PlatformDetails(
     this.label, {
     required this.pluginPlatform,
+    this.pluginPlatformVariant,
     required this.flutterBuildType,
     this.extraBuildFlags = const <String>[],
   });
@@ -186,6 +228,10 @@ class _PlatformDetails {
   /// The key in a pubspec's platform: entry.
   final String pluginPlatform;
 
+  /// The supportedVariants key under a plugin's [pluginPlatform] entry, if
+  /// applicable.
+  final String? pluginPlatformVariant;
+
   /// The `flutter build` build type.
   final String flutterBuildType;
 

script/tool/lib/src/common/core.dart

@@ -10,24 +10,43 @@ import 'package:yaml/yaml.dart';
 /// print destination.
 typedef Print = void Function(Object? object);
 
-/// Key for windows platform.
+/// Key for APK (Android) platform.
-const String kPlatformWindows = 'windows';
+const String kPlatformAndroid = 'android';
-
-/// Key for macos platform.
-const String kPlatformMacos = 'macos';
-
-/// Key for linux platform.
-const String kPlatformLinux = 'linux';
 
 /// Key for IPA (iOS) platform.
 const String kPlatformIos = 'ios';
 
-/// Key for APK (Android) platform.
+/// Key for linux platform.
-const String kPlatformAndroid = 'android';
+const String kPlatformLinux = 'linux';
+
+/// Key for macos platform.
+const String kPlatformMacos = 'macos';
 
 /// Key for Web platform.
 const String kPlatformWeb = 'web';
 
+/// Key for windows platform.
+///
+/// Note that this corresponds to the Win32 variant for flutter commands like
+/// `build` and `run`, but is a general platform containing all Windows
+/// variants for purposes of the `platform` section of a plugin pubspec).
+const String kPlatformWindows = 'windows';
+
+/// Key for WinUWP platform.
+///
+/// Note that UWP is a platform for the purposes of flutter commands like
+/// `build` and `run`, but a variant of the `windows` platform for the purposes
+/// of plugin pubspecs).
+const String kPlatformWinUwp = 'winuwp';
+
+/// Key for Win32 variant of the Windows platform.
+const String platformVariantWin32 = 'win32';
+
+/// Key for UWP variant of the Windows platform.
+///
+/// See the note on [kPlatformWinUwp].
+const String platformVariantWinUwp = 'uwp';
+
 /// Key for enable experiment.
 const String kEnableExperiment = 'enable-experiment';
 

script/tool/lib/src/common/plugin_utils.dart

@@ -28,8 +28,12 @@ enum PlatformSupport {
 ///
 /// If [requiredMode] is provided, the plugin must have the given type of
 /// implementation in order to return true.
-bool pluginSupportsPlatform(String platform, RepositoryPackage package,
+bool pluginSupportsPlatform(
-    {PlatformSupport? requiredMode}) {
+  String platform,
+  RepositoryPackage package, {
+  PlatformSupport? requiredMode,
+  String? variant,
+}) {
   assert(platform == kPlatformIos ||
       platform == kPlatformAndroid ||
       platform == kPlatformWeb ||
@@ -65,9 +69,34 @@ bool pluginSupportsPlatform(String platform, RepositoryPackage package,
     }
     // If the platform entry is present, then it supports the platform. Check
     // for required mode if specified.
+    if (requiredMode != null) {
       final bool federated = platformEntry.containsKey('default_package');
-    return requiredMode == null ||
+      if (federated != (requiredMode == PlatformSupport.federated)) {
-        federated == (requiredMode == PlatformSupport.federated);
+        return false;
+      }
+    }
+
+    // If a variant is specified, check for that variant.
+    if (variant != null) {
+      const String variantsKey = 'supportedVariants';
+      if (platformEntry.containsKey(variantsKey)) {
+        if (!(platformEntry['supportedVariants']! as YamlList)
+            .contains(variant)) {
+          return false;
+        }
+      } else {
+        // Platforms with variants have a default variant when unspecified for
+        // backward compatibility. Must match the flutter tool logic.
+        const Map<String, String> defaultVariants = <String, String>{
+          kPlatformWindows: platformVariantWin32,
+        };
+        if (variant != defaultVariants[platform]) {
+          return false;
+        }
+      }
+    }
+
+    return true;
   } on FileSystemException {
     return false;
   } on YamlException {

script/tool/lib/src/drive_examples_command.dart

@@ -36,7 +36,10 @@ class DriveExamplesCommand extends PackageLoopingCommand {
     argParser.addFlag(kPlatformWeb,
         help: 'Runs the web implementation of the examples');
     argParser.addFlag(kPlatformWindows,
-        help: 'Runs the Windows implementation of the examples');
+        help: 'Runs the Windows (Win32) implementation of the examples');
+    argParser.addFlag(kPlatformWinUwp,
+        help:
+            'Runs the UWP implementation of the examples [currently a no-op]');
     argParser.addOption(
       kEnableExperiment,
       defaultsTo: '',
@@ -67,6 +70,7 @@ class DriveExamplesCommand extends PackageLoopingCommand {
       kPlatformMacos,
       kPlatformWeb,
       kPlatformWindows,
+      kPlatformWinUwp,
     ];
     final int platformCount = platformSwitches
         .where((String platform) => getBoolArg(platform))
@@ -81,6 +85,10 @@ class DriveExamplesCommand extends PackageLoopingCommand {
       throw ToolExit(_exitNoPlatformFlags);
     }
 
+    if (getBoolArg(kPlatformWinUwp)) {
+      logWarning('Driving UWP applications is not yet supported');
+    }
+
     String? androidDevice;
     if (getBoolArg(kPlatformAndroid)) {
       final List<String> devices = await _getDevicesForPlatform('android');
@@ -116,6 +124,10 @@ class DriveExamplesCommand extends PackageLoopingCommand {
         ],
       if (getBoolArg(kPlatformWindows))
         kPlatformWindows: <String>['-d', 'windows'],
+      // TODO(stuartmorgan): Check these flags once drive supports UWP:
+      // https://github.com/flutter/flutter/issues/82821
+      if (getBoolArg(kPlatformWinUwp))
+        kPlatformWinUwp: <String>['-d', 'winuwp'],
     };
   }
 
