[a11y] Make sure RenderFractionalTranslation updates its semantics after the translation field is set (#48985)

dev/bots/test/common.dart

@@ -13,7 +13,7 @@ export 'package:test/test.dart' hide TypeMatcher, isInstanceOf;
 // TODO(ianh): Remove this file once https://github.com/dart-lang/matcher/issues/98 is fixed
 
 /// A matcher that compares the type of the actual value to the type argument T.
-test_package.TypeMatcher<T> isInstanceOf<T>() => isA<T>();
+Matcher isInstanceOf<T>() => test_package.TypeMatcher<T>();
 
 void tryToDelete(Directory directory) {
   // This should not be necessary, but it turns out that

dev/bots/test/prepare_package_test.dart

@@ -25,7 +25,7 @@ void main() {
         expectAsync1((List<String> commandLine) async {
           return processRunner.runProcess(commandLine);
         })(<String>['this_executable_better_not_exist_2857632534321']),
-        throwsA(isA<PreparePackageException>()));
+        throwsA(isInstanceOf<PreparePackageException>()));
     try {
       await processRunner.runProcess(<String>['this_executable_better_not_exist_2857632534321']);
     } on PreparePackageException catch (e) {
@@ -64,7 +64,7 @@ void main() {
             expectAsync1((List<String> commandLine) async {
               return processRunner.runProcess(commandLine);
             })(<String>['echo', 'test']),
-            throwsA(isA<PreparePackageException>()));
+            throwsA(isInstanceOf<PreparePackageException>()));
       });
     });
     group('ArchiveCreator for $platformName', () {
@@ -185,7 +185,8 @@ void main() {
           'git reset --hard $testRef': <ProcessResult>[ProcessResult(0, -1, 'output2', '')],
         };
         processManager.fakeResults = calls;
-        expect(expectAsync0(creator.initializeRepo), throwsA(isA<PreparePackageException>()));
+        expect(expectAsync0(creator.initializeRepo),
+            throwsA(isInstanceOf<PreparePackageException>()));
       });
 
       test('non-strict mode calls the right commands', () async {

dev/devicelab/test/common.dart

@@ -11,4 +11,4 @@ export 'package:test/test.dart' hide TypeMatcher, isInstanceOf;
 // TODO(ianh): Remove this file once https://github.com/dart-lang/matcher/issues/98 is fixed
 
 /// A matcher that compares the type of the actual value to the type argument T.
-test_package.TypeMatcher<T> isInstanceOf<T>() => isA<T>();
+Matcher isInstanceOf<T>() => test_package.TypeMatcher<T>();

dev/integration_tests/android_semantics_testing/lib/src/flutter_test_alternative.dart

@@ -11,4 +11,4 @@ import 'package:test/test.dart' as test_package show TypeMatcher;
 export 'package:test/test.dart' hide TypeMatcher, isInstanceOf;
 
 /// A matcher that compares the type of the actual value to the type argument T.
-test_package.TypeMatcher<T> isInstanceOf<T>() => isA<T>();
+Matcher isInstanceOf<T>() => test_package.TypeMatcher<T>();

dev/tools/test/common.dart

@@ -13,7 +13,7 @@ export 'package:test/test.dart' hide TypeMatcher, isInstanceOf;
 // TODO(ianh): Remove this file once https://github.com/dart-lang/matcher/issues/98 is fixed
 
 /// A matcher that compares the type of the actual value to the type argument T.
-test_package.TypeMatcher<T> isInstanceOf<T>() => isA<T>();
+Matcher isInstanceOf<T>() => test_package.TypeMatcher<T>();
 
 void tryToDelete(Directory directory) {
   // This should not be necessary, but it turns out that

dev/tools/vitool/test/vitool_test.dart

@@ -17,7 +17,7 @@ void main() {
   test('parsePixels', () {
     expect(parsePixels('23px'), 23);
     expect(parsePixels('9px'), 9);
-    expect(() { parsePixels('9pt'); }, throwsArgumentError);
+    expect(() { parsePixels('9pt'); }, throwsA(isInstanceOf<ArgumentError>()));
   });
 
