Implementing switch expressions in `flutter/test/` (#144580)

Migrates test code to new `switch` syntax.

packages/flutter/test/cupertino/route_test.dart

@@ -2662,21 +2662,14 @@ class _TestPostRouteCancelState extends State<_TestPostRouteCancel> {
   Widget build(BuildContext context) {
     return CupertinoApp(
       initialRoute: 'home',
-      onGenerateRoute: (RouteSettings settings) {
-        return CupertinoPageRoute<void>(
+      onGenerateRoute: (RouteSettings settings) => CupertinoPageRoute<void>(
         settings: settings,
-          builder: (BuildContext context) {
-            switch (settings.name) {
-              case 'home':
-                return _buildHome(context);
-              case 'sub':
-                return _buildSub(context);
-              default:
-                throw UnimplementedError();
-            }
-          },
-        );
+        builder: (BuildContext context) => switch (settings.name) {
+          'home' => _buildHome(context),
+          'sub'  => _buildSub(context),
+          _ => throw UnimplementedError(),
         },
+      ),
     );
   }
 }

packages/flutter/test/material/dropdown_menu_test.dart

@@ -1119,17 +1119,10 @@ void main() {
     await tester.tap(find.byType(DropdownMenu<TestMenu>));
     await tester.pump();
 
-    late final bool isMobile;
-    switch (themeData.platform) {
-      case TargetPlatform.android:
-      case TargetPlatform.iOS:
-      case TargetPlatform.fuchsia:
-        isMobile = true;
-      case TargetPlatform.macOS:
-      case TargetPlatform.linux:
-      case TargetPlatform.windows:
-        isMobile = false;
-    }
+    final bool isMobile = switch (themeData.platform) {
+      TargetPlatform.android || TargetPlatform.iOS || TargetPlatform.fuchsia => true,
+      TargetPlatform.macOS || TargetPlatform.linux || TargetPlatform.windows => false,
+    };
     int expectedCount = isMobile ? 0 : 1;
 
     // Test onSelected on key press

packages/flutter/test/rendering/viewport_test.dart

@@ -1259,12 +1259,10 @@ void main() {
       }
 
       final RenderBox renderBox = renderObject as RenderBox;
-      switch (axis) {
-        case Axis.horizontal:
-          return renderBox.size.width;
-        case Axis.vertical:
-          return renderBox.size.height;
-      }
+      return switch (axis) {
+        Axis.horizontal => renderBox.size.width,
+        Axis.vertical   => renderBox.size.height,
+      };
     }
 
     group('animated: $animated, scrollDirection: $axis', () {

packages/flutter/test/services/fake_platform_views.dart

@@ -188,23 +188,16 @@ class FakeAndroidPlatformViewsController {
   }
 
   Future<dynamic> _onMethodCall(MethodCall call) {
-    switch (call.method) {
-      case 'create':
-        return _create(call);
-      case 'dispose':
-        return _dispose(call);
-      case 'resize':
-        return _resize(call);
-      case 'touch':
-        return _touch(call);
-      case 'setDirection':
-        return _setDirection(call);
-      case 'clearFocus':
-        return _clearFocus(call);
-      case 'offset':
-        return _offset(call);
-    }
-    return Future<dynamic>.sync(() => null);
+    return switch (call.method) {
+      'create'       => _create(call),
+      'dispose'      => _dispose(call),
+      'resize'       => _resize(call),
+      'touch'        => _touch(call),
+      'setDirection' => _setDirection(call),
+      'clearFocus'   => _clearFocus(call),
+      'offset'       => _offset(call),
+      _ => Future<dynamic>.sync(() => null),
+    };
   }
 
   Future<dynamic> _create(MethodCall call) async {
@@ -400,17 +393,13 @@ class FakeIosPlatformViewsController {
   }
 
   Future<dynamic> _onMethodCall(MethodCall call) {
-    switch (call.method) {
-      case 'create':
-        return _create(call);
-      case 'dispose':
-        return _dispose(call);
-      case 'acceptGesture':
-        return _acceptGesture(call);
-      case 'rejectGesture':
-        return _rejectGesture(call);
-    }
-    return Future<dynamic>.sync(() => null);
+    return switch (call.method) {
+      'create'        => _create(call),
+      'dispose'       => _dispose(call),
+      'acceptGesture' => _acceptGesture(call),
+      'rejectGesture' => _rejectGesture(call),
+      _ => Future<dynamic>.sync(() => null),
+    };
   }
 
