Control flow collections: flutter_tools/ (#147450)

This pull request aims for improved readability, based on issue #146600.

```dart
// before
List<SupportedPlatform> getSupportedPlatforms({bool includeRoot = false}) {
  final List<SupportedPlatform> platforms = includeRoot
      ? <SupportedPlatform>[SupportedPlatform.root]
      : <SupportedPlatform>[];
  if (android.existsSync()) {
    platforms.add(SupportedPlatform.android);
  }
  if (ios.exists) {
    platforms.add(SupportedPlatform.ios);
  }
  if (web.existsSync()) {
    platforms.add(SupportedPlatform.web);
  }
  if (macos.existsSync()) {
    platforms.add(SupportedPlatform.macos);
  }
  if (linux.existsSync()) {
    platforms.add(SupportedPlatform.linux);
  }
  if (windows.existsSync()) {
    platforms.add(SupportedPlatform.windows);
  }
  if (fuchsia.existsSync()) {
    platforms.add(SupportedPlatform.fuchsia);
  }
  return platforms;
}

// after
List<SupportedPlatform> getSupportedPlatforms({bool includeRoot = false}) {
  return <SupportedPlatform>[
    if (includeRoot)          SupportedPlatform.root,
    if (android.existsSync()) SupportedPlatform.android,
    if (ios.exists)           SupportedPlatform.ios,
    if (web.existsSync())     SupportedPlatform.web,
    if (macos.existsSync())   SupportedPlatform.macos,
    if (linux.existsSync())   SupportedPlatform.linux,
    if (windows.existsSync()) SupportedPlatform.windows,
    if (fuchsia.existsSync()) SupportedPlatform.fuchsia,
  ];
}
```

packages/flutter_tools/lib/src/android/android_studio.dart

@@ -384,17 +384,12 @@ class AndroidStudio {
     final String? homeDirPath = globals.fsUtils.homeDirPath;
 
     if (homeDirPath != null && globals.fs.directory(homeDirPath).existsSync()) {
-      final Directory homeDir = globals.fs.directory(homeDirPath);
-
-      final List<Directory> directoriesToSearch = <Directory>[homeDir];
-
       // >=4.1 has new install location at $HOME/.cache/Google
-      final String cacheDirPath =
+      final String cacheDirPath = globals.fs.path.join(homeDirPath, '.cache', 'Google');
-          globals.fs.path.join(homeDirPath, '.cache', 'Google');
+      final List<Directory> directoriesToSearch = <Directory>[
-
+        globals.fs.directory(homeDirPath),
-      if (globals.fs.isDirectorySync(cacheDirPath)) {
+        if (globals.fs.isDirectorySync(cacheDirPath)) globals.fs.directory(cacheDirPath),
-        directoriesToSearch.add(globals.fs.directory(cacheDirPath));
+      ];
-      }
 
       final List<Directory> entities = <Directory>[];
 

packages/flutter_tools/lib/src/android/gradle.dart

@@ -811,14 +811,11 @@ class AndroidGradleBuilder implements AndroidBuilder {
       _logger.printError(result.stderr, wrap: false);
       return const <String>[];
     }
-    final List<String> options = <String>[];
+    return <String>[
-    for (final String line in LineSplitter.split(result.stdout)) {
+      for (final String line in LineSplitter.split(result.stdout))
-      final RegExpMatch? match = _kBuildVariantRegex.firstMatch(line);
+        if (_kBuildVariantRegex.firstMatch(line) case final RegExpMatch match)
-      if (match != null) {
+          match.namedGroup(_kBuildVariantRegexGroupName)!,
-        options.add(match.namedGroup(_kBuildVariantRegexGroupName)!);
+    ];
-      }
-    }
-    return options;
   }
 
   @override

packages/flutter_tools/lib/src/base/analyze_size.dart

@@ -469,18 +469,15 @@ class _SymbolNode {
   }
 
   Map<String, Object?> toJson() {
-    final Map<String, Object?> json = <String, Object?>{
+    final List<Map<String, Object?>> childrenAsJson = <Map<String, Object?>>[
+      for (final _SymbolNode child in children) child.toJson(),
+    ];
+
+    return <String, Object?>{
       'n': name,
       'value': byteSize,
+      if (childrenAsJson.isNotEmpty) 'children': childrenAsJson,
     };
-    final List<Map<String, Object?>> childrenAsJson = <Map<String, Object?>>[];
-    for (final _SymbolNode child in children) {
-      childrenAsJson.add(child.toJson());
-    }
-    if (childrenAsJson.isNotEmpty) {
-      json['children'] = childrenAsJson;
-    }
-    return json;
   }
 }
 

packages/flutter_tools/lib/src/base/deferred_component.dart

@@ -71,14 +71,11 @@ class DeferredComponent {
   /// status, but will result in [loadingUnits] returning an empty set.
   void assignLoadingUnits(List<LoadingUnit> allLoadingUnits) {
     _assigned = true;
-    _loadingUnits = <LoadingUnit>{};
+    _loadingUnits = <LoadingUnit>{
-    for (final String lib in libraries) {
+      for (final String lib in libraries)
-      for (final LoadingUnit loadingUnit in allLoadingUnits) {
+        for (final LoadingUnit loadingUnit in allLoadingUnits)
-        if (loadingUnit.libraries.contains(lib)) {
+          if (loadingUnit.libraries.contains(lib)) loadingUnit,
-          _loadingUnits!.add(loadingUnit);
+    };
-        }
-      }
-    }
   }
 