@@ -132,7 +144,17 @@ class DriveExamplesCommand extends PackageLoopingCommand {
     final List<String> deviceFlags = <String>[];
     for (final MapEntry<String, List<String>> entry
         in _targetDeviceFlags.entries) {
-      if (pluginSupportsPlatform(entry.key, package)) {
+      final String platform = entry.key;
+      String? variant;
+      if (platform == kPlatformWindows) {
+        variant = platformVariantWin32;
+      } else if (platform == kPlatformWinUwp) {
+        variant = platformVariantWinUwp;
+        // TODO(stuartmorgan): Remove this once drive supports UWP.
+        // https://github.com/flutter/flutter/issues/82821
+        return PackageResult.skip('Drive does not yet support UWP');
+      }
+      if (pluginSupportsPlatform(platform, package, variant: variant)) {
         deviceFlags.addAll(entry.value);
       } else {
         print('Skipping unsupported platform ${entry.key}...');

script/tool/test/build_examples_command_test.dart

@@ -56,8 +56,8 @@ void main() {
 
     test('fails if building fails', () async {
       createFakePlugin('plugin', packagesDir,
-          platformSupport: <String, PlatformSupport>{
+          platformSupport: <String, PlatformDetails>{
-            kPlatformIos: PlatformSupport.inline
+            kPlatformIos: const PlatformDetails(PlatformSupport.inline),
           });
 
       processRunner
@@ -106,8 +106,8 @@ void main() {
     test('building for iOS', () async {
       mockPlatform.isMacOS = true;
       final Directory pluginDirectory = createFakePlugin('plugin', packagesDir,
-          platformSupport: <String, PlatformSupport>{
+          platformSupport: <String, PlatformDetails>{
-            kPlatformIos: PlatformSupport.inline
+            kPlatformIos: const PlatformDetails(PlatformSupport.inline),
           });
 
       final Directory pluginExampleDirectory =
@@ -163,8 +163,8 @@ void main() {
     test('building for Linux', () async {
       mockPlatform.isLinux = true;
       final Directory pluginDirectory = createFakePlugin('plugin', packagesDir,
-          platformSupport: <String, PlatformSupport>{
+          platformSupport: <String, PlatformDetails>{
-            kPlatformLinux: PlatformSupport.inline,
+            kPlatformLinux: const PlatformDetails(PlatformSupport.inline),
           });
 
       final Directory pluginExampleDirectory =
@@ -212,8 +212,8 @@ void main() {
     test('building for macOS', () async {
       mockPlatform.isMacOS = true;
       final Directory pluginDirectory = createFakePlugin('plugin', packagesDir,
-          platformSupport: <String, PlatformSupport>{
+          platformSupport: <String, PlatformDetails>{
-            kPlatformMacos: PlatformSupport.inline,
+            kPlatformMacos: const PlatformDetails(PlatformSupport.inline),
           });
 
       final Directory pluginExampleDirectory =
@@ -258,8 +258,8 @@ void main() {
 
     test('building for web', () async {
       final Directory pluginDirectory = createFakePlugin('plugin', packagesDir,
-          platformSupport: <String, PlatformSupport>{
+          platformSupport: <String, PlatformDetails>{
-            kPlatformWeb: PlatformSupport.inline,
+            kPlatformWeb: const PlatformDetails(PlatformSupport.inline),
           });
 
       final Directory pluginExampleDirectory =
@@ -284,7 +284,7 @@ void main() {
     });
 
     test(
-        'building for Windows when plugin is not set up for Windows results in no-op',
+        'building for win32 when plugin is not set up for Windows results in no-op',
         () async {
       mockPlatform.isWindows = true;
       createFakePlugin('plugin', packagesDir);
@@ -296,7 +296,7 @@ void main() {
         output,
         containsAllInOrder(<Matcher>[
           contains('Running for plugin'),
-          contains('Windows is not supported by this plugin'),
+          contains('Win32 is not supported by this plugin'),
         ]),
       );
 
@@ -305,11 +305,11 @@ void main() {
       expect(processRunner.recordedCalls, orderedEquals(<ProcessCall>[]));
     });
 
-    test('building for Windows', () async {
+    test('building for win32', () async {
       mockPlatform.isWindows = true;
       final Directory pluginDirectory = createFakePlugin('plugin', packagesDir,
-          platformSupport: <String, PlatformSupport>{
+          platformSupport: <String, PlatformDetails>{
-            kPlatformWindows: PlatformSupport.inline
+            kPlatformWindows: const PlatformDetails(PlatformSupport.inline),
           });
 
       final Directory pluginExampleDirectory =
@@ -321,7 +321,7 @@ void main() {
       expect(
         output,
         containsAllInOrder(<String>[
-          '\nBUILDING plugin/example for Windows',
+          '\nBUILDING plugin/example for Win32 (windows)',
         ]),
       );
 
@@ -335,6 +335,91 @@ void main() {
           ]));
     });
 
+    test('building for UWP when plugin does not support UWP is a no-op',
+        () async {
+      createFakePlugin('plugin', packagesDir);
+
+      final List<String> output = await runCapturingPrint(
+          runner, <String>['build-examples', '--winuwp']);
+
+      expect(
+        output,
+        containsAllInOrder(<Matcher>[
+          contains('Running for plugin'),
+          contains('UWP is not supported by this plugin'),
+        ]),
+      );
+
+      print(processRunner.recordedCalls);
+      // Output should be empty since running build-examples --macos with no macos
+      // implementation is a no-op.
+      expect(processRunner.recordedCalls, orderedEquals(<ProcessCall>[]));
+    });
+
+    test('building for UWP', () async {
+      final Directory pluginDirectory =
+          createFakePlugin('plugin', packagesDir, extraFiles: <String>[
+        'example/test',
+      ], platformSupport: <String, PlatformDetails>{
+        kPlatformWindows: const PlatformDetails(PlatformSupport.federated,
+            variants: <String>[platformVariantWinUwp]),
+      });
+
+      final Directory pluginExampleDirectory =
+          pluginDirectory.childDirectory('example');
+
+      final List<String> output = await runCapturingPrint(
+          runner, <String>['build-examples', '--winuwp']);
+
+      expect(
+        output,
+        containsAllInOrder(<Matcher>[
+          contains('BUILDING plugin/example for UWP (winuwp)'),
+        ]),
+      );
+
+      print(processRunner.recordedCalls);
+      expect(
+          processRunner.recordedCalls,
+          containsAll(<ProcessCall>[
+            ProcessCall(getFlutterCommand(mockPlatform),
+                const <String>['build', 'winuwp'], pluginExampleDirectory.path),
+          ]));
+    });
+
+    test('building for UWP creates a folder if necessary', () async {
+      final Directory pluginDirectory =
+          createFakePlugin('plugin', packagesDir, extraFiles: <String>[
+        'example/test',
+      ], platformSupport: <String, PlatformDetails>{
+        kPlatformWindows: const PlatformDetails(PlatformSupport.federated,
+            variants: <String>[platformVariantWinUwp]),
+      });
+
+      final Directory pluginExampleDirectory =
+          pluginDirectory.childDirectory('example');
+
+      final List<String> output = await runCapturingPrint(
+          runner, <String>['build-examples', '--winuwp']);
+
+      expect(
+        output,
+        contains('Creating temporary winuwp folder'),
+      );
+
+      print(processRunner.recordedCalls);
+      expect(
+          processRunner.recordedCalls,
+          orderedEquals(<ProcessCall>[
+            ProcessCall(
+                getFlutterCommand(mockPlatform),
+                const <String>['create', '--platforms=winuwp', '.'],
+                pluginExampleDirectory.path),
+            ProcessCall(getFlutterCommand(mockPlatform),
+                const <String>['build', 'winuwp'], pluginExampleDirectory.path),
+          ]));
+    });
+
     test(
         'building for Android when plugin is not set up for Android results in no-op',
         () async {
@@ -358,8 +443,8 @@ void main() {
 
     test('building for Android', () async {
       final Directory pluginDirectory = createFakePlugin('plugin', packagesDir,
-          platformSupport: <String, PlatformSupport>{
+          platformSupport: <String, PlatformDetails>{
-            kPlatformAndroid: PlatformSupport.inline
+            kPlatformAndroid: const PlatformDetails(PlatformSupport.inline),
           });
 
