Implementing switch expressions in flutter_tools/ (#145632)

This pull request is step 12 in the journey to make this entire repository more readable.

(previous PRs: #139048, #139882, #141591, #142279, #142634, #142793, #143293, #143496, #143634, #143812, #144580)

We're getting close to the end! 😄

packages/flutter_tools/lib/src/build_info.dart

@@ -681,108 +681,66 @@ DarwinArch getIOSArchForName(String arch) {
 }
 
 DarwinArch getDarwinArchForName(String arch) {
-  switch (arch) {
+  return switch (arch) {
-    case 'arm64':
+    'arm64'  => DarwinArch.arm64,
-      return DarwinArch.arm64;
+    'x86_64' => DarwinArch.x86_64,
-    case 'x86_64':
+    _ => throw Exception('Unsupported MacOS arch name "$arch"'),
-      return DarwinArch.x86_64;
+  };
-  }
-  throw Exception('Unsupported MacOS arch name "$arch"');
 }
 
 String getNameForTargetPlatform(TargetPlatform platform, {DarwinArch? darwinArch}) {
-  switch (platform) {
+  return switch (platform) {
-    case TargetPlatform.android_arm:
+    TargetPlatform.ios    when darwinArch != null => 'ios-${darwinArch.name}',
-      return 'android-arm';
+    TargetPlatform.darwin when darwinArch != null => 'darwin-${darwinArch.name}',
-    case TargetPlatform.android_arm64:
+    TargetPlatform.ios            => 'ios',
-      return 'android-arm64';
+    TargetPlatform.darwin         => 'darwin',
-    case TargetPlatform.android_x64:
+    TargetPlatform.android_arm    => 'android-arm',
-      return 'android-x64';
+    TargetPlatform.android_arm64  => 'android-arm64',
-    case TargetPlatform.android_x86:
+    TargetPlatform.android_x64    => 'android-x64',
-      return 'android-x86';
+    TargetPlatform.android_x86    => 'android-x86',
-    case TargetPlatform.ios:
+    TargetPlatform.linux_x64      => 'linux-x64',
-      if (darwinArch != null) {
+    TargetPlatform.linux_arm64    => 'linux-arm64',
-        return 'ios-${darwinArch.name}';
+    TargetPlatform.windows_x64    => 'windows-x64',
-      }
+    TargetPlatform.windows_arm64  => 'windows-arm64',
-      return 'ios';
+    TargetPlatform.fuchsia_arm64  => 'fuchsia-arm64',
-    case TargetPlatform.darwin:
+    TargetPlatform.fuchsia_x64    => 'fuchsia-x64',
-      if (darwinArch != null) {
+    TargetPlatform.tester         => 'flutter-tester',
-        return 'darwin-${darwinArch.name}';
+    TargetPlatform.web_javascript => 'web-javascript',
-      }
+    TargetPlatform.android        => 'android',
-      return 'darwin';
+  };
-    case TargetPlatform.linux_x64:
-      return 'linux-x64';
-    case TargetPlatform.linux_arm64:
-      return 'linux-arm64';
-    case TargetPlatform.windows_x64:
-      return 'windows-x64';
-    case TargetPlatform.windows_arm64:
-      return 'windows-arm64';
-    case TargetPlatform.fuchsia_arm64:
-      return 'fuchsia-arm64';
-    case TargetPlatform.fuchsia_x64:
-      return 'fuchsia-x64';
-    case TargetPlatform.tester:
-      return 'flutter-tester';
-    case TargetPlatform.web_javascript:
-      return 'web-javascript';
-    case TargetPlatform.android:
-      return 'android';
-  }
 }
 