   Future<dynamic> _create(MethodCall call) async {
@@ -503,17 +492,13 @@ class FakeMacosPlatformViewsController {
   }
 
   Future<dynamic> _onMethodCall(MethodCall call) {
-    switch (call.method) {
-      case 'create':
-        return _create(call);
-      case 'dispose':
-        return _dispose(call);
-      case 'acceptGesture':
-        return _acceptGesture(call);
-      case 'rejectGesture':
-        return _rejectGesture(call);
-    }
-    return Future<dynamic>.sync(() => null);
+    return switch (call.method) {
+      'create'        => _create(call),
+      'dispose'       => _dispose(call),
+      'acceptGesture' => _acceptGesture(call),
+      'rejectGesture' => _rejectGesture(call),
+      _ => Future<dynamic>.sync(() => null),
+    };
   }
 
   Future<dynamic> _create(MethodCall call) async {

packages/flutter/test/services/raw_keyboard_test.dart

@@ -2241,22 +2241,15 @@ void main() {
 
     // How modifiers are interpreted depends upon the keyCode for GLFW.
     int keyCodeForModifier(int modifier, {required bool isLeft}) {
-      switch (modifier) {
-        case GLFWKeyHelper.modifierAlt:
-          return isLeft ? 342 : 346;
-        case GLFWKeyHelper.modifierShift:
-          return isLeft ? 340 : 344;
-        case GLFWKeyHelper.modifierControl:
-          return isLeft ? 341 : 345;
-        case GLFWKeyHelper.modifierMeta:
-          return isLeft ? 343 : 347;
-        case GLFWKeyHelper.modifierNumericPad:
-          return 282;
-        case GLFWKeyHelper.modifierCapsLock:
-          return 280;
-        default:
-          return 65; // keyA
-      }
+      return switch (modifier) {
+        GLFWKeyHelper.modifierAlt     => isLeft ? 342 : 346,
+        GLFWKeyHelper.modifierShift   => isLeft ? 340 : 344,
+        GLFWKeyHelper.modifierControl => isLeft ? 341 : 345,
+        GLFWKeyHelper.modifierMeta    => isLeft ? 343 : 347,
+        GLFWKeyHelper.modifierNumericPad => 282,
+        GLFWKeyHelper.modifierCapsLock   => 280,
+        _ => 65, // keyA
+      };
     }
 
     test('modifier keys are recognized individually', () {
@@ -2473,22 +2466,15 @@ void main() {
 
     // How modifiers are interpreted depends upon the keyCode for GTK.
     int keyCodeForModifier(int modifier, {required bool isLeft}) {
-      switch (modifier) {
-        case GtkKeyHelper.modifierMod1:
-          return 65513;
-        case GtkKeyHelper.modifierShift:
-          return isLeft ? 65505 : 65506;
-        case GtkKeyHelper.modifierControl:
-          return isLeft ? 65507 : 65508;
-        case GtkKeyHelper.modifierMeta:
-          return isLeft ? 65515 : 65516;
-        case GtkKeyHelper.modifierMod2:
-          return 65407;
-        case GtkKeyHelper.modifierCapsLock:
-          return 65509;
-        default:
-          return 65; // keyA
-      }
+      return switch (modifier) {
+        GtkKeyHelper.modifierShift    => isLeft ? 65505 : 65506,
+        GtkKeyHelper.modifierControl  => isLeft ? 65507 : 65508,
+        GtkKeyHelper.modifierMeta     => isLeft ? 65515 : 65516,
+        GtkKeyHelper.modifierMod1     => 65513,
+        GtkKeyHelper.modifierMod2     => 65407,
+        GtkKeyHelper.modifierCapsLock => 65509,
+        _ => 65, // keyA
+      };
     }
 
     test('modifier keys are recognized individually', () {

packages/flutter/test/widgets/dismissible_test.dart

@@ -119,32 +119,22 @@ Future<void> dismissElement(WidgetTester tester, Finder finder, { required AxisD
 }
 