   /// Provides a human readable string representation of the
@@ -193,21 +190,16 @@ class LoadingUnit {
     } on FormatException catch (e) {
       logger.printError('Loading unit manifest at `${manifestFile.path}` was invalid JSON:\n$e');
     }
-    final List<LoadingUnit> loadingUnits = <LoadingUnit>[];
+    // Set up android source directory
-    // Setup android source directory
+    return <LoadingUnit>[
-    if (manifest != null) {
+      if (manifest?['loadingUnits'] case final List<dynamic> loadingUnits)
-      for (final dynamic loadingUnitMetadata in manifest['loadingUnits'] as List<dynamic>) {
+        for (final Map<String, dynamic> loadingUnitMap in loadingUnits.cast<Map<String, dynamic>>())
-        final Map<String, dynamic> loadingUnitMap = loadingUnitMetadata as Map<String, dynamic>;
+          if (loadingUnitMap['id'] != 1) // skip base unit
-        if (loadingUnitMap['id'] == 1) {
+            LoadingUnit(
-          continue; // Skip base unit
+              id: loadingUnitMap['id'] as int,
-        }
+              path: loadingUnitMap['path'] as String,
-        loadingUnits.add(LoadingUnit(
+              libraries: List<String>.from(loadingUnitMap['libraries'] as List<dynamic>),
-          id: loadingUnitMap['id'] as int,
+            ),
-          path: loadingUnitMap['path'] as String,
+    ];
-          libraries: List<String>.from(loadingUnitMap['libraries'] as List<dynamic>)),
-        );
-      }
-    }
-    return loadingUnits;
   }
 }

packages/flutter_tools/lib/src/base/process.dart

@@ -69,13 +69,10 @@ class _DefaultShutdownHooks implements ShutdownHooks {
     );
     _shutdownHooksRunning = true;
     try {
-      final List<Future<dynamic>> futures = <Future<dynamic>>[];
+      final List<Future<dynamic>> futures = <Future<dynamic>>[
-      for (final ShutdownHook shutdownHook in registeredHooks) {
+        for (final ShutdownHook shutdownHook in registeredHooks)
-        final FutureOr<dynamic> result = shutdownHook();
+          if (shutdownHook() case final Future<dynamic> result) result,
-        if (result is Future<dynamic>) {
+      ];
-          futures.add(result);
-        }
-      }
       await Future.wait<dynamic>(futures);
     } finally {
       _shutdownHooksRunning = false;

packages/flutter_tools/lib/src/build_system/build_system.dart

@@ -182,21 +182,13 @@ abstract class Target {
     List<File> outputs,
     Environment environment,
   ) {
-    final File stamp = _findStampFile(environment);
+    String getPath(File file) => file.path;
-    final List<String> inputPaths = <String>[];
-    for (final File input in inputs) {
-      inputPaths.add(input.path);
-    }
-    final List<String> outputPaths = <String>[];
-    for (final File output in outputs) {
-      outputPaths.add(output.path);
-    }
-    final String? key = buildKey;
     final Map<String, Object> result = <String, Object>{
-      'inputs': inputPaths,
+      'inputs': inputs.map(getPath).toList(),
-      'outputs': outputPaths,
+      'outputs': outputs.map(getPath).toList(),
-      if (key != null) 'buildKey': key,
+      if (buildKey case final String key) 'buildKey': key,
     };
+    final File stamp = _findStampFile(environment);
     if (!stamp.existsSync()) {
       stamp.createSync();
     }

packages/flutter_tools/lib/src/build_system/depfile.dart

@@ -58,20 +58,12 @@ class DepfileService {
   /// The [file] contains a list of newline separated file URIs. The output
   /// file must be manually specified.
   Depfile parseDart2js(File file, File output) {
-    final List<File> inputs = <File>[];
+    final List<File> inputs = <File>[
-    for (final String rawUri in file.readAsLinesSync()) {
+      for (final String rawUri in file.readAsLinesSync())
-      if (rawUri.trim().isEmpty) {
+        if (rawUri.trim().isNotEmpty)
-        continue;
+          if (Uri.tryParse(rawUri) case final Uri fileUri when fileUri.scheme == 'file')
-      }
+            _fileSystem.file(fileUri),
-      final Uri? fileUri = Uri.tryParse(rawUri);
+    ];
-      if (fileUri == null) {
-        continue;
-      }
-      if (fileUri.scheme != 'file') {
-        continue;
-      }
-      inputs.add(_fileSystem.file(fileUri));
-    }
     return Depfile(inputs, <File>[output]);
   }
 

packages/flutter_tools/lib/src/build_system/targets/deferred_components.dart

@@ -37,15 +37,11 @@ class DeferredComponentsGenSnapshotValidatorTarget extends Target {
 