 TargetPlatform getTargetPlatformForName(String platform) {
-  switch (platform) {
+  return switch (platform) {
-    case 'android':
+    'android'       => TargetPlatform.android,
-      return TargetPlatform.android;
+    'android-arm'   => TargetPlatform.android_arm,
-    case 'android-arm':
+    'android-arm64' => TargetPlatform.android_arm64,
-      return TargetPlatform.android_arm;
+    'android-x64'   => TargetPlatform.android_x64,
-    case 'android-arm64':
+    'android-x86'   => TargetPlatform.android_x86,
-      return TargetPlatform.android_arm64;
+    'fuchsia-arm64' => TargetPlatform.fuchsia_arm64,
-    case 'android-x64':
+    'fuchsia-x64'   => TargetPlatform.fuchsia_x64,
-      return TargetPlatform.android_x64;
+    'ios'           => TargetPlatform.ios,
-    case 'android-x86':
-      return TargetPlatform.android_x86;
-    case 'fuchsia-arm64':
-      return TargetPlatform.fuchsia_arm64;
-    case 'fuchsia-x64':
-      return TargetPlatform.fuchsia_x64;
-    case 'ios':
-      return TargetPlatform.ios;
-    case 'darwin':
     // For backward-compatibility and also for Tester, where it must match
     // host platform name (HostPlatform.darwin_x64)
-    case 'darwin-x64':
+    'darwin' || 'darwin-x64' || 'darwin-arm64' => TargetPlatform.darwin,
-    case 'darwin-arm64':
+    'linux-x64'      => TargetPlatform.linux_x64,
-      return TargetPlatform.darwin;
+    'linux-arm64'    => TargetPlatform.linux_arm64,
-    case 'linux-x64':
+    'windows-x64'    => TargetPlatform.windows_x64,
-      return TargetPlatform.linux_x64;
+    'windows-arm64'  => TargetPlatform.windows_arm64,
-   case 'linux-arm64':
+    'web-javascript' => TargetPlatform.web_javascript,
-      return TargetPlatform.linux_arm64;
+    'flutter-tester' => TargetPlatform.tester,
-    case 'windows-x64':
+    _ => throw Exception('Unsupported platform name "$platform"'),
-      return TargetPlatform.windows_x64;
+  };
-    case 'windows-arm64':
-      return TargetPlatform.windows_arm64;
-    case 'web-javascript':
-      return TargetPlatform.web_javascript;
-    case 'flutter-tester':
-      return TargetPlatform.tester;
-  }
-  throw Exception('Unsupported platform name "$platform"');
 }
 
 AndroidArch getAndroidArchForName(String platform) {
-  switch (platform) {
+  return switch (platform) {
-    case 'android-arm':
+    'android-arm'   => AndroidArch.armeabi_v7a,
-      return AndroidArch.armeabi_v7a;
+    'android-arm64' => AndroidArch.arm64_v8a,
-    case 'android-arm64':
+    'android-x64'   => AndroidArch.x86_64,
-      return AndroidArch.arm64_v8a;
+    'android-x86'   => AndroidArch.x86,
-    case 'android-x64':
+    _ => throw Exception('Unsupported Android arch name "$platform"'),
-      return AndroidArch.x86_64;
+  };
-    case 'android-x86':
-      return AndroidArch.x86;
-  }
-  throw Exception('Unsupported Android arch name "$platform"');
 }
 
 HostPlatform getCurrentHostPlatform() {

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

@@ -88,36 +88,26 @@ class SourceVisitor implements ResolvedFiles {
   void visitPattern(String pattern, bool optional) {
     // perform substitution of the environmental values and then
     // of the local values.
-    final List<String> segments = <String>[];
     final List<String> rawParts = pattern.split('/');
     final bool hasWildcard = rawParts.last.contains('*');
     String? wildcardFile;
     if (hasWildcard) {
       wildcardFile = rawParts.removeLast();
     }
+    final List<String> segments = <String>[
+      ...environment.fileSystem.path.split(switch (rawParts.first) {
+        // flutter root will not contain a symbolic link.
+        Environment.kFlutterRootDirectory => environment.flutterRootDir.absolute.path,
+        Environment.kProjectDirectory     => environment.projectDir.resolveSymbolicLinksSync(),
+        Environment.kBuildDirectory       => environment.buildDir.resolveSymbolicLinksSync(),
+        Environment.kCacheDirectory       => environment.cacheDir.resolveSymbolicLinksSync(),
+        Environment.kOutputDirectory      => environment.outputDir.resolveSymbolicLinksSync(),
         // If the pattern does not start with an env variable, then we have nothing
         // to resolve it to, error out.
-    switch (rawParts.first) {
+        _ => throw InvalidPatternException(pattern),
-      case Environment.kProjectDirectory:
+      }),
-        segments.addAll(
+      ...rawParts.skip(1),
-          environment.fileSystem.path.split(environment.projectDir.resolveSymbolicLinksSync()));
+    ];
-      case Environment.kBuildDirectory:
-        segments.addAll(environment.fileSystem.path.split(
-          environment.buildDir.resolveSymbolicLinksSync()));
-      case Environment.kCacheDirectory:
-        segments.addAll(
-          environment.fileSystem.path.split(environment.cacheDir.resolveSymbolicLinksSync()));
-      case Environment.kFlutterRootDirectory:
-        // flutter root will not contain a symbolic link.
-        segments.addAll(
-          environment.fileSystem.path.split(environment.flutterRootDir.absolute.path));
-      case Environment.kOutputDirectory:
-        segments.addAll(
-          environment.fileSystem.path.split(environment.outputDir.resolveSymbolicLinksSync()));
-      default:
-        throw InvalidPatternException(pattern);
-    }
-    rawParts.skip(1).forEach(segments.add);
     final String filePath = environment.fileSystem.path.joinAll(segments);
     if (!hasWildcard) {
       if (optional && !environment.fileSystem.isFileSync(filePath)) {