   test('parsePoints', () {

examples/flutter_gallery/lib/demo/cupertino/cupertino_picker_demo.dart

@@ -108,7 +108,6 @@ class _CupertinoPickerDemoState extends State<CupertinoPickerDemo> {
       onTap: () async {
         await showCupertinoModalPopup<void>(
           context: context,
-          semanticsDismissible: true,
           builder: (BuildContext context) {
             return _BottomPicker(
               child: CupertinoPicker(
@@ -145,7 +144,6 @@ class _CupertinoPickerDemoState extends State<CupertinoPickerDemo> {
       onTap: () {
         showCupertinoModalPopup<void>(
           context: context,
-          semanticsDismissible: true,
           builder: (BuildContext context) {
             return _BottomPicker(
               child: CupertinoTimerPicker(
@@ -178,7 +176,6 @@ class _CupertinoPickerDemoState extends State<CupertinoPickerDemo> {
       onTap: () {
         showCupertinoModalPopup<void>(
           context: context,
-          semanticsDismissible: true,
           builder: (BuildContext context) {
             return _BottomPicker(
               child: CupertinoDatePicker(
@@ -210,7 +207,6 @@ class _CupertinoPickerDemoState extends State<CupertinoPickerDemo> {
       onTap: () {
         showCupertinoModalPopup<void>(
           context: context,
-          semanticsDismissible: true,
           builder: (BuildContext context) {
             return _BottomPicker(
               child: CupertinoDatePicker(
@@ -242,7 +238,6 @@ class _CupertinoPickerDemoState extends State<CupertinoPickerDemo> {
       onTap: () {
         showCupertinoModalPopup<void>(
           context: context,
-          semanticsDismissible: true,
           builder: (BuildContext context) {
             return _BottomPicker(
               child: CupertinoDatePicker(

packages/flutter/lib/src/cupertino/picker.dart

@@ -35,8 +35,7 @@ const double _kOverAndUnderCenterOpacity = 0.447;
 /// that child the initially selected child.
 ///
 /// Can be used with [showCupertinoModalPopup] to display the picker modally at the
-/// bottom of the screen. When calling [showCupertinoModalPopup], be sure to set
+/// bottom of the screen.
-/// `semanticsDismissible` to true to enable dismissing the modal via semantics.
 ///
 /// Sizes itself to its parent. All children are sized to the same size based
 /// on [itemExtent].

packages/flutter/lib/src/cupertino/route.dart

@@ -792,18 +792,14 @@ class _CupertinoModalPopupRoute<T> extends PopupRoute<T> {
     this.barrierColor,
     this.barrierLabel,
     this.builder,
-    bool semanticsDismissible,
     ImageFilter filter,
     RouteSettings settings,
   }) : super(
          filter: filter,
          settings: settings,
-       ) {
+       );
-    _semanticsDismissible = semanticsDismissible;
-  }
 
   final WidgetBuilder builder;
-  bool _semanticsDismissible;
 
   @override
   final String barrierLabel;
@@ -815,7 +811,7 @@ class _CupertinoModalPopupRoute<T> extends PopupRoute<T> {
   bool get barrierDismissible => true;
 
   @override
-  bool get semanticsDismissible => _semanticsDismissible ?? false;
+  bool get semanticsDismissible => false;
 
