Added warning when not enabled platform is selected (#73205)

packages/flutter_tools/lib/src/commands/create.dart

@@ -300,13 +300,19 @@ class CreateCommand extends CreateBase {
       } else if (_getSupportedPlatformsInPlugin(projectDir).isEmpty){
         _printNoPluginMessage();
       }
-      _printAddPlatformMessage(relativePluginPath);
+
+      final List<String> platformsToWarn = _getPlatformWarningList(requestedPlatforms);
+      if (platformsToWarn.isNotEmpty) {
+        _printWarningDisabledPlatform(platformsToWarn);
+      }
+      _printPluginAddPlatformMessage(relativePluginPath);
     } else  {
       // Tell the user the next steps.
       final FlutterProject project = FlutterProject.fromPath(projectDirPath);
       final FlutterProject app = project.hasExampleApp ? project.example : project;
       final String relativeAppPath = globals.fs.path.normalize(globals.fs.path.relative(app.directory.path));
       final String relativeAppMain = globals.fs.path.join(relativeAppPath, 'lib', 'main.dart');
+      final List<String> requestedPlatforms = _getUserRequestedPlatforms();
 
       // Let them know a summary of the state of their tooling.
       globals.printStatus('''
@@ -322,7 +328,13 @@ To enable null safety, type:
 
 Your $application code is in $relativeAppMain.
 ''');
+      // Show warning if any selected platform is not enabled
+      final List<String> platformsToWarn = _getPlatformWarningList(requestedPlatforms);
+      if (platformsToWarn.isNotEmpty) {
+        _printWarningDisabledPlatform(platformsToWarn);
+      }
     }
+
     return FlutterCommandResult.success();
   }
 
@@ -500,21 +512,64 @@ To edit platform code in an IDE see https://flutter.dev/developing-packages/#edi
 void _printPluginUpdatePubspecMessage(String pluginPath, String platformsString) {
   globals.printStatus('''
 You need to update $pluginPath/pubspec.yaml to support $platformsString.
-
 ''', emphasis: true, color: TerminalColor.red);
 }
 
 void _printNoPluginMessage() {
     globals.printError('''
 You've created a plugin project that doesn't yet support any platforms.
-
 ''');
 }
 
-void _printAddPlatformMessage(String pluginPath) {
+void _printPluginAddPlatformMessage(String pluginPath) {
   globals.printStatus('''
 To add platforms, run `flutter create -t plugin --platforms <platforms> .` under $pluginPath.
 For more information, see https://flutter.dev/go/plugin-platforms.
 
 ''');
 }
+
+// returns a list disabled, but requested platforms
+List<String> _getPlatformWarningList(List<String> requestedPlatforms) {
+  final List<String> platformsToWarn = <String>[
+  if (requestedPlatforms.contains('web') && !featureFlags.isWebEnabled)
+    'web',
+  if (requestedPlatforms.contains('macos') && !featureFlags.isMacOSEnabled)
+    'macos',
+  if (requestedPlatforms.contains('windows') && !featureFlags.isWindowsEnabled)
+    'windows',
+  if (requestedPlatforms.contains('linux') && !featureFlags.isLinuxEnabled)
+    'linux',
+  ];
+
+  return platformsToWarn;
+}
+
+void _printWarningDisabledPlatform(List<String> platforms) {
+  final List<String> desktop = <String>[];
+  final List<String> web = <String>[];
+
+  for (final String platform in platforms) {
+    if (platform == 'web') {
+      web.add(platform);
+    } else if (platform == 'macos' || platform == 'windows' || platform == 'linux') {
+      desktop.add(platform);
+    }
+  }
+
+  if (desktop.isNotEmpty) {
+    final String platforms = desktop.length > 1 ? 'platforms' : 'platform';
+    final String verb = desktop.length > 1 ? 'are' : 'is';
+
+    globals.printStatus('''
+The desktop $platforms: ${desktop.join(', ')} $verb currently not supported on your local environment.
+For more details, see: https://flutter.dev/desktop
+''');
+  }
+  if (web.isNotEmpty) {
+    globals.printStatus('''
+The web is currently not supported on your local environment.
+For more details, see: https://flutter.dev/docs/get-started/web
+''');
+  }
+}