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

@@ -1229,21 +1229,14 @@ class PubspecHeader extends PubspecLine {
     final List<String> parts = strippedLine.split(':');
     final String sectionName = parts.first;
     final String value = parts.last.trim();
-    switch (sectionName) {
+    return switch (sectionName) {
-      case 'dependencies':
+      'dependencies'         => PubspecHeader(line, Section.dependencies),
-        return PubspecHeader(line, Section.dependencies);
+      'dev_dependencies'     => PubspecHeader(line, Section.devDependencies),
-      case 'dev_dependencies':
+      'dependency_overrides' => PubspecHeader(line, Section.dependencyOverrides),
-        return PubspecHeader(line, Section.devDependencies);
+      'builders'             => PubspecHeader(line, Section.builders),
-      case 'dependency_overrides':
+      'name' || 'version'    => PubspecHeader(line, Section.header, name: sectionName, value: value),
-        return PubspecHeader(line, Section.dependencyOverrides);
+      _                      => PubspecHeader(line, Section.other),
-      case 'builders':
+    };
-        return PubspecHeader(line, Section.builders);
-      case 'name':
-      case 'version':
-        return PubspecHeader(line, Section.header, name: sectionName, value: value);
-      default:
-        return PubspecHeader(line, Section.other);
-    }
   }
 
   /// Returns the input after removing trailing spaces and anything after the

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

@@ -98,19 +98,12 @@ class ValidateProject {
   }
 
   String getStringResult(ProjectValidatorResult result) {
-    final String icon;
+    final String icon = switch (result.status) {
-    switch (result.status) {
+      StatusProjectValidator.warning => '[!]',
-      case StatusProjectValidator.error:
+      StatusProjectValidator.error   => '[✗]',
-        icon = '[✗]';
+      StatusProjectValidator.crash   => '[☠]',
-      case StatusProjectValidator.info:
+      StatusProjectValidator.info || StatusProjectValidator.success => '[✓]',
-      case StatusProjectValidator.success:
+    };
-        icon = '[✓]';
-      case StatusProjectValidator.warning:
-        icon = '[!]';
-      case StatusProjectValidator.crash:
-        icon = '[☠]';
-    }
-
     return '$icon $result';
   }
 }

packages/flutter_tools/lib/src/compile.dart

@@ -31,17 +31,13 @@ class TargetModel {
   /// Throws an exception if passed a value other than 'flutter',
   /// 'flutter_runner', 'vm', or 'dartdevc'.
   factory TargetModel(String rawValue) {
-    switch (rawValue) {
+    return switch (rawValue) {
-      case 'flutter':
+      'flutter'        => flutter,
-        return flutter;
+      'flutter_runner' => flutterRunner,
-      case 'flutter_runner':
+      'vm'             => vm,
-        return flutterRunner;
+      'dartdevc'       => dartdevc,
-      case 'vm':
+      _ => throw Exception('Unexpected target model $rawValue'),
-        return vm;
+    };
-      case 'dartdevc':
-        return dartdevc;
-    }
-    throw Exception('Unexpected target model $rawValue');
   }
 
   const TargetModel._(this._value);

packages/flutter_tools/lib/src/dart/analysis.dart

@@ -242,15 +242,11 @@ class AnalysisError implements Comparable<AnalysisError> {
   String get _separator => _platform.isWindows ? '-' : '•';
 