 Future<void> dragElement(WidgetTester tester, Finder finder, { required AxisDirection gestureDirection, required double amount }) async {
-  Offset delta;
-  switch (gestureDirection) {
-    case AxisDirection.left:
-      delta = Offset(-amount, 0.0);
-    case AxisDirection.right:
-      delta = Offset(amount, 0.0);
-    case AxisDirection.up:
-      delta = Offset(0.0, -amount);
-    case AxisDirection.down:
-      delta = Offset(0.0, amount);
-  }
+  final Offset delta = switch (gestureDirection) {
+    AxisDirection.left  => Offset(-amount, 0.0),
+    AxisDirection.right => Offset(amount, 0.0),
+    AxisDirection.up    => Offset(0.0, -amount),
+    AxisDirection.down  => Offset(0.0, amount),
+  };
   await tester.drag(finder, delta);
 }
 
 Future<void> flingElement(WidgetTester tester, Finder finder, { required AxisDirection gestureDirection, double initialOffsetFactor = 0.0 }) async {
-  Offset delta;
-  switch (gestureDirection) {
-    case AxisDirection.left:
-      delta = const Offset(-300.0, 0.0);
-    case AxisDirection.right:
-      delta = const Offset(300.0, 0.0);
-    case AxisDirection.up:
-      delta = const Offset(0.0, -300.0);
-    case AxisDirection.down:
-      delta = const Offset(0.0, 300.0);
-  }
+  final Offset delta = switch (gestureDirection) {
+    AxisDirection.left  => const Offset(-300, 0.0),
+    AxisDirection.right => const Offset(300, 0.0),
+    AxisDirection.up    => const Offset(0.0, -300),
+    AxisDirection.down  => const Offset(0.0, 300),
+  };
   await tester.fling(finder, delta, 1000.0, initialOffset: delta * initialOffsetFactor);
 }
 
@@ -213,17 +203,12 @@ Future<void> checkFlingItemAfterMovement(
 }
 
 Future<void> rollbackElement(WidgetTester tester, Finder finder, { required AxisDirection gestureDirection, double initialOffsetFactor = 0.0 }) async {
-  Offset delta;
-  switch (gestureDirection) {
-    case AxisDirection.left:
-      delta = const Offset(-30.0, 0.0);
-    case AxisDirection.right:
-      delta = const Offset(30.0, 0.0);
-    case AxisDirection.up:
-      delta = const Offset(0.0, -30.0);
-    case AxisDirection.down:
-      delta = const Offset(0.0, 30.0);
-  }
+  final Offset delta = switch (gestureDirection) {
+    AxisDirection.left  => const Offset(-30.0, 0.0),
+    AxisDirection.right => const Offset(30.0, 0.0),
+    AxisDirection.up    => const Offset(0.0, -30.0),
+    AxisDirection.down  => const Offset(0.0, 30.0),
+  };
   await tester.fling(finder, delta, 1000.0, initialOffset: delta * initialOffsetFactor);
 }
 

packages/flutter/test/widgets/html_element_view_test.dart

@@ -442,13 +442,11 @@ class FakePlatformViewRegistry implements ui_web.PlatformViewRegistry {
   }
 
   Future<dynamic> _onMethodCall(MethodCall call) {
-    switch (call.method) {
-      case 'create':
-        return _create(call);
-      case 'dispose':
-        return _dispose(call);
-    }
-    return Future<dynamic>.sync(() => null);
+    return switch (call.method) {
+      'create'  => _create(call),
+      'dispose' => _dispose(call),
+      _ => Future<dynamic>.sync(() => null),
+    };
   }
 
   Future<dynamic> _create(MethodCall call) async {

packages/flutter/test/widgets/image_resolution_test.dart

@@ -38,23 +38,16 @@ class TestAssetBundle extends CachingAssetBundle {
 
   @override
   Future<ByteData> load(String key) {
-    late ByteData data;
-    switch (key) {
-      case 'AssetManifest.bin':
-        data = manifest;
-      case 'assets/image.png':
-        data = testByteData(1.0);
-      case 'assets/1.0x/image.png':
-        data = testByteData(10.0); // see "...with a main asset and a 1.0x asset"
-      case 'assets/1.5x/image.png':
-        data = testByteData(1.5);
-      case 'assets/2.0x/image.png':
-        data = testByteData(2.0);
-      case 'assets/3.0x/image.png':
-        data = testByteData(3.0);
-      case 'assets/4.0x/image.png':
-        data = testByteData(4.0);
-    }
+    final ByteData data = switch (key) {
+      'AssetManifest.bin'     => manifest,
+      'assets/image.png'      => testByteData(1.0),
+      'assets/1.0x/image.png' => testByteData(10.0), // see "...with a main asset and a 1.0x asset"
+      'assets/1.5x/image.png' => testByteData(1.5),
+      'assets/2.0x/image.png' => testByteData(2.0),
+      'assets/3.0x/image.png' => testByteData(3.0),
+      'assets/4.0x/image.png' => testByteData(4.0),
+      _ => throw ArgumentError('Unexpected key: $key'),
+    };
     return SynchronousFuture<ByteData>(data);
   }
 