   /// The abis to validate.
   List<String> get _abis {
-    final List<String> abis = <String>[];
+    return <String>[
-    for (final AndroidAotDeferredComponentsBundle target in deferredComponentsDependencies) {
+      for (final AndroidAotDeferredComponentsBundle target in deferredComponentsDependencies)
-      if (deferredComponentsTargets.contains(target.name)) {
+        if (deferredComponentsTargets.contains(target.name))
-        abis.add(
+          getAndroidArchForName(getNameForTargetPlatform(target.dependency.targetPlatform)).archName,
-          getAndroidArchForName(getNameForTargetPlatform(target.dependency.targetPlatform)).archName
+    ];
-        );
-      }
-    }
-    return abis;
   }
 
   @override

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

@@ -112,19 +112,11 @@ abstract class BuildFrameworkCommand extends BuildSubCommand {
   late final FlutterProject project = FlutterProject.current();
 
   Future<List<BuildInfo>> getBuildInfos() async {
-    final List<BuildInfo> buildInfos = <BuildInfo>[];
+    return <BuildInfo>[
-
+      if (boolArg('debug'))   await getBuildInfo(forcedBuildMode: BuildMode.debug),
-    if (boolArg('debug')) {
+      if (boolArg('profile')) await getBuildInfo(forcedBuildMode: BuildMode.profile),
-      buildInfos.add(await getBuildInfo(forcedBuildMode: BuildMode.debug));
+      if (boolArg('release')) await getBuildInfo(forcedBuildMode: BuildMode.release),
-    }
+    ];
-    if (boolArg('profile')) {
-      buildInfos.add(await getBuildInfo(forcedBuildMode: BuildMode.profile));
-    }
-    if (boolArg('release')) {
-      buildInfos.add(await getBuildInfo(forcedBuildMode: BuildMode.release));
-    }
-
-    return buildInfos;
   }
 
   @override

packages/flutter_tools/lib/src/custom_devices/custom_device.dart

@@ -101,14 +101,11 @@ class CustomDeviceLogReader extends DeviceLogReader {
   /// [logLines] as done.
   @override
   Future<void> dispose() async {
-    final List<Future<void>> futures = <Future<void>>[];
+    final List<Future<void>> futures = <Future<void>>[
-
+      for (final StreamSubscription<String> subscription in subscriptions)
-    for (final StreamSubscription<String> subscription in subscriptions) {
+        subscription.cancel(),
-      futures.add(subscription.cancel());
+      logLinesController.close(),
-    }
+    ];
-
-    futures.add(logLinesController.close());
-
     await Future.wait(futures);
   }
 

packages/flutter_tools/lib/src/doctor.dart

@@ -196,42 +196,16 @@ class _DefaultDoctorValidatorsProvider implements DoctorValidatorsProvider {
 
   @override
   List<Workflow> get workflows {
-    if (_workflows == null) {
+    return _workflows ??= <Workflow>[
-      _workflows = <Workflow>[];
+      if (globals.iosWorkflow!.appliesToHostPlatform)      globals.iosWorkflow!,
-
+      if (androidWorkflow?.appliesToHostPlatform ?? false) androidWorkflow!,
-      if (globals.iosWorkflow!.appliesToHostPlatform) {
+      if (fuchsiaWorkflow?.appliesToHostPlatform ?? false) fuchsiaWorkflow!,
-        _workflows!.add(globals.iosWorkflow!);
+      if (linuxWorkflow.appliesToHostPlatform)             linuxWorkflow,
-      }
+      if (macOSWorkflow.appliesToHostPlatform)             macOSWorkflow,
-
+      if (windowsWorkflow?.appliesToHostPlatform ?? false) windowsWorkflow!,
-      if (androidWorkflow?.appliesToHostPlatform ?? false) {
+      if (webWorkflow.appliesToHostPlatform)               webWorkflow,
-        _workflows!.add(androidWorkflow!);
+      if (customDeviceWorkflow.appliesToHostPlatform)      customDeviceWorkflow,
-      }
+    ];
-
-      if (fuchsiaWorkflow?.appliesToHostPlatform ?? false) {
-        _workflows!.add(fuchsiaWorkflow!);
-      }
-
-      if (linuxWorkflow.appliesToHostPlatform) {
-        _workflows!.add(linuxWorkflow);
-      }
-
-      if (macOSWorkflow.appliesToHostPlatform) {
-        _workflows!.add(macOSWorkflow);
-      }
-
-      if (windowsWorkflow?.appliesToHostPlatform ?? false) {
-        _workflows!.add(windowsWorkflow!);
-      }
-
-      if (webWorkflow.appliesToHostPlatform) {
-        _workflows!.add(webWorkflow);
-      }
-
-      if (customDeviceWorkflow.appliesToHostPlatform) {
-        _workflows!.add(customDeviceWorkflow);
-      }
-    }
-    return _workflows!;
   }
 }
 

packages/flutter_tools/lib/src/flutter_plugins.dart

@@ -316,14 +316,11 @@ public final class GeneratedPluginRegistrant {
 ''';
 
 List<Map<String, Object?>> _extractPlatformMaps(List<Plugin> plugins, String type) {
-  final List<Map<String, Object?>> pluginConfigs = <Map<String, Object?>>[];
+  return <Map<String, Object?>>[
-  for (final Plugin p in plugins) {
+    for (final Plugin plugin in plugins)
-    final PluginPlatform? platformPlugin = p.platforms[type];
+      if (plugin.platforms[type] case final PluginPlatform platformPlugin)
-    if (platformPlugin != null) {
+        platformPlugin.toMap(),
-      pluginConfigs.add(platformPlugin.toMap());
+  ];
-    }
-  }
-  return pluginConfigs;
 }
 