   @override
   Duration get transitionDuration => _kModalPopupTransitionDuration;
@@ -875,9 +871,6 @@ class _CupertinoModalPopupRoute<T> extends PopupRoute<T> {
 /// popup to the [Navigator] furthest from or nearest to the given `context`. It
 /// is `false` by default.
 ///
-/// The `semanticsDismissble` argument is used to determine whether the
-/// semantics of the modal barrier are included in the semantics tree.
-///
 /// The `builder` argument typically builds a [CupertinoActionSheet] widget.
 /// Content below the widget is dimmed with a [ModalBarrier]. The widget built
 /// by the `builder` does not share a context with the location that
@@ -898,7 +891,6 @@ Future<T> showCupertinoModalPopup<T>({
   @required WidgetBuilder builder,
   ImageFilter filter,
   bool useRootNavigator = true,
-  bool semanticsDismissible,
 }) {
   assert(useRootNavigator != null);
   return Navigator.of(context, rootNavigator: useRootNavigator).push(
@@ -907,7 +899,6 @@ Future<T> showCupertinoModalPopup<T>({
       barrierLabel: 'Dismiss',
       builder: builder,
       filter: filter,
-      semanticsDismissible: semanticsDismissible,
     ),
   );
 }

packages/flutter/lib/src/cupertino/segmented_control.dart

@@ -61,8 +61,6 @@ const Duration _kFadeDuration = Duration(milliseconds: 165);
 ///
 /// See also:
 ///
-///  * [CupertinoSegmentedControl], a segmented control widget in the style used
-///    up until iOS 13.
 ///  * <https://developer.apple.com/design/human-interface-guidelines/ios/controls/segmented-controls/>
 class CupertinoSegmentedControl<T> extends StatefulWidget {
   /// Creates an iOS-style segmented control bar.

packages/flutter/lib/src/cupertino/sliding_segmented_control.dart

@@ -118,8 +118,6 @@ class _FontWeightTween extends Tween<FontWeight> {
 ///
 /// See also:
 ///
-///  * [CupertinoSlidingSegmentedControl], a segmented control widget in the
-///    style introduced in iOS 13.
 ///  * <https://developer.apple.com/design/human-interface-guidelines/ios/controls/segmented-controls/>
 class CupertinoSlidingSegmentedControl<T> extends StatefulWidget {
   /// Creates an iOS-style segmented control bar.

packages/flutter/lib/src/painting/image_cache.dart

@@ -32,7 +32,7 @@ const int _kDefaultSizeBytes = 100 << 20; // 100 MiB
 /// {@tool snippet}
 ///
 /// This sample shows how to supply your own caching logic and replace the
-/// global [imageCache] variable.
+/// global [imageCache] varible.
 ///
 /// ```dart
 /// /// This is the custom implementation of [ImageCache] where we can override
@@ -64,6 +64,7 @@ const int _kDefaultSizeBytes = 100 << 20; // 100 MiB
 /// }
 /// ```
 /// {@end-tool}
+
 class ImageCache {
   final Map<Object, _PendingImage> _pendingImages = <Object, _PendingImage>{};
   final Map<Object, _CachedImage> _cache = <Object, _CachedImage>{};
@@ -140,13 +141,12 @@ class ImageCache {
   }
 
   /// Evicts a single entry from the cache, returning true if successful.
-  /// Pending images waiting for completion are removed as well, returning true
+  /// Pending images waiting for completion are removed as well, returning true if successful.
-  /// if successful.
   ///
-  /// When a pending image is removed the listener on it is removed as well to
+  /// When a pending image is removed the listener on it is removed as well to prevent
-  /// prevent it from adding itself to the cache if it eventually completes.
+  /// it from adding itself to the cache if it eventually completes.
   ///
-  /// The `key` must be equal to an object used to cache an image in
+  /// The [key] must be equal to an object used to cache an image in
   /// [ImageCache.putIfAbsent].
   ///
   /// If the key is not immediately available, as is common, consider using

packages/flutter/lib/src/painting/image_stream.dart

@@ -15,7 +15,7 @@ import 'package:flutter/scheduler.dart';
 /// actual data of the image once it has been obtained.
 @immutable
 class ImageInfo {
-  /// Creates an [ImageInfo] object for the given [image] and [scale].
+  /// Creates an [ImageInfo] object for the given image and scale.
   ///
   /// Both the image and the scale must not be null.
   const ImageInfo({ @required this.image, this.scale = 1.0 })
@@ -35,9 +35,9 @@ class ImageInfo {
   ///
   /// For example, if this is 2.0 it means that there are four image pixels for
   /// every one logical pixel, and the image's actual width and height (as given
-  /// by the [dart:ui.Image.width] and [dart:ui.Image.height] properties) are
+  /// by the [dart:ui.Image.width] and [dart:ui.Image.height] properties) are double the
-  /// double the height and width that should be used when painting the image
+  /// height and width that should be used when painting the image (e.g. in the
-  /// (e.g. in the arguments given to [Canvas.drawImage]).
+  /// arguments given to [Canvas.drawImage]).
   final double scale;
 