       final Directory pluginExampleDirectory =
@@ -387,8 +472,8 @@ void main() {
 
     test('enable-experiment flag for Android', () async {
       final Directory pluginDirectory = createFakePlugin('plugin', packagesDir,
-          platformSupport: <String, PlatformSupport>{
+          platformSupport: <String, PlatformDetails>{
-            kPlatformAndroid: PlatformSupport.inline
+            kPlatformAndroid: const PlatformDetails(PlatformSupport.inline),
           });
 
       final Directory pluginExampleDirectory =
@@ -409,8 +494,8 @@ void main() {
 
     test('enable-experiment flag for ios', () async {
       final Directory pluginDirectory = createFakePlugin('plugin', packagesDir,
-          platformSupport: <String, PlatformSupport>{
+          platformSupport: <String, PlatformDetails>{
-            kPlatformIos: PlatformSupport.inline
+            kPlatformIos: const PlatformDetails(PlatformSupport.inline),
           });
 
       final Directory pluginExampleDirectory =

script/tool/test/common/plugin_utils_test.dart

@@ -36,13 +36,13 @@ void main() {
     test('all platforms', () async {
       final RepositoryPackage plugin = RepositoryPackage(createFakePlugin(
           'plugin', packagesDir,
-          platformSupport: <String, PlatformSupport>{
+          platformSupport: <String, PlatformDetails>{
-            kPlatformAndroid: PlatformSupport.inline,
+            kPlatformAndroid: const PlatformDetails(PlatformSupport.inline),
-            kPlatformIos: PlatformSupport.inline,
+            kPlatformIos: const PlatformDetails(PlatformSupport.inline),
-            kPlatformLinux: PlatformSupport.inline,
+            kPlatformLinux: const PlatformDetails(PlatformSupport.inline),
-            kPlatformMacos: PlatformSupport.inline,
+            kPlatformMacos: const PlatformDetails(PlatformSupport.inline),
-            kPlatformWeb: PlatformSupport.inline,
+            kPlatformWeb: const PlatformDetails(PlatformSupport.inline),
-            kPlatformWindows: PlatformSupport.inline,
+            kPlatformWindows: const PlatformDetails(PlatformSupport.inline),
           }));
 
       expect(pluginSupportsPlatform(kPlatformAndroid, plugin), isTrue);
@@ -55,14 +55,12 @@ void main() {
 
     test('some platforms', () async {
       final RepositoryPackage plugin = RepositoryPackage(createFakePlugin(
-        'plugin',
+          'plugin', packagesDir,
-        packagesDir,
+          platformSupport: <String, PlatformDetails>{
-        platformSupport: <String, PlatformSupport>{
+            kPlatformAndroid: const PlatformDetails(PlatformSupport.inline),
-          kPlatformAndroid: PlatformSupport.inline,
+            kPlatformLinux: const PlatformDetails(PlatformSupport.inline),
-          kPlatformLinux: PlatformSupport.inline,
+            kPlatformWeb: const PlatformDetails(PlatformSupport.inline),
-          kPlatformWeb: PlatformSupport.inline,
+          }));
-        },
-      ));
 
       expect(pluginSupportsPlatform(kPlatformAndroid, plugin), isTrue);
       expect(pluginSupportsPlatform(kPlatformIos, plugin), isFalse);
@@ -74,17 +72,15 @@ void main() {
 
     test('inline plugins are only detected as inline', () async {
       final RepositoryPackage plugin = RepositoryPackage(createFakePlugin(
-        'plugin',
+          'plugin', packagesDir,
-        packagesDir,
+          platformSupport: <String, PlatformDetails>{
-        platformSupport: <String, PlatformSupport>{
+            kPlatformAndroid: const PlatformDetails(PlatformSupport.inline),
-          kPlatformAndroid: PlatformSupport.inline,
+            kPlatformIos: const PlatformDetails(PlatformSupport.inline),
-          kPlatformIos: PlatformSupport.inline,
+            kPlatformLinux: const PlatformDetails(PlatformSupport.inline),
-          kPlatformLinux: PlatformSupport.inline,
+            kPlatformMacos: const PlatformDetails(PlatformSupport.inline),
-          kPlatformMacos: PlatformSupport.inline,
+            kPlatformWeb: const PlatformDetails(PlatformSupport.inline),
-          kPlatformWeb: PlatformSupport.inline,
+            kPlatformWindows: const PlatformDetails(PlatformSupport.inline),
-          kPlatformWindows: PlatformSupport.inline,
+          }));
-        },
-      ));
 
       expect(
           pluginSupportsPlatform(kPlatformAndroid, plugin,
@@ -137,19 +133,16 @@ void main() {
     });
 
     test('federated plugins are only detected as federated', () async {
-      const String pluginName = 'plugin';
       final RepositoryPackage plugin = RepositoryPackage(createFakePlugin(
-        pluginName,
+          'plugin', packagesDir,
-        packagesDir,
+          platformSupport: <String, PlatformDetails>{
-        platformSupport: <String, PlatformSupport>{
+            kPlatformAndroid: const PlatformDetails(PlatformSupport.federated),
-          kPlatformAndroid: PlatformSupport.federated,
+            kPlatformIos: const PlatformDetails(PlatformSupport.federated),
-          kPlatformIos: PlatformSupport.federated,
+            kPlatformLinux: const PlatformDetails(PlatformSupport.federated),
-          kPlatformLinux: PlatformSupport.federated,
+            kPlatformMacos: const PlatformDetails(PlatformSupport.federated),
-          kPlatformMacos: PlatformSupport.federated,
+            kPlatformWeb: const PlatformDetails(PlatformSupport.federated),
-          kPlatformWeb: PlatformSupport.federated,
+            kPlatformWindows: const PlatformDetails(PlatformSupport.federated),
-          kPlatformWindows: PlatformSupport.federated,
+          }));
-        },
-      ));
 