 Future<void> _writeAndroidPluginRegistrant(FlutterProject project, List<Plugin> plugins) async {

packages/flutter_tools/lib/src/fuchsia/fuchsia_device.dart

@@ -188,15 +188,10 @@ class FuchsiaDevices extends PollingDeviceDiscovery {
     if (text == null || text.isEmpty) {
       return <Device>[];
     }
-    final List<FuchsiaDevice> devices = <FuchsiaDevice>[];
+    return <FuchsiaDevice>[
-    for (final String line in text) {
+      for (final String line in text)
-      final FuchsiaDevice? device = await _parseDevice(line);
+        if (await _parseDevice(line) case final FuchsiaDevice device) device,
-      if (device == null) {
+    ];
-        continue;
-      }
-      devices.add(device);
-    }
-    return devices;
   }
 
   @override

packages/flutter_tools/lib/src/ios/core_devices.dart

@@ -117,15 +117,12 @@ class IOSCoreDeviceControl {
   Future<List<IOSCoreDevice>> getCoreDevices({
     Duration timeout = const Duration(seconds: _minimumTimeoutInSeconds),
   }) async {
-    final List<IOSCoreDevice> devices = <IOSCoreDevice>[];
-
     final List<Object?> devicesSection = await _listCoreDevices(timeout: timeout);
-    for (final Object? deviceObject in devicesSection) {
+    return <IOSCoreDevice>[
-      if (deviceObject is Map<String, Object?>) {
+      for (final Object? deviceObject in devicesSection)
-        devices.add(IOSCoreDevice.fromBetaJson(deviceObject, logger: _logger));
+        if (deviceObject is Map<String, Object?>)
-      }
+          IOSCoreDevice.fromBetaJson(deviceObject, logger: _logger),
-    }
+    ];
-    return devices;
   }
 
   /// Executes `devicectl` command to get list of apps installed on the device.
@@ -192,15 +189,12 @@ class IOSCoreDeviceControl {
     required String deviceId,
     String? bundleId,
   }) async {
-    final List<IOSCoreDeviceInstalledApp> apps = <IOSCoreDeviceInstalledApp>[];
-
     final List<Object?> appsData = await _listInstalledApps(deviceId: deviceId, bundleId: bundleId);
-    for (final Object? appObject in appsData) {
+    return <IOSCoreDeviceInstalledApp>[
-      if (appObject is Map<String, Object?>) {
+      for (final Object? appObject in appsData)
-        apps.add(IOSCoreDeviceInstalledApp.fromBetaJson(appObject));
+        if (appObject is Map<String, Object?>)
-      }
+          IOSCoreDeviceInstalledApp.fromBetaJson(appObject),
-    }
+    ];
-    return apps;
   }
 
   Future<bool> isAppInstalled({
@@ -401,15 +395,12 @@ class IOSCoreDevice {
     Map<String, Object?> data, {
     required Logger logger,
   }) {
-    final List<_IOSCoreDeviceCapability> capabilitiesList = <_IOSCoreDeviceCapability>[];
+    final List<_IOSCoreDeviceCapability> capabilitiesList = <_IOSCoreDeviceCapability>[
-    if (data['capabilities'] is List<Object?>) {
+      if (data['capabilities'] case final List<Object?> capabilitiesData)
-      final List<Object?> capabilitiesData = data['capabilities']! as List<Object?>;
+        for (final Object? capabilityData in capabilitiesData)
-      for (final Object? capabilityData in capabilitiesData) {
+          if (capabilityData != null && capabilityData is Map<String, Object?>)
-        if (capabilityData != null && capabilityData is Map<String, Object?>) {
+            _IOSCoreDeviceCapability.fromBetaJson(capabilityData),
-          capabilitiesList.add(_IOSCoreDeviceCapability.fromBetaJson(capabilityData));
+    ];
-        }
-      }
-    }
 
     _IOSCoreDeviceConnectionProperties? connectionProperties;
     if (data['connectionProperties'] is Map<String, Object?>) {
@@ -713,20 +704,17 @@ class _IOSCoreDeviceHardwareProperties {
     required Logger logger,
   }) {
     _IOSCoreDeviceCPUType? cpuType;
-    if (data['cpuType'] is Map<String, Object?>) {
+    if (data['cpuType'] case final Map<String, Object?> betaJson) {
-      cpuType = _IOSCoreDeviceCPUType.fromBetaJson(data['cpuType']! as Map<String, Object?>);
+      cpuType = _IOSCoreDeviceCPUType.fromBetaJson(betaJson);
     }
 