   @override
@@ -58,11 +58,11 @@ class ImageInfo {
 
 /// Interface for receiving notifications about the loading of an image.
 ///
-/// This class overrides [operator ==] and [hashCode] to compare the individual
+/// This class overrides `operator ==` and `hashCode` to compare the individual
 /// callbacks in the listener, meaning that if you add an instance of this class
 /// as a listener (e.g. via [ImageStream.addListener]), you can instantiate a
 /// _different_ instance of this class when you remove the listener, and the
-/// listener will be properly removed as long as all associated callbacks are
+/// listener will be properly removed as long all associated callbacks are
 /// equal.
 ///
 /// Used by [ImageStream] and [ImageStreamCompleter].

packages/flutter/lib/src/rendering/editable.dart

@@ -409,14 +409,8 @@ class RenderEditable extends RenderBox with RelayoutWhenSystemFontsChangeMixin {
   ) {
     // Changes made by the keyboard can sometimes be "out of band" for listening
     // components, so always send those events, even if we didn't think it
-    // changed. Also, focusing an empty field is sent as a selection change even
+    // changed.
-    // if the selection offset didn't change.
+    if (nextSelection == selection && cause != SelectionChangedCause.keyboard) {
-    final bool focusingEmpty = nextSelection.baseOffset == 0
-      && nextSelection.extentOffset == 0
-      && !hasFocus;
-    if (nextSelection == selection
-        && cause != SelectionChangedCause.keyboard
-        && !focusingEmpty) {
       return;
     }
     if (onSelectionChanged != null) {

packages/flutter/lib/src/rendering/proxy_box.dart

@@ -2472,6 +2472,7 @@ class RenderFractionalTranslation extends RenderProxyBox {
       return;
     _translation = value;
     markNeedsPaint();
+    markNeedsSemanticsUpdate();
   }
 
   @override

packages/flutter/test/animation/futures_test.dart

@@ -172,10 +172,10 @@ void main() {
     final TickerFuture f = controller1.forward();
     await tester.pump(); // start ticker
     await tester.pump(const Duration(milliseconds: 200)); // end ticker
-    expect(f.asStream().single, isA<Future<void>>());
+    expect(f.asStream().single, isInstanceOf<Future<void>>());
     await f.catchError((dynamic e) { throw 'do not reach'; });
     expect(await f.then<bool>((_) => true), isTrue);
-    expect(f.whenComplete(() => false), isA<Future<void>>());
+    expect(f.whenComplete(() => false), isInstanceOf<Future<void>>());
-    expect(f.timeout(const Duration(seconds: 5)), isA<Future<void>>());
+    expect(f.timeout(const Duration(seconds: 5)), isInstanceOf<Future<void>>());
   });
 }

packages/flutter/test/cupertino/picker_test.dart

@@ -153,6 +153,7 @@ void main() {
     testWidgets(
       'scrolling calls onSelectedItemChanged and triggers haptic feedback',
       (WidgetTester tester) async {
+        debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
         final List<int> selectedItems = <int>[];
         final List<MethodCall> systemCalls = <MethodCall>[];
 
@@ -199,11 +200,15 @@ void main() {
             arguments: 'HapticFeedbackType.selectionClick',
           ),
         );
-    }, variant: TargetPlatformVariant.only(TargetPlatform.iOS));
+
+        debugDefaultTargetPlatformOverride = null;
+      },
+    );
 
     testWidgets(
       'do not trigger haptic effects on non-iOS devices',
       (WidgetTester tester) async {
+        debugDefaultTargetPlatformOverride = TargetPlatform.android;
         final List<int> selectedItems = <int>[];
         final List<MethodCall> systemCalls = <MethodCall>[];
 