       expect(
           pluginSupportsPlatform(kPlatformAndroid, plugin,
@@ -200,5 +193,84 @@ void main() {
               requiredMode: PlatformSupport.inline),
           isFalse);
     });
+
+    test('windows without variants is only win32', () async {
+      final RepositoryPackage plugin = RepositoryPackage(createFakePlugin(
+        'plugin',
+        packagesDir,
+        platformSupport: <String, PlatformDetails>{
+          kPlatformWindows: const PlatformDetails(PlatformSupport.inline),
+        },
+      ));
+
+      expect(
+          pluginSupportsPlatform(kPlatformWindows, plugin,
+              variant: platformVariantWin32),
+          isTrue);
+      expect(
+          pluginSupportsPlatform(kPlatformWindows, plugin,
+              variant: platformVariantWinUwp),
+          isFalse);
+    });
+
+    test('windows with both variants matches win32 and winuwp', () async {
+      final RepositoryPackage plugin = RepositoryPackage(createFakePlugin(
+          'plugin', packagesDir,
+          platformSupport: <String, PlatformDetails>{
+            kPlatformWindows: const PlatformDetails(
+              PlatformSupport.federated,
+              variants: <String>[platformVariantWin32, platformVariantWinUwp],
+            ),
+          }));
+
+      expect(
+          pluginSupportsPlatform(kPlatformWindows, plugin,
+              variant: platformVariantWin32),
+          isTrue);
+      expect(
+          pluginSupportsPlatform(kPlatformWindows, plugin,
+              variant: platformVariantWinUwp),
+          isTrue);
+    });
+
+    test('win32 plugin is only win32', () async {
+      final RepositoryPackage plugin = RepositoryPackage(createFakePlugin(
+          'plugin', packagesDir,
+          platformSupport: <String, PlatformDetails>{
+            kPlatformWindows: const PlatformDetails(
+              PlatformSupport.federated,
+              variants: <String>[platformVariantWin32],
+            ),
+          }));
+
+      expect(
+          pluginSupportsPlatform(kPlatformWindows, plugin,
+              variant: platformVariantWin32),
+          isTrue);
+      expect(
+          pluginSupportsPlatform(kPlatformWindows, plugin,
+              variant: platformVariantWinUwp),
+          isFalse);
+    });
+
+    test('winup plugin is only winuwp', () async {
+      final RepositoryPackage plugin = RepositoryPackage(createFakePlugin(
+        'plugin',
+        packagesDir,
+        platformSupport: <String, PlatformDetails>{
+          kPlatformWindows: const PlatformDetails(PlatformSupport.federated,
+              variants: <String>[platformVariantWinUwp]),
+        },
+      ));
+
+      expect(
+          pluginSupportsPlatform(kPlatformWindows, plugin,
+              variant: platformVariantWin32),
+          isFalse);
+      expect(
+          pluginSupportsPlatform(kPlatformWindows, plugin,
+              variant: platformVariantWinUwp),
+          isTrue);
+    });
   });
 }

script/tool/test/create_all_plugins_app_command_test.dart

@@ -21,7 +21,7 @@ void main() {
     setUp(() {
       // Since the core of this command is a call to 'flutter create', the test
       // has to use the real filesystem. Put everything possible in a unique
-      // temporary to minimize affect on the host system.
+      // temporary to minimize effect on the host system.
       fileSystem = const LocalFileSystem();
       testRoot = fileSystem.systemTempDirectory.createTempSync();
       packagesDir = testRoot.childDirectory('packages');

script/tool/test/drive_examples_command_test.dart

@@ -127,8 +127,8 @@ void main() {
           'example/test_driver/integration_test.dart',
           'example/integration_test/foo_test.dart',
         ],
-        platformSupport: <String, PlatformSupport>{
+        platformSupport: <String, PlatformDetails>{
-          kPlatformIos: PlatformSupport.inline,
+          kPlatformIos: const PlatformDetails(PlatformSupport.inline),
         },
       );
 
@@ -192,9 +192,9 @@ void main() {
           'example/test_driver/plugin_test.dart',
           'example/test_driver/plugin.dart',
         ],
-        platformSupport: <String, PlatformSupport>{
+        platformSupport: <String, PlatformDetails>{
-          kPlatformAndroid: PlatformSupport.inline,
+          kPlatformAndroid: const PlatformDetails(PlatformSupport.inline),
-          kPlatformIos: PlatformSupport.inline,
+          kPlatformIos: const PlatformDetails(PlatformSupport.inline),
         },
       );
 
@@ -242,9 +242,9 @@ void main() {
         extraFiles: <String>[
           'example/test_driver/plugin_test.dart',
         ],
-        platformSupport: <String, PlatformSupport>{
+        platformSupport: <String, PlatformDetails>{
-          kPlatformAndroid: PlatformSupport.inline,
+          kPlatformAndroid: const PlatformDetails(PlatformSupport.inline),
-          kPlatformIos: PlatformSupport.inline,
+          kPlatformIos: const PlatformDetails(PlatformSupport.inline),
         },
       );
 
@@ -275,9 +275,9 @@ void main() {
         extraFiles: <String>[
           'example/lib/main.dart',
         ],
-        platformSupport: <String, PlatformSupport>{
+        platformSupport: <String, PlatformDetails>{
-          kPlatformAndroid: PlatformSupport.inline,
+          kPlatformAndroid: const PlatformDetails(PlatformSupport.inline),
-          kPlatformIos: PlatformSupport.inline,
+          kPlatformIos: const PlatformDetails(PlatformSupport.inline),
         },
       );
 
@@ -311,9 +311,9 @@ void main() {
           'example/integration_test/foo_test.dart',
           'example/integration_test/ignore_me.dart',
         ],
-        platformSupport: <String, PlatformSupport>{
+        platformSupport: <String, PlatformDetails>{
-          kPlatformAndroid: PlatformSupport.inline,
+          kPlatformAndroid: const PlatformDetails(PlatformSupport.inline),
-          kPlatformIos: PlatformSupport.inline,
+          kPlatformIos: const PlatformDetails(PlatformSupport.inline),
         },
       );
 
@@ -397,8 +397,8 @@ void main() {
           'example/test_driver/plugin_test.dart',
           'example/test_driver/plugin.dart',
         ],
-        platformSupport: <String, PlatformSupport>{
+        platformSupport: <String, PlatformDetails>{
-          kPlatformLinux: PlatformSupport.inline,
+          kPlatformLinux: const PlatformDetails(PlatformSupport.inline),
         },
       );
 
@@ -470,8 +470,8 @@ void main() {
           'example/test_driver/plugin.dart',
           'example/macos/macos.swift',
         ],
-        platformSupport: <String, PlatformSupport>{
+        platformSupport: <String, PlatformDetails>{
-          kPlatformMacos: PlatformSupport.inline,
+          kPlatformMacos: const PlatformDetails(PlatformSupport.inline),
         },
       );
 
@@ -541,8 +541,8 @@ void main() {
           'example/test_driver/plugin_test.dart',
           'example/test_driver/plugin.dart',
         ],
-        platformSupport: <String, PlatformSupport>{
+        platformSupport: <String, PlatformDetails>{
-          kPlatformWeb: PlatformSupport.inline,
+          kPlatformWeb: const PlatformDetails(PlatformSupport.inline),
         },
       );
 
@@ -615,8 +615,8 @@ void main() {
           'example/test_driver/plugin_test.dart',
           'example/test_driver/plugin.dart',
         ],
-        platformSupport: <String, PlatformSupport>{
+        platformSupport: <String, PlatformDetails>{
-          kPlatformWindows: PlatformSupport.inline
+          kPlatformWindows: const PlatformDetails(PlatformSupport.inline),
         },
       );
 
@@ -654,6 +654,40 @@ void main() {
           ]));
     });
 
+    test('driving UWP is a no-op', () async {
+      createFakePlugin(
+        'plugin',
+        packagesDir,
+        extraFiles: <String>[
+          'example/test_driver/plugin_test.dart',
+          'example/test_driver/plugin.dart',
+        ],
+        platformSupport: <String, PlatformDetails>{
+          kPlatformWindows: const PlatformDetails(PlatformSupport.inline,
+              variants: <String>[platformVariantWinUwp]),
+        },
+      );
+
+      final List<String> output = await runCapturingPrint(runner, <String>[
+        'drive-examples',
+        '--winuwp',
+      ]);
+
+      expect(
+        output,
+        containsAllInOrder(<Matcher>[
+          contains('Driving UWP applications is not yet supported'),
+          contains('Running for plugin'),
+          contains('SKIPPING: Drive does not yet support UWP'),
+          contains('No issues found!'),
+        ]),
+      );
+
+      // Output should be empty since running drive-examples --windows on a
+      // non-Windows plugin is a no-op.
+      expect(processRunner.recordedCalls, <ProcessCall>[]);
+    });
+
     test('driving on an Android plugin', () async {
       final Directory pluginDirectory = createFakePlugin(
         'plugin',
@@ -662,8 +696,8 @@ void main() {
           'example/test_driver/plugin_test.dart',
           'example/test_driver/plugin.dart',
         ],
-        platformSupport: <String, PlatformSupport>{
+        platformSupport: <String, PlatformDetails>{
-          kPlatformAndroid: PlatformSupport.inline,
+          kPlatformAndroid: const PlatformDetails(PlatformSupport.inline),
         },
       );
 