   String get colorSeverity {
-    switch (writtenError.severityLevel) {
+    return switch (writtenError.severityLevel) {
-      case AnalysisSeverity.error:
+      AnalysisSeverity.error   => _terminal.color(writtenError.severity, TerminalColor.red),
-        return _terminal.color(writtenError.severity, TerminalColor.red);
+      AnalysisSeverity.warning => _terminal.color(writtenError.severity, TerminalColor.yellow),
-      case AnalysisSeverity.warning:
+      AnalysisSeverity.info || AnalysisSeverity.none => writtenError.severity,
-        return _terminal.color(writtenError.severity, TerminalColor.yellow);
+    };
-      case AnalysisSeverity.info:
-      case AnalysisSeverity.none:
-        return writtenError.severity;
-    }
   }
 
   String get type => writtenError.type;

packages/flutter_tools/lib/src/device.dart

@@ -581,23 +581,19 @@ enum DeviceConnectionInterface {
 
 /// Returns the `DeviceConnectionInterface` enum based on its string name.
 DeviceConnectionInterface getDeviceConnectionInterfaceForName(String name) {
-  switch (name) {
+  return switch (name) {
-    case 'attached':
+    'attached' => DeviceConnectionInterface.attached,
-      return DeviceConnectionInterface.attached;
+    'wireless' => DeviceConnectionInterface.wireless,
-    case 'wireless':
+    _ => throw Exception('Unsupported DeviceConnectionInterface name "$name"'),
-      return DeviceConnectionInterface.wireless;
+  };
-  }
-  throw Exception('Unsupported DeviceConnectionInterface name "$name"');
 }
 
 /// Returns a `DeviceConnectionInterface`'s string name.
 String getNameForDeviceConnectionInterface(DeviceConnectionInterface connectionInterface) {
-  switch (connectionInterface) {
+  return switch (connectionInterface) {
-    case DeviceConnectionInterface.attached:
+    DeviceConnectionInterface.attached => 'attached',
-      return 'attached';
+    DeviceConnectionInterface.wireless => 'wireless',
-    case DeviceConnectionInterface.wireless:
+  };
-      return 'wireless';
-  }
 }
 
 /// A device is a physical hardware that can run a Flutter application.

packages/flutter_tools/lib/src/doctor_validator.dart

@@ -162,47 +162,31 @@ class ValidationResult {
   final List<ValidationMessage> messages;
 
   String get leadingBox {
-    switch (type) {
+    return switch (type) {
-      case ValidationType.crash:
+      ValidationType.crash   => '[☠]',
-        return '[☠]';
+      ValidationType.missing => '[✗]',
-      case ValidationType.missing:
+      ValidationType.success => '[✓]',
-        return '[✗]';
+      ValidationType.notAvailable || ValidationType.partial => '[!]',
-      case ValidationType.success:
+    };
-        return '[✓]';
-      case ValidationType.notAvailable:
-      case ValidationType.partial:
-        return '[!]';
-    }
   }
 
   String get coloredLeadingBox {
-    switch (type) {
+    return globals.terminal.color(leadingBox, switch (type) {
-      case ValidationType.crash:
+      ValidationType.success => TerminalColor.green,
-        return globals.terminal.color(leadingBox, TerminalColor.red);
+      ValidationType.crash || ValidationType.missing => TerminalColor.red,
-      case ValidationType.missing:
+      ValidationType.notAvailable || ValidationType.partial => TerminalColor.yellow,
-        return globals.terminal.color(leadingBox, TerminalColor.red);
+    });
-      case ValidationType.success:
-        return globals.terminal.color(leadingBox, TerminalColor.green);
-      case ValidationType.notAvailable:
-      case ValidationType.partial:
-        return globals.terminal.color(leadingBox, TerminalColor.yellow);
-    }
   }
 
   /// The string representation of the type.
   String get typeStr {
-    switch (type) {
+    return switch (type) {
-      case ValidationType.crash:
+      ValidationType.crash        => 'crash',
-        return 'crash';
+      ValidationType.missing      => 'missing',
-      case ValidationType.missing:
+      ValidationType.success      => 'installed',
-        return 'missing';
+      ValidationType.notAvailable => 'notAvailable',
-      case ValidationType.success:
+      ValidationType.partial      => 'partial',
-        return 'installed';
+    };
-      case ValidationType.notAvailable:
-        return 'notAvailable';
-      case ValidationType.partial:
-        return 'partial';
-    }
   }
 