     List<_IOSCoreDeviceCPUType>? supportedCPUTypes;
-    if (data['supportedCPUTypes'] is List<Object?>) {
+    if (data['supportedCPUTypes'] case final List<Object?> values) {
-      final List<Object?> values = data['supportedCPUTypes']! as List<Object?>;
+      supportedCPUTypes = <_IOSCoreDeviceCPUType>[
-      final List<_IOSCoreDeviceCPUType> cpuTypes = <_IOSCoreDeviceCPUType>[];
+        for (final Object? cpuTypeData in values)
-      for (final Object? cpuTypeData in values) {
+          if (cpuTypeData is Map<String, Object?>)
-        if (cpuTypeData is Map<String, Object?>) {
+            _IOSCoreDeviceCPUType.fromBetaJson(cpuTypeData),
-          cpuTypes.add(_IOSCoreDeviceCPUType.fromBetaJson(cpuTypeData));
+      ];
-        }
-      }
-      supportedCPUTypes = cpuTypes;
     }
 
     List<int>? supportedDeviceFamilies;

packages/flutter_tools/lib/src/ios/devices.dart

@@ -782,15 +782,12 @@ class IOSDevice extends Device {
 
     final List<Future<Uri?>> discoveryOptions = <Future<Uri?>>[
       vmUrlFromMDns,
+      // vmServiceDiscovery uses device logs (`idevicesyslog`), which doesn't work
+      // on wireless devices.
+      if (vmServiceDiscovery != null && !isWirelesslyConnected)
+        vmServiceDiscovery.uri,
     ];
 
-    // vmServiceDiscovery uses device logs (`idevicesyslog`), which doesn't work
-    // on wireless devices.
-    if (vmServiceDiscovery != null && !isWirelesslyConnected) {
-      final Future<Uri?> vmUrlFromLogs = vmServiceDiscovery.uri;
-      discoveryOptions.add(vmUrlFromLogs);
-    }
-
     Uri? localUri = await Future.any(
       <Future<Uri?>>[...discoveryOptions, cancelCompleter.future],
     );

packages/flutter_tools/lib/src/ios/simulators.dart

@@ -183,20 +183,14 @@ class SimControl {
 
   /// Returns all the connected simulator devices.
   Future<List<BootedSimDevice>> getConnectedDevices() async {
-    final List<BootedSimDevice> devices = <BootedSimDevice>[];
-
     final Map<String, Object?> devicesSection = await _listBootedDevices();
 
-    for (final String deviceCategory in devicesSection.keys) {
+    return <BootedSimDevice>[
-      final Object? devicesData = devicesSection[deviceCategory];
+      for (final String deviceCategory in devicesSection.keys)
-      if (devicesData != null && devicesData is List<Object?>) {
+        if (devicesSection[deviceCategory] case final List<Object?> devicesData)
-        for (final Map<String, Object?> data in devicesData.map<Map<String, Object?>?>(castStringKeyedMap).whereType<Map<String, Object?>>()) {
+          for (final Object? data in devicesData.map<Map<String, Object?>?>(castStringKeyedMap))
-          devices.add(BootedSimDevice(deviceCategory, data));
+            if (data is Map<String, Object?>) BootedSimDevice(deviceCategory, data),
-        }
+    ];
-      }
-    }
-
-    return devices;
   }
 
   Future<bool> isInstalled(String deviceId, String appId) {

packages/flutter_tools/lib/src/plugins.dart

@@ -298,38 +298,29 @@ class Plugin {
     if (yaml == null) {
       return <String>['Invalid "platforms" specification.'];
     }
-    final List<String> errors = <String>[];
+    return <String>[
-    if (isInvalid(AndroidPlugin.kConfigKey, AndroidPlugin.validate)) {
+      if (isInvalid(AndroidPlugin.kConfigKey, AndroidPlugin.validate))
-      errors.add('Invalid "android" plugin specification.');
+        'Invalid "android" plugin specification.',
-    }
+      if (isInvalid(IOSPlugin.kConfigKey, IOSPlugin.validate))
-    if (isInvalid(IOSPlugin.kConfigKey, IOSPlugin.validate)) {
+        'Invalid "ios" plugin specification.',
-      errors.add('Invalid "ios" plugin specification.');
+      if (isInvalid(LinuxPlugin.kConfigKey, LinuxPlugin.validate))
-    }
+        'Invalid "linux" plugin specification.',
-    if (isInvalid(LinuxPlugin.kConfigKey, LinuxPlugin.validate)) {
+      if (isInvalid(MacOSPlugin.kConfigKey, MacOSPlugin.validate))
-      errors.add('Invalid "linux" plugin specification.');
+        'Invalid "macos" plugin specification.',
-    }
+      if (isInvalid(WindowsPlugin.kConfigKey, WindowsPlugin.validate))
-    if (isInvalid(MacOSPlugin.kConfigKey, MacOSPlugin.validate)) {
+        'Invalid "windows" plugin specification.',
-      errors.add('Invalid "macos" plugin specification.');
+    ];
-    }
-    if (isInvalid(WindowsPlugin.kConfigKey, WindowsPlugin.validate)) {
-      errors.add('Invalid "windows" plugin specification.');
-    }
-    return errors;
   }
 