@@ -712,8 +746,8 @@ void main() {
           'example/test_driver/plugin_test.dart',
           'example/test_driver/plugin.dart',
         ],
-        platformSupport: <String, PlatformSupport>{
+        platformSupport: <String, PlatformDetails>{
-          kPlatformMacos: PlatformSupport.inline,
+          kPlatformMacos: const PlatformDetails(PlatformSupport.inline),
         },
       );
 
@@ -745,8 +779,8 @@ void main() {
           'example/test_driver/plugin_test.dart',
           'example/test_driver/plugin.dart',
         ],
-        platformSupport: <String, PlatformSupport>{
+        platformSupport: <String, PlatformDetails>{
-          kPlatformMacos: PlatformSupport.inline,
+          kPlatformMacos: const PlatformDetails(PlatformSupport.inline),
         },
       );
 
@@ -800,9 +834,9 @@ void main() {
           'example/test_driver/plugin_test.dart',
           'example/test_driver/plugin.dart',
         ],
-        platformSupport: <String, PlatformSupport>{
+        platformSupport: <String, PlatformDetails>{
-          kPlatformAndroid: PlatformSupport.inline,
+          kPlatformAndroid: const PlatformDetails(PlatformSupport.inline),
-          kPlatformIos: PlatformSupport.inline,
+          kPlatformIos: const PlatformDetails(PlatformSupport.inline),
         },
       );
 
@@ -842,8 +876,8 @@ void main() {
         'plugin',
         packagesDir,
         examples: <String>[],
-        platformSupport: <String, PlatformSupport>{
+        platformSupport: <String, PlatformDetails>{
-          kPlatformWeb: PlatformSupport.inline,
+          kPlatformWeb: const PlatformDetails(PlatformSupport.inline),
         },
       );
 
@@ -874,8 +908,8 @@ void main() {
           'example/integration_test/bar_test.dart',
           'example/integration_test/foo_test.dart',
         ],
-        platformSupport: <String, PlatformSupport>{
+        platformSupport: <String, PlatformDetails>{
-          kPlatformWeb: PlatformSupport.inline,
+          kPlatformWeb: const PlatformDetails(PlatformSupport.inline),
         },
       );
 
@@ -906,8 +940,8 @@ void main() {
         extraFiles: <String>[
           'example/test_driver/integration_test.dart',
         ],
-        platformSupport: <String, PlatformSupport>{
+        platformSupport: <String, PlatformDetails>{
-          kPlatformWeb: PlatformSupport.inline,
+          kPlatformWeb: const PlatformDetails(PlatformSupport.inline),
         },
       );
 
@@ -942,8 +976,8 @@ void main() {
           'example/integration_test/bar_test.dart',
           'example/integration_test/foo_test.dart',
         ],
-        platformSupport: <String, PlatformSupport>{
+        platformSupport: <String, PlatformDetails>{
-          kPlatformMacos: PlatformSupport.inline,
+          kPlatformMacos: const PlatformDetails(PlatformSupport.inline),
         },
       );
 

script/tool/test/lint_android_command_test.dart

@@ -43,8 +43,8 @@ void main() {
       final Directory pluginDir =
           createFakePlugin('plugin1', packagesDir, extraFiles: <String>[
         'example/android/gradlew',
-      ], platformSupport: <String, PlatformSupport>{
+      ], platformSupport: <String, PlatformDetails>{
-        kPlatformAndroid: PlatformSupport.inline
+        kPlatformAndroid: const PlatformDetails(PlatformSupport.inline)
       });
 
       final Directory androidDir =
@@ -74,8 +74,8 @@ void main() {
 
     test('fails if gradlew is missing', () async {
       createFakePlugin('plugin1', packagesDir,
-          platformSupport: <String, PlatformSupport>{
+          platformSupport: <String, PlatformDetails>{
-            kPlatformAndroid: PlatformSupport.inline
+            kPlatformAndroid: const PlatformDetails(PlatformSupport.inline)
           });
 
       Error? commandError;
@@ -96,8 +96,8 @@ void main() {
 
     test('fails if linting finds issues', () async {
       createFakePlugin('plugin1', packagesDir,
-          platformSupport: <String, PlatformSupport>{
+          platformSupport: <String, PlatformDetails>{
-            kPlatformAndroid: PlatformSupport.inline
+            kPlatformAndroid: const PlatformDetails(PlatformSupport.inline)
           });
 
       processRunner.mockProcessesForExecutable['gradlew'] = <io.Process>[
@@ -138,8 +138,8 @@ void main() {
 
     test('skips non-inline plugins', () async {
       createFakePlugin('plugin1', packagesDir,
-          platformSupport: <String, PlatformSupport>{
+          platformSupport: <String, PlatformDetails>{
-            kPlatformAndroid: PlatformSupport.federated
+            kPlatformAndroid: const PlatformDetails(PlatformSupport.federated)
           });
 
       final List<String> output =

script/tool/test/native_test_command_test.dart

@@ -115,8 +115,8 @@ void main() {
 
     test('reports skips with no tests', () async {
       final Directory pluginDirectory1 = createFakePlugin('plugin', packagesDir,
-          platformSupport: <String, PlatformSupport>{
+          platformSupport: <String, PlatformDetails>{
-            kPlatformMacos: PlatformSupport.inline,
+            kPlatformMacos: const PlatformDetails(PlatformSupport.inline),
           });
 
       final Directory pluginExampleDirectory =
@@ -154,8 +154,8 @@ void main() {
     group('iOS', () {
       test('skip if iOS is not supported', () async {
         createFakePlugin('plugin', packagesDir,
-            platformSupport: <String, PlatformSupport>{
+            platformSupport: <String, PlatformDetails>{
-              kPlatformMacos: PlatformSupport.inline,
+              kPlatformMacos: const PlatformDetails(PlatformSupport.inline),
             });
 
         final List<String> output = await runCapturingPrint(runner,
@@ -171,8 +171,8 @@ void main() {
 
       test('skip if iOS is implemented in a federated package', () async {
         createFakePlugin('plugin', packagesDir,
-            platformSupport: <String, PlatformSupport>{
+            platformSupport: <String, PlatformDetails>{
-              kPlatformIos: PlatformSupport.federated
+              kPlatformIos: const PlatformDetails(PlatformSupport.federated)
             });
 
         final List<String> output = await runCapturingPrint(runner,
@@ -188,8 +188,8 @@ void main() {
 