   @override
@@ -254,25 +238,19 @@ class ValidationMessage {
   bool get isInformation => type == ValidationMessageType.information;
 
   String get indicator {
-    switch (type) {
+    return switch (type) {
-      case ValidationMessageType.error:
+      ValidationMessageType.error => '✗',
-        return '✗';
+      ValidationMessageType.hint => '!',
-      case ValidationMessageType.hint:
+      ValidationMessageType.information => '•',
-        return '!';
+    };
-      case ValidationMessageType.information:
-        return '•';
-    }
   }
 
   String get coloredIndicator {
-    switch (type) {
+    return globals.terminal.color(indicator, switch (type) {
-      case ValidationMessageType.error:
+      ValidationMessageType.error       => TerminalColor.red,
-        return globals.terminal.color(indicator, TerminalColor.red);
+      ValidationMessageType.hint        => TerminalColor.yellow,
-      case ValidationMessageType.hint:
+      ValidationMessageType.information => TerminalColor.green,
-        return globals.terminal.color(indicator, TerminalColor.yellow);
+    });
-      case ValidationMessageType.information:
-        return globals.terminal.color(indicator, TerminalColor.green);
-    }
   }
 
   @override

packages/flutter_tools/lib/src/features.dart

@@ -270,15 +270,11 @@ class Feature {
 
   /// Retrieve the correct setting for the provided `channel`.
   FeatureChannelSetting getSettingForChannel(String channel) {
-    switch (channel) {
+    return switch (channel) {
-      case 'stable':
+      'stable' => stable,
-        return stable;
+      'beta' => beta,
-      case 'beta':
+      'master' || _ => master,
-        return beta;
+    };
-      case 'master':
-      default:
-        return master;
-    }
   }
 }
 

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

@@ -143,27 +143,18 @@ class PlistParser {
   static final RegExp _nonBase64Pattern = RegExp('[^a-zA-Z0-9+/=]+');
 
   Object? _parseXmlNode(XmlElement node) {
-    switch (node.name.local){
+    return switch (node.name.local) {
-      case 'string':
+      'string'  => node.innerText,
-        return node.innerText;
+      'real'    => double.parse(node.innerText),
-      case 'real':
+      'integer' => int.parse(node.innerText),
-        return double.parse(node.innerText);
+      'true'    => true,
-      case 'integer':
+      'false'   => false,
-        return int.parse(node.innerText);
+      'date'    => DateTime.parse(node.innerText),
-      case 'true':
+      'data'    => base64.decode(node.innerText.replaceAll(_nonBase64Pattern, '')),
-        return true;
+      'array'   => node.children.whereType<XmlElement>().map<Object?>(_parseXmlNode).whereType<Object>().toList(),
-      case 'false':
+      'dict'    => _parseXmlDict(node),
-        return false;
+      _         => null,
-      case 'date':
+    };
-        return DateTime.parse(node.innerText);
-      case 'data':
-        return base64.decode(node.innerText.replaceAll(_nonBase64Pattern, ''));
-      case 'array':
-        return node.children.whereType<XmlElement>().map<Object?>(_parseXmlNode).whereType<Object>().toList();
-      case 'dict':
-        return _parseXmlDict(node);
-    }
-    return null;
   }
 
   /// Parses the Plist file located at [plistFilePath] and returns the value

packages/flutter_tools/lib/src/isolated/native_assets/android/native_assets.dart

@@ -156,34 +156,24 @@ Future<void> _copyNativeAssetsAndroid(
 
 /// Get the [Target] for [androidArch].
 Target _getNativeTarget(AndroidArch androidArch) {
-  switch (androidArch) {
+  return switch (androidArch) {
-    case AndroidArch.armeabi_v7a:
+    AndroidArch.armeabi_v7a => Target.androidArm,
-      return Target.androidArm;
+    AndroidArch.arm64_v8a   => Target.androidArm64,
-    case AndroidArch.arm64_v8a:
+    AndroidArch.x86         => Target.androidIA32,
-      return Target.androidArm64;
+    AndroidArch.x86_64      => Target.androidX64,
-    case AndroidArch.x86:
+  };
-      return Target.androidIA32;
-    case AndroidArch.x86_64:
-      return Target.androidX64;
-  }
 }
 