   static List<String> _validateLegacyYaml(YamlMap yaml) {
-    final List<String> errors = <String>[];
+    return <String>[
-
+      if (yaml['androidPackage'] is! String?)
-    if (yaml['androidPackage'] != null && yaml['androidPackage'] is! String) {
+        'The "androidPackage" must either be null or a string.',
-      errors.add('The "androidPackage" must either be null or a string.');
+      if (yaml['iosPrefix'] is! String?)
-    }
+        'The "iosPrefix" must either be null or a string.',
-    if (yaml['iosPrefix'] != null && yaml['iosPrefix'] is! String) {
+      if (yaml['pluginClass'] is! String?)
-      errors.add('The "iosPrefix" must either be null or a string.');
+        'The "pluginClass" must either be null or a string.',
-    }
+    ];
-    if (yaml['pluginClass'] != null && yaml['pluginClass'] is! String) {
-      errors.add('The "pluginClass" must either be null or a string..');
-    }
-    return errors;
   }
 
   static bool _supportsPlatform(YamlMap platformsYaml, String platformKey) {

packages/flutter_tools/lib/src/project.dart

@@ -288,29 +288,16 @@ class FlutterProject {
 
   /// Returns a list of platform names that are supported by the project.
   List<SupportedPlatform> getSupportedPlatforms({bool includeRoot = false}) {
-    final List<SupportedPlatform> platforms = includeRoot ? <SupportedPlatform>[SupportedPlatform.root] : <SupportedPlatform>[];
+    return <SupportedPlatform>[
-    if (android.existsSync()) {
+      if (includeRoot)          SupportedPlatform.root,
-      platforms.add(SupportedPlatform.android);
+      if (android.existsSync()) SupportedPlatform.android,
-    }
+      if (ios.exists)           SupportedPlatform.ios,
-    if (ios.exists) {
+      if (web.existsSync())     SupportedPlatform.web,
-      platforms.add(SupportedPlatform.ios);
+      if (macos.existsSync())   SupportedPlatform.macos,
-    }
+      if (linux.existsSync())   SupportedPlatform.linux,
-    if (web.existsSync()) {
+      if (windows.existsSync()) SupportedPlatform.windows,
-      platforms.add(SupportedPlatform.web);
+      if (fuchsia.existsSync()) SupportedPlatform.fuchsia,
-    }
+    ];
-    if (macos.existsSync()) {
-      platforms.add(SupportedPlatform.macos);
-    }
-    if (linux.existsSync()) {
-      platforms.add(SupportedPlatform.linux);
-    }
-    if (windows.existsSync()) {
-      platforms.add(SupportedPlatform.windows);
-    }
-    if (fuchsia.existsSync()) {
-      platforms.add(SupportedPlatform.fuchsia);
-    }
-    return platforms;
   }
 
   /// The directory that will contain the example if an example exists.

packages/flutter_tools/lib/src/project_validator.dart

@@ -59,137 +59,53 @@ class VariableDumpMachineProjectValidator extends MachineProjectValidator {
 
   @override
   Future<List<ProjectValidatorResult>> start(FlutterProject project) async {
-    final List<ProjectValidatorResult> result = <ProjectValidatorResult>[];
-
-    result.add(ProjectValidatorResult(
-      name: 'FlutterProject.directory',
-      value: _toJsonValue(project.directory.absolute.path),
-      status: StatusProjectValidator.info,
-    ));
-    result.add(ProjectValidatorResult(
-      name: 'FlutterProject.metadataFile',
-      value: _toJsonValue(project.metadataFile.absolute.path),
-      status: StatusProjectValidator.info,
-    ));
-    result.add(ProjectValidatorResult(
-      name: 'FlutterProject.android.exists',
-      value: _toJsonValue(project.android.existsSync()),
-      status: StatusProjectValidator.info,
-    ));
-    result.add(ProjectValidatorResult(
-      name: 'FlutterProject.ios.exists',
-      value: _toJsonValue(project.ios.exists),
-      status: StatusProjectValidator.info,
-    ));
-    result.add(ProjectValidatorResult(
-      name: 'FlutterProject.web.exists',
-      value: _toJsonValue(project.web.existsSync()),
-      status: StatusProjectValidator.info,
-    ));
-    result.add(ProjectValidatorResult(
-      name: 'FlutterProject.macos.exists',
-      value: _toJsonValue(project.macos.existsSync()),
-      status: StatusProjectValidator.info,
-    ));
-    result.add(ProjectValidatorResult(
-      name: 'FlutterProject.linux.exists',
-      value: _toJsonValue(project.linux.existsSync()),
-      status: StatusProjectValidator.info,
-    ));
-    result.add(ProjectValidatorResult(
-      name: 'FlutterProject.windows.exists',
-      value: _toJsonValue(project.windows.existsSync()),
-      status: StatusProjectValidator.info,
-    ));
-    result.add(ProjectValidatorResult(
-      name: 'FlutterProject.fuchsia.exists',
-      value: _toJsonValue(project.fuchsia.existsSync()),
-      status: StatusProjectValidator.info,
-    ));
-
-    result.add(ProjectValidatorResult(
-      name: 'FlutterProject.android.isKotlin',
-      value: _toJsonValue(project.android.isKotlin),
-      status: StatusProjectValidator.info,
-    ));
-    result.add(ProjectValidatorResult(
-      name: 'FlutterProject.ios.isSwift',
-      value: _toJsonValue(project.ios.isSwift),
-      status: StatusProjectValidator.info,
-    ));
-
-    result.add(ProjectValidatorResult(
-      name: 'FlutterProject.isModule',
-      value: _toJsonValue(project.isModule),
-      status: StatusProjectValidator.info,
-    ));
-    result.add(ProjectValidatorResult(
-      name: 'FlutterProject.isPlugin',
-      value: _toJsonValue(project.isPlugin),
-      status: StatusProjectValidator.info,
-    ));
-
-    result.add(ProjectValidatorResult(
-      name: 'FlutterProject.manifest.appname',
-      value: _toJsonValue(project.manifest.appName),
-      status: StatusProjectValidator.info,
-    ));
-
-    // FlutterVersion
     final FlutterVersion version = FlutterVersion(
       flutterRoot: Cache.flutterRoot!,
       fs: fileSystem,
     );
-    result.add(ProjectValidatorResult(
+    final Map<String, Object?> result = <String, Object?>{
-      name: 'FlutterVersion.frameworkRevision',
+      'FlutterProject.directory':         project.directory.absolute.path,
-      value: _toJsonValue(version.frameworkRevision),
+      'FlutterProject.metadataFile':      project.metadataFile.absolute.path,
-      status: StatusProjectValidator.info,
+      'FlutterProject.android.exists':    project.android.existsSync(),
-    ));
+      'FlutterProject.ios.exists':        project.ios.exists,
+      'FlutterProject.web.exists':        project.web.existsSync(),
+      'FlutterProject.macos.exists':      project.macos.existsSync(),
+      'FlutterProject.linux.exists':      project.linux.existsSync(),
+      'FlutterProject.windows.exists':    project.windows.existsSync(),
+      'FlutterProject.fuchsia.exists':    project.fuchsia.existsSync(),
 