       test('running with correct destination', () async {
         final Directory pluginDirectory = createFakePlugin(
-            'plugin', packagesDir, platformSupport: <String, PlatformSupport>{
+            'plugin', packagesDir, platformSupport: <String, PlatformDetails>{
-          kPlatformIos: PlatformSupport.inline
+          kPlatformIos: const PlatformDetails(PlatformSupport.inline)
         });
 
         final Directory pluginExampleDirectory =
@@ -234,8 +234,8 @@ void main() {
       test('Not specifying --ios-destination assigns an available simulator',
           () async {
         final Directory pluginDirectory = createFakePlugin(
-            'plugin', packagesDir, platformSupport: <String, PlatformSupport>{
+            'plugin', packagesDir, platformSupport: <String, PlatformDetails>{
-          kPlatformIos: PlatformSupport.inline
+          kPlatformIos: const PlatformDetails(PlatformSupport.inline)
         });
         final Directory pluginExampleDirectory =
             pluginDirectory.childDirectory('example');
@@ -298,8 +298,8 @@ void main() {
 
       test('skip if macOS is implemented in a federated package', () async {
         createFakePlugin('plugin', packagesDir,
-            platformSupport: <String, PlatformSupport>{
+            platformSupport: <String, PlatformDetails>{
-              kPlatformMacos: PlatformSupport.federated,
+              kPlatformMacos: const PlatformDetails(PlatformSupport.federated),
             });
 
         final List<String> output =
@@ -317,8 +317,8 @@ void main() {
       test('runs for macOS plugin', () async {
         final Directory pluginDirectory1 = createFakePlugin(
             'plugin', packagesDir,
-            platformSupport: <String, PlatformSupport>{
+            platformSupport: <String, PlatformDetails>{
-              kPlatformMacos: PlatformSupport.inline,
+              kPlatformMacos: const PlatformDetails(PlatformSupport.inline),
             });
 
         final Directory pluginExampleDirectory =
@@ -360,8 +360,8 @@ void main() {
         final Directory plugin = createFakePlugin(
           'plugin',
           packagesDir,
-          platformSupport: <String, PlatformSupport>{
+          platformSupport: <String, PlatformDetails>{
-            kPlatformAndroid: PlatformSupport.inline
+            kPlatformAndroid: const PlatformDetails(PlatformSupport.inline)
           },
           extraFiles: <String>[
             'example/android/gradlew',
@@ -390,8 +390,8 @@ void main() {
         final Directory plugin = createFakePlugin(
           'plugin',
           packagesDir,
-          platformSupport: <String, PlatformSupport>{
+          platformSupport: <String, PlatformDetails>{
-            kPlatformAndroid: PlatformSupport.inline
+            kPlatformAndroid: const PlatformDetails(PlatformSupport.inline)
           },
           extraFiles: <String>[
             'example/android/gradlew',
@@ -420,8 +420,8 @@ void main() {
         final Directory plugin = createFakePlugin(
           'plugin',
           packagesDir,
-          platformSupport: <String, PlatformSupport>{
+          platformSupport: <String, PlatformDetails>{
-            kPlatformAndroid: PlatformSupport.inline
+            kPlatformAndroid: const PlatformDetails(PlatformSupport.inline)
           },
           extraFiles: <String>[
             'example/android/gradlew',
@@ -455,8 +455,8 @@ void main() {
         createFakePlugin(
           'plugin',
           packagesDir,
-          platformSupport: <String, PlatformSupport>{
+          platformSupport: <String, PlatformDetails>{
-            kPlatformAndroid: PlatformSupport.inline
+            kPlatformAndroid: const PlatformDetails(PlatformSupport.inline)
           },
           extraFiles: <String>[
             'example/android/gradlew',
@@ -480,8 +480,8 @@ void main() {
         final Directory plugin = createFakePlugin(
           'plugin',
           packagesDir,
-          platformSupport: <String, PlatformSupport>{
+          platformSupport: <String, PlatformDetails>{
-            kPlatformAndroid: PlatformSupport.inline
+            kPlatformAndroid: const PlatformDetails(PlatformSupport.inline)
           },
           extraFiles: <String>[
             'android/src/test/example_test.java',
@@ -519,8 +519,8 @@ void main() {
         final Directory plugin = createFakePlugin(
           'plugin',
           packagesDir,
-          platformSupport: <String, PlatformSupport>{
+          platformSupport: <String, PlatformDetails>{
-            kPlatformAndroid: PlatformSupport.inline
+            kPlatformAndroid: const PlatformDetails(PlatformSupport.inline)
           },
           extraFiles: <String>[
             'android/src/test/example_test.java',
@@ -554,8 +554,8 @@ void main() {
         final Directory plugin = createFakePlugin(
           'plugin',
           packagesDir,
-          platformSupport: <String, PlatformSupport>{
+          platformSupport: <String, PlatformDetails>{
-            kPlatformAndroid: PlatformSupport.inline
+            kPlatformAndroid: const PlatformDetails(PlatformSupport.inline)
           },
           extraFiles: <String>[
             'android/src/test/example_test.java',
@@ -586,8 +586,8 @@ void main() {
         createFakePlugin(
           'plugin',
           packagesDir,
-          platformSupport: <String, PlatformSupport>{
+          platformSupport: <String, PlatformDetails>{
-            kPlatformAndroid: PlatformSupport.inline
+            kPlatformAndroid: const PlatformDetails(PlatformSupport.inline)
           },
           extraFiles: <String>[
             'example/android/app/src/test/example_test.java',
@@ -618,8 +618,8 @@ void main() {
         createFakePlugin(
           'plugin1',
           packagesDir,
-          platformSupport: <String, PlatformSupport>{
+          platformSupport: <String, PlatformDetails>{
-            kPlatformAndroid: PlatformSupport.inline
+            kPlatformAndroid: const PlatformDetails(PlatformSupport.inline)
           },
           extraFiles: <String>[
             'example/android/gradlew',
@@ -630,8 +630,8 @@ void main() {
         createFakePlugin(
           'plugin2',
           packagesDir,
-          platformSupport: <String, PlatformSupport>{
+          platformSupport: <String, PlatformDetails>{
-            kPlatformAndroid: PlatformSupport.inline
+            kPlatformAndroid: const PlatformDetails(PlatformSupport.inline)
           },
           extraFiles: <String>[
             'android/src/test/example_test.java',
@@ -657,8 +657,8 @@ void main() {
         final Directory pluginDir = createFakePlugin(
           'plugin',
           packagesDir,
-          platformSupport: <String, PlatformSupport>{
+          platformSupport: <String, PlatformDetails>{
-            kPlatformAndroid: PlatformSupport.inline
+            kPlatformAndroid: const PlatformDetails(PlatformSupport.inline)
           },
           extraFiles: <String>[
             'example/android/gradlew',
@@ -716,8 +716,8 @@ void main() {
         createFakePlugin(
           'plugin',
           packagesDir,
-          platformSupport: <String, PlatformSupport>{
+          platformSupport: <String, PlatformDetails>{
-            kPlatformAndroid: PlatformSupport.inline
+            kPlatformAndroid: const PlatformDetails(PlatformSupport.inline)
           },
         );
 