 /// Get the [AndroidArch] for [target].
 AndroidArch _getAndroidArch(Target target) {
-  switch (target) {
+  return switch (target) {
-    case Target.androidArm:
+    Target.androidArm   => AndroidArch.armeabi_v7a,
-      return AndroidArch.armeabi_v7a;
+    Target.androidArm64 => AndroidArch.arm64_v8a,
-    case Target.androidArm64:
+    Target.androidIA32  => AndroidArch.x86,
-      return AndroidArch.arm64_v8a;
+    Target.androidX64   => AndroidArch.x86_64,
-    case Target.androidIA32:
+    Target.androidRiscv64 => throwToolExit('Android RISC-V not yet supported.'),
-      return AndroidArch.x86;
+    _ => throwToolExit('Invalid target: $target.'),
-    case Target.androidX64:
+  };
-      return AndroidArch.x86_64;
-    case Target.androidRiscv64:
-      throwToolExit('Android RISC-V not yet supported.');
-    default:
-      throwToolExit('Invalid target: $target.');
-  }
 }
 
 Map<AssetImpl, KernelAsset> _assetTargetLocations(

packages/flutter_tools/lib/src/isolated/native_assets/ios/native_assets.dart

@@ -124,24 +124,19 @@ Future<List<Uri>> buildNativeAssetsIOS({
 }
 
 IOSSdkImpl _getIOSSdkImpl(EnvironmentType environmentType) {
-  switch (environmentType) {
+  return switch (environmentType) {
-    case EnvironmentType.physical:
+    EnvironmentType.physical  => IOSSdkImpl.iPhoneOS,
-      return IOSSdkImpl.iPhoneOS;
+    EnvironmentType.simulator => IOSSdkImpl.iPhoneSimulator,
-    case EnvironmentType.simulator:
+  };
-      return IOSSdkImpl.iPhoneSimulator;
-  }
 }
 
 /// Extract the [Target] from a [DarwinArch].
 Target _getNativeTarget(DarwinArch darwinArch) {
-  switch (darwinArch) {
+  return switch (darwinArch) {
-    case DarwinArch.armv7:
+    DarwinArch.armv7  => Target.iOSArm,
-      return Target.iOSArm;
+    DarwinArch.arm64  => Target.iOSArm64,
-    case DarwinArch.arm64:
+    DarwinArch.x86_64 => Target.iOSX64,
-      return Target.iOSArm64;
+  };
-    case DarwinArch.x86_64:
-      return Target.iOSX64;
-  }
 }
 
 Map<KernelAssetPath, List<AssetImpl>> _fatAssetTargetLocations(

packages/flutter_tools/lib/src/isolated/native_assets/macos/native_assets.dart

@@ -156,14 +156,11 @@ Future<(Uri? nativeAssetsYaml, List<Uri> dependencies)> buildNativeAssetsMacOS({
 
 /// Extract the [Target] from a [DarwinArch].
 Target _getNativeTarget(DarwinArch darwinArch) {
-  switch (darwinArch) {
+  return switch (darwinArch) {
-    case DarwinArch.arm64:
+    DarwinArch.arm64  => Target.macOSArm64,
-      return Target.macOSArm64;
+    DarwinArch.x86_64 => Target.macOSX64,
-    case DarwinArch.x86_64:
+    DarwinArch.armv7  => throw Exception('Unknown DarwinArch: $darwinArch.'),
-      return Target.macOSX64;
+  };
-    case DarwinArch.armv7:
-      throw Exception('Unknown DarwinArch: $darwinArch.');
-  }
 }
 