-    // Platform
+      'FlutterProject.android.isKotlin':  project.android.isKotlin,
-    result.add(ProjectValidatorResult(
+      'FlutterProject.ios.isSwift':       project.ios.isSwift,
-      name: 'Platform.operatingSystem',
-      value: _toJsonValue(platform.operatingSystem),
-      status: StatusProjectValidator.info,
-    ));
-    result.add(ProjectValidatorResult(
-      name: 'Platform.isAndroid',
-      value: _toJsonValue(platform.isAndroid),
-      status: StatusProjectValidator.info,
-    ));
-    result.add(ProjectValidatorResult(
-      name: 'Platform.isIOS',
-      value: _toJsonValue(platform.isIOS),
-      status: StatusProjectValidator.info,
-    ));
-    result.add(ProjectValidatorResult(
-      name: 'Platform.isWindows',
-      value: _toJsonValue(platform.isWindows),
-      status: StatusProjectValidator.info,
-    ));
-    result.add(ProjectValidatorResult(
-      name: 'Platform.isMacOS',
-      value: _toJsonValue(platform.isMacOS),
-      status: StatusProjectValidator.info,
-    ));
-    result.add(ProjectValidatorResult(
-      name: 'Platform.isFuchsia',
-      value: _toJsonValue(platform.isFuchsia),
-      status: StatusProjectValidator.info,
-    ));
-    result.add(ProjectValidatorResult(
-      name: 'Platform.pathSeparator',
-      value: _toJsonValue(platform.pathSeparator),
-      status: StatusProjectValidator.info,
-    ));
 
-    // Cache
+      'FlutterProject.isModule':          project.isModule,
-    result.add(ProjectValidatorResult(
+      'FlutterProject.isPlugin':          project.isPlugin,
-      name: 'Cache.flutterRoot',
+
-      value: _toJsonValue(Cache.flutterRoot),
+      'FlutterProject.manifest.appname':  project.manifest.appName,
-      status: StatusProjectValidator.info,
+
-    ));
+      // FlutterVersion
-    return result;
+      'FlutterVersion.frameworkRevision': version.frameworkRevision,
+
+      // Platform
+      'Platform.operatingSystem':         platform.operatingSystem,
+      'Platform.isAndroid':               platform.isAndroid,
+      'Platform.isIOS':                   platform.isIOS,
+      'Platform.isWindows':               platform.isWindows,
+      'Platform.isMacOS':                 platform.isMacOS,
+      'Platform.isFuchsia':               platform.isFuchsia,
+      'Platform.pathSeparator':           platform.pathSeparator,
+
+      // Cache
+      'Cache.flutterRoot':                Cache.flutterRoot,
+    };
+
+    return <ProjectValidatorResult>[
+      for (final String key in result.keys)
+        ProjectValidatorResult(
+          name: key,
+          value: _toJsonValue(result[key]),
+          status: StatusProjectValidator.info,
+        ),
+    ];
   }
 
   @override

packages/flutter_tools/lib/src/proxy_validator.dart

@@ -62,19 +62,14 @@ class ProxyValidator extends DoctorValidator {
   }
 
   Future<List<String>> _getLoopbackAddresses() async {
-    final List<String> loopBackAddresses = <String>['localhost'];
-
     final List<NetworkInterface> networkInterfaces =
       await listNetworkInterfaces(includeLinkLocal: true, includeLoopback: true);
 