packages/flutter/test/widgets/page_forward_transitions_test.dart

@@ -199,12 +199,10 @@ void main() {
   testWidgets('Check onstage/offstage handling of barriers around transitions', (WidgetTester tester) async {
     await tester.pumpWidget(
       MaterialApp(
-        onGenerateRoute: (RouteSettings settings) {
-          switch (settings.name) {
-            case '/': return TestRoute<void>(settings: settings, child: const Text('A'));
-            case '/1': return TestRoute<void>(settings: settings, barrierColor: const Color(0xFFFFFF00), child: const Text('B'));
-          }
-          return null;
+        onGenerateRoute: (RouteSettings settings) => switch (settings.name) {
+          '/'  => TestRoute<void>(settings: settings, child: const Text('A')),
+          '/1' => TestRoute<void>(settings: settings, barrierColor: const Color(0xFFFFFF00), child: const Text('B')),
+          _ => null,
         },
       ),
     );

packages/flutter/test/widgets/render_object_widget_test.dart

@@ -26,13 +26,10 @@ class TestOrientedBox extends SingleChildRenderObjectWidget {
   const TestOrientedBox({ super.key, super.child });
 
   Decoration _getDecoration(BuildContext context) {
-    final Orientation orientation = MediaQuery.orientationOf(context);
-    switch (orientation) {
-      case Orientation.landscape:
-        return const BoxDecoration(color: Color(0xFF00FF00));
-      case Orientation.portrait:
-        return const BoxDecoration(color: Color(0xFF0000FF));
-    }
+    return switch (MediaQuery.orientationOf(context)) {
+      Orientation.landscape => const BoxDecoration(color: Color(0xFF00FF00)),
+      Orientation.portrait  => const BoxDecoration(color: Color(0xFF0000FF)),
+    };
   }
 
   @override

packages/flutter/test/widgets/slotted_render_object_widget_test.dart

@@ -286,14 +286,11 @@ class _Diagonal extends RenderObjectWidget with SlottedMultiChildRenderObjectWid
 
   @override
   Widget? childForSlot(_DiagonalSlot? slot) {
-    switch (slot) {
-      case null:
-        return nullSlot;
-      case _DiagonalSlot.topLeft:
-        return topLeft;
-      case _DiagonalSlot.bottomRight:
-        return bottomRight;
-    }
+    return switch (slot) {
+      null => nullSlot,
+      _DiagonalSlot.topLeft     => topLeft,
+      _DiagonalSlot.bottomRight => bottomRight,
+    };
   }
 
   @override

packages/flutter/test/widgets/text_selection_test.dart

@@ -2008,14 +2008,17 @@ class TextSelectionControlsSpy extends TextSelectionControls {
 
   @override
   Widget buildHandle(BuildContext context, TextSelectionHandleType type, double textLineHeight, [VoidCallback? onTap]) {
-    switch (type) {
-      case TextSelectionHandleType.left:
-        return ElevatedButton(onPressed: onTap, child: Text('height ${textLineHeight.toInt()}', key: leftHandleKey));
-      case TextSelectionHandleType.right:
-        return ElevatedButton(onPressed: onTap, child: Text('height ${textLineHeight.toInt()}', key: rightHandleKey));
-      case TextSelectionHandleType.collapsed:
-        return ElevatedButton(onPressed: onTap, child: Text('height ${textLineHeight.toInt()}', key: collapsedHandleKey));
-    }
+    return ElevatedButton(
+      onPressed: onTap,
+      child: Text(
+        key: switch (type) {
+          TextSelectionHandleType.left      => leftHandleKey,
+          TextSelectionHandleType.right     => rightHandleKey,
+          TextSelectionHandleType.collapsed => collapsedHandleKey,
+        },
+        'height ${textLineHeight.toInt()}',
+      ),
+    );
   }
 
   @override