@@ -739,8 +739,8 @@ void main() {
     group('iOS/macOS', () {
       test('fails if xcrun fails', () async {
         createFakePlugin('plugin', packagesDir,
-            platformSupport: <String, PlatformSupport>{
+            platformSupport: <String, PlatformDetails>{
-              kPlatformMacos: PlatformSupport.inline,
+              kPlatformMacos: const PlatformDetails(PlatformSupport.inline),
             });
 
         processRunner.mockProcessesForExecutable['xcrun'] = <io.Process>[
@@ -767,8 +767,8 @@ void main() {
       test('honors unit-only', () async {
         final Directory pluginDirectory1 = createFakePlugin(
             'plugin', packagesDir,
-            platformSupport: <String, PlatformSupport>{
+            platformSupport: <String, PlatformDetails>{
-              kPlatformMacos: PlatformSupport.inline,
+              kPlatformMacos: const PlatformDetails(PlatformSupport.inline),
             });
 
         final Directory pluginExampleDirectory =
@@ -832,8 +832,8 @@ void main() {
       test('honors integration-only', () async {
         final Directory pluginDirectory1 = createFakePlugin(
             'plugin', packagesDir,
-            platformSupport: <String, PlatformSupport>{
+            platformSupport: <String, PlatformDetails>{
-              kPlatformMacos: PlatformSupport.inline,
+              kPlatformMacos: const PlatformDetails(PlatformSupport.inline),
             });
 
         final Directory pluginExampleDirectory =
@@ -897,8 +897,8 @@ void main() {
       test('skips when the requested target is not present', () async {
         final Directory pluginDirectory1 = createFakePlugin(
             'plugin', packagesDir,
-            platformSupport: <String, PlatformSupport>{
+            platformSupport: <String, PlatformDetails>{
-              kPlatformMacos: PlatformSupport.inline,
+              kPlatformMacos: const PlatformDetails(PlatformSupport.inline),
             });
 
         final Directory pluginExampleDirectory =
@@ -950,8 +950,8 @@ void main() {
       test('fails if unable to check for requested target', () async {
         final Directory pluginDirectory1 = createFakePlugin(
             'plugin', packagesDir,
-            platformSupport: <String, PlatformSupport>{
+            platformSupport: <String, PlatformDetails>{
-              kPlatformMacos: PlatformSupport.inline,
+              kPlatformMacos: const PlatformDetails(PlatformSupport.inline),
             });
 
         final Directory pluginExampleDirectory =
@@ -1007,10 +1007,10 @@ void main() {
             'example/android/gradlew',
             'android/src/test/example_test.java',
           ],
-          platformSupport: <String, PlatformSupport>{
+          platformSupport: <String, PlatformDetails>{
-            kPlatformAndroid: PlatformSupport.inline,
+            kPlatformAndroid: const PlatformDetails(PlatformSupport.inline),
-            kPlatformIos: PlatformSupport.inline,
+            kPlatformIos: const PlatformDetails(PlatformSupport.inline),
-            kPlatformMacos: PlatformSupport.inline,
+            kPlatformMacos: const PlatformDetails(PlatformSupport.inline),
           },
         );
 
@@ -1077,8 +1077,8 @@ void main() {
       test('runs only macOS for a macOS plugin', () async {
         final Directory pluginDirectory1 = createFakePlugin(
             'plugin', packagesDir,
-            platformSupport: <String, PlatformSupport>{
+            platformSupport: <String, PlatformDetails>{
-              kPlatformMacos: PlatformSupport.inline,
+              kPlatformMacos: const PlatformDetails(PlatformSupport.inline),
             });
 
         final Directory pluginExampleDirectory =
@@ -1121,8 +1121,8 @@ void main() {
 
       test('runs only iOS for a iOS plugin', () async {
         final Directory pluginDirectory = createFakePlugin(
-            'plugin', packagesDir, platformSupport: <String, PlatformSupport>{
+            'plugin', packagesDir, platformSupport: <String, PlatformDetails>{
-          kPlatformIos: PlatformSupport.inline
+          kPlatformIos: const PlatformDetails(PlatformSupport.inline)
         });
 
         final Directory pluginExampleDirectory =
@@ -1193,9 +1193,9 @@ void main() {
         final Directory pluginDir = createFakePlugin(
           'plugin',
           packagesDir,
-          platformSupport: <String, PlatformSupport>{
+          platformSupport: <String, PlatformDetails>{
-            kPlatformAndroid: PlatformSupport.inline,
+            kPlatformAndroid: const PlatformDetails(PlatformSupport.inline),
-            kPlatformIos: PlatformSupport.inline,
+            kPlatformIos: const PlatformDetails(PlatformSupport.inline),
           },
           extraFiles: <String>[
             'example/android/gradlew',
@@ -1244,9 +1244,9 @@ void main() {
         final Directory pluginDir = createFakePlugin(
           'plugin',
           packagesDir,
-          platformSupport: <String, PlatformSupport>{
+          platformSupport: <String, PlatformDetails>{
-            kPlatformAndroid: PlatformSupport.inline,
+            kPlatformAndroid: const PlatformDetails(PlatformSupport.inline),
-            kPlatformIos: PlatformSupport.inline,
+            kPlatformIos: const PlatformDetails(PlatformSupport.inline),
           },
           extraFiles: <String>[
             'example/android/gradlew',

script/tool/test/test_command_test.dart

@@ -180,8 +180,8 @@ void main() {
         'plugin',
         packagesDir,
         extraFiles: <String>['test/empty_test.dart'],
-        platformSupport: <String, PlatformSupport>{
+        platformSupport: <String, PlatformDetails>{
-          kPlatformWeb: PlatformSupport.inline,
+          kPlatformWeb: const PlatformDetails(PlatformSupport.inline),
         },
       );
 

script/tool/test/util.dart

@@ -41,6 +41,21 @@ Directory createPackagesDirectory(
   return packagesDir;
 }
 
+/// Details for platform support in a plugin.
+@immutable
+class PlatformDetails {
+  const PlatformDetails(
+    this.type, {
+    this.variants = const <String>[],
+  });
+
+  /// The type of support for the platform.
+  final PlatformSupport type;
+
+  /// Any 'supportVariants' to list in the pubspec.
+  final List<String> variants;
+}
+
 /// Creates a plugin package with the given [name] in [packagesDirectory].
 ///
 /// [platformSupport] is a map of platform string to the support details for
@@ -54,8 +69,8 @@ Directory createFakePlugin(
   Directory parentDirectory, {
   List<String> examples = const <String>['example'],
   List<String> extraFiles = const <String>[],
-  Map<String, PlatformSupport> platformSupport =
+  Map<String, PlatformDetails> platformSupport =
-      const <String, PlatformSupport>{},
+      const <String, PlatformDetails>{},
   String? version = '0.0.1',
 }) {
   final Directory pluginDirectory = createFakePackage(name, parentDirectory,
@@ -143,8 +158,8 @@ void createFakePubspec(
   String name = 'fake_package',
   bool isFlutter = true,
   bool isPlugin = false,
-  Map<String, PlatformSupport> platformSupport =
+  Map<String, PlatformDetails> platformSupport =
-      const <String, PlatformSupport>{},
+      const <String, PlatformDetails>{},
   String publishTo = 'http://no_pub_server.com',
   String? version,
 }) {
@@ -160,12 +175,11 @@ flutter:
   plugin:
     platforms:
 ''';
-      for (final MapEntry<String, PlatformSupport> platform
+      for (final MapEntry<String, PlatformDetails> platform
           in platformSupport.entries) {
         yaml += _pluginPlatformSection(platform.key, platform.value, name);
       }
     }
-
     yaml += '''
 dependencies:
   flutter:
@@ -186,50 +200,73 @@ publish_to: $publishTo # Hardcoded safeguard to prevent this from somehow being
 }
 