 Map<KernelAssetPath, List<AssetImpl>> _fatAssetTargetLocations(

packages/flutter_tools/lib/src/localizations/localizations_utils.dart

@@ -64,29 +64,12 @@ class LocaleInfo implements Comparable<LocaleInfo> {
     /// across various countries. For example, we know Taiwan uses traditional (Hant)
     /// script, so it is safe to apply (Hant) to Taiwanese languages.
     if (deriveScriptCode && scriptCode == null) {
-      switch (languageCode) {
+      scriptCode = switch ((languageCode, countryCode)) {
-        case 'zh': {
+        ('zh', 'CN' || 'SG' || null) => 'Hans',
-          if (countryCode == null) {
+        ('zh', 'TW' || 'HK' || 'MO') => 'Hant',
-            scriptCode = 'Hans';
+        ('sr', null) => 'Cyrl',
-          }
+        _ => null,
-          switch (countryCode) {
+      };
-            case 'CN':
-            case 'SG':
-              scriptCode = 'Hans';
-            case 'TW':
-            case 'HK':
-            case 'MO':
-              scriptCode = 'Hant';
-          }
-          break;
-        }
-        case 'sr': {
-          if (countryCode == null) {
-            scriptCode = 'Cyrl';
-          }
-          break;
-        }
-      }
       // Increment length if we were able to assume a scriptCode.
       if (scriptCode != null) {
         length += 1;

packages/flutter_tools/lib/src/run_hot.dart

@@ -1511,24 +1511,16 @@ String _describePausedIsolates(int pausedIsolatesFound, String serviceEventKind)
     message.write('$pausedIsolatesFound isolates are ');
     plural = true;
   }
-  switch (serviceEventKind) {
+  message.write(switch (serviceEventKind) {
-    case vm_service.EventKind.kPauseStart:
+    vm_service.EventKind.kPauseStart       => 'paused (probably due to --start-paused)',
-      message.write('paused (probably due to --start-paused)');
+    vm_service.EventKind.kPauseExit        => 'paused because ${ plural ? 'they have' : 'it has' } terminated',
-    case vm_service.EventKind.kPauseExit:
+    vm_service.EventKind.kPauseBreakpoint  => 'paused in the debugger on a breakpoint',
-      message.write('paused because ${ plural ? 'they have' : 'it has' } terminated');
+    vm_service.EventKind.kPauseInterrupted => 'paused due in the debugger',
-    case vm_service.EventKind.kPauseBreakpoint:
+    vm_service.EventKind.kPauseException   => 'paused in the debugger after an exception was thrown',
-      message.write('paused in the debugger on a breakpoint');
+    vm_service.EventKind.kPausePostRequest => 'paused',
-    case vm_service.EventKind.kPauseInterrupted:
+    '' => 'paused for various reasons',
-      message.write('paused due in the debugger');
+    _  => 'paused',
-    case vm_service.EventKind.kPauseException:
+  });
-      message.write('paused in the debugger after an exception was thrown');
-    case vm_service.EventKind.kPausePostRequest:
-      message.write('paused');
-    case '':
-      message.write('paused for various reasons');
-    default:
-      message.write('paused');
-  }
   return message.toString();
 }
 

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

@@ -375,22 +375,15 @@ class FlutterTesterTestDevice extends TestDevice {
 }
 
 String _getExitCodeMessage(int exitCode) {
-  switch (exitCode) {
+  return switch (exitCode) {
-    case 1:
+    1     => 'Shell subprocess cleanly reported an error. Check the logs above for an error message.',
-      return 'Shell subprocess cleanly reported an error. Check the logs above for an error message.';
+    0     => 'Shell subprocess ended cleanly. Did main() call exit()?',
-    case 0:
+    -0x0f => 'Shell subprocess crashed with SIGTERM ($exitCode).',     // ProcessSignal.SIGTERM
-      return 'Shell subprocess ended cleanly. Did main() call exit()?';
+    -0x0b => 'Shell subprocess crashed with segmentation fault.',      // ProcessSignal.SIGSEGV
-    case -0x0f: // ProcessSignal.SIGTERM
+    -0x06 => 'Shell subprocess crashed with SIGABRT ($exitCode).',     // ProcessSignal.SIGABRT
-      return 'Shell subprocess crashed with SIGTERM ($exitCode).';
+    -0x02 => 'Shell subprocess terminated by ^C (SIGINT, $exitCode).', // ProcessSignal.SIGINT
-    case -0x0b: // ProcessSignal.SIGSEGV
+    _     => 'Shell subprocess crashed with unexpected exit code $exitCode.',
-      return 'Shell subprocess crashed with segmentation fault.';
+  };
-    case -0x06: // ProcessSignal.SIGABRT
-      return 'Shell subprocess crashed with SIGABRT ($exitCode).';
-    case -0x02: // ProcessSignal.SIGINT
-      return 'Shell subprocess terminated by ^C (SIGINT, $exitCode).';
-    default:
-      return 'Shell subprocess crashed with unexpected exit code $exitCode.';
-  }
 }
 