-    for (final NetworkInterface networkInterface in networkInterfaces) {
+    return <String>[
-      for (final InternetAddress internetAddress in networkInterface.addresses) {
+      'localhost',
-        if (internetAddress.isLoopback) {
+      for (final NetworkInterface networkInterface in networkInterfaces)
-          loopBackAddresses.add(internetAddress.address);
+        for (final InternetAddress internetAddress in networkInterface.addresses)
-        }
+          if (internetAddress.isLoopback) internetAddress.address,
-      }
+    ];
-    }
-
-    return loopBackAddresses;
   }
 }

packages/flutter_tools/lib/src/resident_runner.dart

@@ -1452,17 +1452,12 @@ abstract class ResidentRunner extends ResidentHandlers {
 
   Future<void> enableObservatory() async {
     assert(debuggingOptions.serveObservatory);
-    final List<Future<vm_service.Response?>> serveObservatoryRequests = <Future<vm_service.Response?>>[];
+    final List<Future<vm_service.Response?>> serveObservatoryRequests = <Future<vm_service.Response?>>[
-    for (final FlutterDevice? device in flutterDevices) {
+      for (final FlutterDevice? device in flutterDevices)
-      if (device == null) {
+        if (device != null)
-        continue;
+          // Notify the VM service if the user wants Observatory to be served.
-      }
+          device.vmService?.callMethodWrapper('_serveObservatory') ?? Future<vm_service.Response?>.value(),
-      // Notify the VM service if the user wants Observatory to be served.
+    ];
-      serveObservatoryRequests.add(
-        device.vmService?.callMethodWrapper('_serveObservatory') ??
-          Future<vm_service.Response?>.value(),
-      );
-    }
     try {
       await Future.wait(serveObservatoryRequests);
     } on vm_service.RPCError catch (e) {

packages/flutter_tools/lib/src/test/test_time_recorder.dart

@@ -35,11 +35,7 @@ class TestTimeRecorder {
 
   @visibleForTesting
   List<String> getPrintAsListForTesting() {
-    final List<String> result = <String>[];
+    return TestTimePhases.values.map(_getPrintStringForPhase).toList();
-    for (final TestTimePhases phase in TestTimePhases.values) {
-      result.add(_getPrintStringForPhase(phase));
-    }
-    return result;
   }
 
   @visibleForTesting

packages/flutter_tools/lib/src/vmservice.dart

@@ -993,14 +993,11 @@ class FlutterVmService {
       throw VmServiceDisappearedException();
     }
 
-    final List<vm_service.IsolateRef> refs = <vm_service.IsolateRef>[];
+    return <vm_service.IsolateRef>[
-    for (final FlutterView flutterView in flutterViews) {
+      for (final FlutterView flutterView in flutterViews)
-      final vm_service.IsolateRef? uiIsolate = flutterView.uiIsolate;
+        if (flutterView.uiIsolate case final vm_service.IsolateRef uiIsolate)
-      if (uiIsolate != null) {
+          uiIsolate,
-        refs.add(uiIsolate);
+    ];
-      }
-    }
-    return refs;
   }
 
   /// Attempt to retrieve the isolate with id [isolateId], or `null` if it has

packages/flutter_tools/lib/src/windows/application_package.dart

@@ -52,12 +52,10 @@ abstract class WindowsApp extends ApplicationPackage {
       globals.printError('Invalid prebuilt Windows app. Unable to extract from archive.');
       return null;
     }
-    final List<FileSystemEntity> exeFilesFound = <FileSystemEntity>[];
+    final List<FileSystemEntity> exeFilesFound = <FileSystemEntity>[
-    for (final FileSystemEntity file in tempDir.listSync()) {
+      for (final FileSystemEntity file in tempDir.listSync())
-      if (file.basename.endsWith('.exe')) {
+        if (file.basename.endsWith('.exe')) file,
-        exeFilesFound.add(file);
+    ];
-      }
-    }
 
     if (exeFilesFound.isEmpty) {
       globals.printError('Cannot find .exe files in the zip archive.');

packages/flutter_tools/lib/src/xcode_project.dart

@@ -385,14 +385,11 @@ class IosProject extends XcodeBasedProject {
           )?.cast<String>();
 
           if (domains != null) {
-            final List<String> result = <String>[];
+            return <String>[
-            for (final String domain in domains) {
+              for (final String domain in domains)
-              final RegExpMatch? match = _associatedDomainPattern.firstMatch(domain);
+                if (_associatedDomainPattern.firstMatch(domain) case final RegExpMatch match)
-              if (match != null) {
+                  match.group(1)!,
-                result.add(match.group(1)!);
+            ];
-              }
-            }
-            return result;
           }
         }
       }

packages/flutter_tools/test/commands.shard/hermetic/devices_test.dart

@@ -836,14 +836,12 @@ class _FakeDeviceManager extends DeviceManager {
 
   @override
   Future<List<Device>> getAllDevices({DeviceDiscoveryFilter? filter}) async {
-    final List<Device> devices = <Device>[];
+    final DeviceConnectionInterface? interface = filter?.deviceConnectionInterface;
-    for (final FakeDeviceJsonData deviceJson in fakeDevices) {
+    return <Device>[
-      if (filter?.deviceConnectionInterface == null ||
+      for (final FakeDeviceJsonData deviceJson in fakeDevices)
-          deviceJson.dev.connectionInterface == filter?.deviceConnectionInterface) {
+        if (interface == null || deviceJson.dev.connectionInterface == interface)
-        devices.add(deviceJson.dev);
+          deviceJson.dev,
-      }
+    ];
-    }
-    return devices;
   }
 
   @override