 String _pluginPlatformSection(
-    String platform, PlatformSupport type, String packageName) {
+    String platform, PlatformDetails support, String packageName) {
-  if (type == PlatformSupport.federated) {
+  String entry = '';
-    return '''
+  // Build the main plugin entry.
+  if (support.type == PlatformSupport.federated) {
+    entry = '''
       $platform:
         default_package: ${packageName}_$platform
 ''';
-  }
+  } else {
     switch (platform) {
       case kPlatformAndroid:
-      return '''
+        entry = '''
       android:
         package: io.flutter.plugins.fake
         pluginClass: FakePlugin
 ''';
+        break;
       case kPlatformIos:
-      return '''
+        entry = '''
       ios:
         pluginClass: FLTFakePlugin
 ''';
+        break;
       case kPlatformLinux:
-      return '''
+        entry = '''
       linux:
         pluginClass: FakePlugin
 ''';
+        break;
       case kPlatformMacos:
-      return '''
+        entry = '''
       macos:
         pluginClass: FakePlugin
 ''';
+        break;
       case kPlatformWeb:
-      return '''
+        entry = '''
       web:
         pluginClass: FakePlugin
         fileName: ${packageName}_web.dart
 ''';
+        break;
       case kPlatformWindows:
-      return '''
+        entry = '''
       windows:
         pluginClass: FakePlugin
 ''';
+        break;
       default:
-      assert(false);
+        assert(false, 'Unrecognized platform: $platform');
-      return '';
+        break;
     }
+  }
+
+  // Add any variants.
+  if (support.variants.isNotEmpty) {
+    entry += '''
+        supportedVariants:
+''';
+    for (final String variant in support.variants) {
+      entry += '''
+          - $variant
+''';
+    }
+  }
+
+  return entry;
 }
 
 typedef _ErrorHandler = void Function(Error error);

script/tool/test/xcode_analyze_command_test.dart

@@ -57,8 +57,8 @@ void main() {
     group('iOS', () {
       test('skip if iOS is not supported', () async {
         createFakePlugin('plugin', packagesDir,
-            platformSupport: <String, PlatformSupport>{
+            platformSupport: <String, PlatformDetails>{
-              kPlatformMacos: PlatformSupport.inline,
+              kPlatformMacos: const PlatformDetails(PlatformSupport.inline),
             });
 
         final List<String> output =
@@ -70,8 +70,8 @@ void main() {
 
       test('skip if iOS is implemented in a federated package', () async {
         createFakePlugin('plugin', packagesDir,
-            platformSupport: <String, PlatformSupport>{
+            platformSupport: <String, PlatformDetails>{
-              kPlatformIos: PlatformSupport.federated
+              kPlatformIos: const PlatformDetails(PlatformSupport.federated)
             });
 
         final List<String> output =
@@ -83,8 +83,8 @@ void main() {
 
       test('runs for iOS plugin', () async {
         final Directory pluginDirectory = createFakePlugin(
-            'plugin', packagesDir, platformSupport: <String, PlatformSupport>{
+            'plugin', packagesDir, platformSupport: <String, PlatformDetails>{
-          kPlatformIos: PlatformSupport.inline
+          kPlatformIos: const PlatformDetails(PlatformSupport.inline)
         });
 
         final Directory pluginExampleDirectory =
@@ -126,8 +126,8 @@ void main() {
 
       test('fails if xcrun fails', () async {
         createFakePlugin('plugin', packagesDir,
-            platformSupport: <String, PlatformSupport>{
+            platformSupport: <String, PlatformDetails>{
-              kPlatformIos: PlatformSupport.inline
+              kPlatformIos: const PlatformDetails(PlatformSupport.inline)
             });
 
         processRunner.mockProcessesForExecutable['xcrun'] = <io.Process>[
@@ -172,8 +172,8 @@ void main() {
 
       test('skip if macOS is implemented in a federated package', () async {
         createFakePlugin('plugin', packagesDir,
-            platformSupport: <String, PlatformSupport>{
+            platformSupport: <String, PlatformDetails>{
-              kPlatformMacos: PlatformSupport.federated,
+              kPlatformMacos: const PlatformDetails(PlatformSupport.federated),
             });
 
         final List<String> output = await runCapturingPrint(
@@ -186,8 +186,8 @@ void main() {
       test('runs for macOS plugin', () async {
         final Directory pluginDirectory1 = createFakePlugin(
             'plugin', packagesDir,
-            platformSupport: <String, PlatformSupport>{
+            platformSupport: <String, PlatformDetails>{
-              kPlatformMacos: PlatformSupport.inline,
+              kPlatformMacos: const PlatformDetails(PlatformSupport.inline),
             });
 
         final Directory pluginExampleDirectory =
@@ -223,8 +223,8 @@ void main() {
 
       test('fails if xcrun fails', () async {
         createFakePlugin('plugin', packagesDir,
-            platformSupport: <String, PlatformSupport>{
+            platformSupport: <String, PlatformDetails>{
-              kPlatformMacos: PlatformSupport.inline,
+              kPlatformMacos: const PlatformDetails(PlatformSupport.inline),
             });
 
         processRunner.mockProcessesForExecutable['xcrun'] = <io.Process>[
@@ -253,9 +253,9 @@ void main() {
       test('runs both iOS and macOS when supported', () async {
         final Directory pluginDirectory1 = createFakePlugin(
             'plugin', packagesDir,
-            platformSupport: <String, PlatformSupport>{
+            platformSupport: <String, PlatformDetails>{
-              kPlatformIos: PlatformSupport.inline,
+              kPlatformIos: const PlatformDetails(PlatformSupport.inline),
-              kPlatformMacos: PlatformSupport.inline,
+              kPlatformMacos: const PlatformDetails(PlatformSupport.inline),
             });
 
         final Directory pluginExampleDirectory =
@@ -313,8 +313,8 @@ void main() {
       test('runs only macOS for a macOS plugin', () async {
         final Directory pluginDirectory1 = createFakePlugin(
             'plugin', packagesDir,
-            platformSupport: <String, PlatformSupport>{
+            platformSupport: <String, PlatformDetails>{
-              kPlatformMacos: PlatformSupport.inline,
+              kPlatformMacos: const PlatformDetails(PlatformSupport.inline),
             });
 
         final Directory pluginExampleDirectory =
@@ -354,8 +354,8 @@ void main() {
 
       test('runs only iOS for a iOS plugin', () async {
         final Directory pluginDirectory = createFakePlugin(
-            'plugin', packagesDir, platformSupport: <String, PlatformSupport>{
+            'plugin', packagesDir, platformSupport: <String, PlatformDetails>{
-          kPlatformIos: PlatformSupport.inline
+          kPlatformIos: const PlatformDetails(PlatformSupport.inline)
         });
 
         final Directory pluginExampleDirectory =