 StreamChannel<String> _webSocketToStreamChannel(WebSocket webSocket) {

packages/flutter_tools/lib/src/version.dart

@@ -1163,14 +1163,11 @@ class VersionFreshnessValidator {
   /// beta releases happen approximately every month.
   @visibleForTesting
   static Duration versionAgeConsideredUpToDate(String channel) {
-    switch (channel) {
+    return switch (channel) {
-      case 'stable':
+      'stable' => const Duration(days: 365 ~/ 2), // Six months
-        return const Duration(days: 365 ~/ 2); // Six months
+      'beta'   => const Duration(days: 7 * 8),    // Eight weeks
-      case 'beta':
+      _        => const Duration(days: 7 * 3),    // Three weeks
-        return const Duration(days: 7 * 8); // Eight weeks
+    };
-      default:
-        return const Duration(days: 7 * 3); // Three weeks
-    }
   }
 
   /// Execute validations and print warning to [logger] if necessary.

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

@@ -179,13 +179,10 @@ class VisualStudio {
   /// version.
   String? get cmakeGenerator {
     // From https://cmake.org/cmake/help/v3.22/manual/cmake-generators.7.html#visual-studio-generators
-    switch (_majorVersion) {
+    return switch (_majorVersion) {
-      case 17:
+      17 => 'Visual Studio 17 2022',
-        return 'Visual Studio 17 2022';
+      _  => 'Visual Studio 16 2019',
-      case 16:
+    };
-      default:
-        return 'Visual Studio 16 2019';
-    }
   }
 
   /// The path to cl.exe, or null if no Visual Studio installation has

packages/flutter_tools/test/integration.shard/transition_test_utils.dart

@@ -122,25 +122,15 @@ class LogLine {
   }
 
   static String clarify(String line) {
-    return line.runes.map<String>((int rune) {
+    return line.runes.map<String>((int rune) => switch (rune) {
-      if (rune >= 0x20 && rune <= 0x7F) {
+      >= 0x20 && <= 0x7F => String.fromCharCode(rune),
-        return String.fromCharCode(rune);
+      0x00 => '<NUL>',
-      }
+      0x07 => '<BEL>',
-      switch (rune) {
+      0x08 => '<TAB>',
-        case 0x00:
+      0x09 => '<BS>',
-          return '<NUL>';
+      0x0A => '<LF>',
-        case 0x07:
+      0x0D => '<CR>',
-          return '<BEL>';
+      _ => '<${rune.toRadixString(16).padLeft(rune <= 0xFF ? 2 : rune <= 0xFFFF ? 4 : 5, '0')}>',
-        case 0x08:
-          return '<TAB>';
-        case 0x09:
-          return '<BS>';
-        case 0x0A:
-          return '<LF>';
-        case 0x0D:
-          return '<CR>';
-      }
-      return '<${rune.toRadixString(16).padLeft(rune <= 0xFF ? 2 : rune <= 0xFFFF ? 4 : 5, '0')}>';
     }).join();
   }
 }

packages/flutter_tools/test/src/fake_http_client.dart

@@ -20,23 +20,15 @@ enum HttpMethod {
 }
 
 HttpMethod _fromMethodString(String value) {
-  final String name = value.toLowerCase();
+  return switch (value.toLowerCase()) {
-  switch (name) {
+    'get'    => HttpMethod.get,
-    case 'get':
+    'put'    => HttpMethod.put,
-      return HttpMethod.get;
+    'delete' => HttpMethod.delete,
-    case 'put':
+    'post'   => HttpMethod.post,
-      return HttpMethod.put;
+    'patch'  => HttpMethod.patch,
-    case 'delete':
+    'head'   => HttpMethod.head,
-      return HttpMethod.delete;
+    _ => throw StateError('Unrecognized HTTP method $value'),
-    case 'post':
+  };
-      return HttpMethod.post;
-    case 'patch':
-      return HttpMethod.patch;
-    case 'head':
-      return HttpMethod.head;
-    default:
-      throw StateError('Unrecognized HTTP method $value');
-  }
 }
 
 String _toMethodString(HttpMethod method) {