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

@@ -37,6 +37,7 @@ import '../../src/testbed.dart';
 const String _kNoPlatformsMessage = 'You\'ve created a plugin project that doesn\'t yet support any platforms.\n';
 const String frameworkRevision = '12345678';
 const String frameworkChannel = 'omega';
+const String _kDisabledPlatformRequestedMessage = 'currently not supported on your local environment.';
 // TODO(fujino): replace FakePlatform.fromPlatform() with FakePlatform()
 final Generator _kNoColorTerminalPlatform = () => FakePlatform.fromPlatform(const LocalPlatform())..stdoutSupportsAnsi = false;
 final Map<Type, Generator> noColorTerminalOverride = <Type, Generator>{
@@ -2352,6 +2353,74 @@ void main() {
     Logger: () => logger,
   });
 
+  testUsingContext('should show warning when disabled platforms are selected while creating a plugin', () async {
+    Cache.flutterRoot = '../..';
+    when(mockFlutterVersion.frameworkRevision).thenReturn(frameworkRevision);
+    when(mockFlutterVersion.channel).thenReturn(frameworkChannel);
+
+    final CreateCommand command = CreateCommand();
+    final CommandRunner<void> runner = createTestCommandRunner(command);
+
+    await runner.run(<String>['create', '--no-pub', '--template=plugin', '--platforms=android,ios,web,windows,macos,linux', projectDir.path]);
+    await runner.run(<String>['create', '--no-pub', '--template=plugin', projectDir.path]);
+    expect(logger.statusText, contains(_kDisabledPlatformRequestedMessage));
+
+  }, overrides: <Type, Generator>{
+    FeatureFlags: () => TestFeatureFlags(),
+    Logger: () => logger,
+  });
+
+  testUsingContext("shouldn't show warning when only enabled platforms are selected while creating a plugin", () async {
+    Cache.flutterRoot = '../..';
+    when(mockFlutterVersion.frameworkRevision).thenReturn(frameworkRevision);
+    when(mockFlutterVersion.channel).thenReturn(frameworkChannel);
+
+    final CreateCommand command = CreateCommand();
+    final CommandRunner<void> runner = createTestCommandRunner(command);
+
+    await runner.run(<String>['create', '--no-pub', '--template=plugin', '--platforms=android,ios,windows', projectDir.path]);
+    await runner.run(<String>['create', '--no-pub', '--template=plugin', projectDir.path]);
+    expect(logger.statusText, isNot(contains(_kDisabledPlatformRequestedMessage)));
+
+  }, overrides: <Type, Generator>{
+    FeatureFlags: () => TestFeatureFlags(isWindowsEnabled: true),
+    Logger: () => logger,
+  });
+
+  testUsingContext('should show warning when disabled platforms are selected while creating a app', () async {
+    Cache.flutterRoot = '../..';
+    when(mockFlutterVersion.frameworkRevision).thenReturn(frameworkRevision);
+    when(mockFlutterVersion.channel).thenReturn(frameworkChannel);
+
+    final CreateCommand command = CreateCommand();
+    final CommandRunner<void> runner = createTestCommandRunner(command);
+
+    await runner.run(<String>['create', '--no-pub', '--platforms=android,ios,web,windows,macos,linux', projectDir.path]);
+    await runner.run(<String>['create', '--no-pub', projectDir.path]);
+    expect(logger.statusText, contains(_kDisabledPlatformRequestedMessage));
+
+  }, overrides: <Type, Generator>{
+    FeatureFlags: () => TestFeatureFlags(),
+    Logger: () => logger,
+  });
+
+  testUsingContext("shouldn't show warning when only enabled platforms are selected while creating a app", () async {
+    Cache.flutterRoot = '../..';
+    when(mockFlutterVersion.frameworkRevision).thenReturn(frameworkRevision);
+    when(mockFlutterVersion.channel).thenReturn(frameworkChannel);
+
+    final CreateCommand command = CreateCommand();
+    final CommandRunner<void> runner = createTestCommandRunner(command);
+
+    await runner.run(<String>['create', '--no-pub', '--template=plugin', '--platforms=windows', projectDir.path]);
+    await runner.run(<String>['create', '--no-pub', '--template=plugin', projectDir.path]);
+    expect(logger.statusText, isNot(contains(_kDisabledPlatformRequestedMessage)));
+
+  }, overrides: <Type, Generator>{
+    FeatureFlags: () => TestFeatureFlags(isWindowsEnabled: true, isAndroidEnabled: false, isIOSEnabled: false),
+    Logger: () => logger,
+  });
+
   testUsingContext('flutter create prints note about null safety', () async {
     await _createProject(
       projectDir,