@@ -233,9 +238,13 @@ void main() {
         await tester.drag(find.text('0'), const Offset(0.0, -100.0));
         expect(selectedItems, <int>[1]);
         expect(systemCalls, isEmpty);
-    }, variant: TargetPlatformVariant(TargetPlatform.values.where((TargetPlatform platform) => platform != TargetPlatform.iOS).toSet()));
+
+        debugDefaultTargetPlatformOverride = null;
+      },
+    );
 
     testWidgets('a drag in between items settles back', (WidgetTester tester) async {
+      debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
       final FixedExtentScrollController controller =
           FixedExtentScrollController(initialItem: 10);
       final List<int> selectedItems = <int>[];
@@ -288,9 +297,11 @@ void main() {
         moreOrLessEquals(350.0, epsilon: 0.5),
       );
       expect(selectedItems, <int>[9]);
-    }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+      debugDefaultTargetPlatformOverride = null;
+    });
 
     testWidgets('a big fling that overscrolls springs back', (WidgetTester tester) async {
+      debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
       final FixedExtentScrollController controller =
           FixedExtentScrollController(initialItem: 10);
       final List<int> selectedItems = <int>[];
@@ -346,6 +357,8 @@ void main() {
         // Falling back to 0 shouldn't produce more callbacks.
         <int>[8, 6, 4, 2, 0],
       );
-    }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+
+      debugDefaultTargetPlatformOverride = null;
+    });
   });
 }

packages/flutter/test/cupertino/refresh_test.dart

@@ -74,6 +74,8 @@ void main() {
 
   final VoidCallback uiTestGroup = () {
     testWidgets("doesn't invoke anything without user interaction", (WidgetTester tester) async {
+      debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
+
       await tester.pumpWidget(
         Directionality(
           textDirection: TextDirection.ltr,
@@ -94,9 +96,13 @@ void main() {
         tester.getTopLeft(find.widgetWithText(Container, '0')),
         const Offset(0.0, 0.0),
       );
-    }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+
+      debugDefaultTargetPlatformOverride = null;
+    });
 
     testWidgets('calls the indicator builder when starting to overscroll', (WidgetTester tester) async {
+      debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
+
       await tester.pumpWidget(
         Directionality(
           textDirection: TextDirection.ltr,
@@ -130,11 +136,15 @@ void main() {
         tester.getTopLeft(find.widgetWithText(Container, '0')),
         const Offset(0.0, 50.0),
       );
-    }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+
+      debugDefaultTargetPlatformOverride = null;
+    });
 
     testWidgets(
       "don't call the builder if overscroll doesn't move slivers like on Android",
       (WidgetTester tester) async {
+        debugDefaultTargetPlatformOverride = TargetPlatform.android;
+
         await tester.pumpWidget(
           Directionality(
             textDirection: TextDirection.ltr,
@@ -159,9 +169,14 @@ void main() {
           tester.getTopLeft(find.widgetWithText(Container, '0')),
           const Offset(0.0, 0.0),
         );
-    }, variant: TargetPlatformVariant.only(TargetPlatform.android));
+
+        debugDefaultTargetPlatformOverride = null;
+      },
+    );
 
     testWidgets('let the builder update as canceled drag scrolls away', (WidgetTester tester) async {
+      debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
+
       await tester.pumpWidget(
         Directionality(
           textDirection: TextDirection.ltr,
@@ -213,9 +228,13 @@ void main() {
         tester.getTopLeft(find.widgetWithText(Container, '0')),
         const Offset(0.0, 0.0),
       );
-    }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+
+      debugDefaultTargetPlatformOverride = null;
+    });
 
     testWidgets('drag past threshold triggers refresh task', (WidgetTester tester) async {
+      debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
+
       final List<MethodCall> platformCallLog = <MethodCall>[];
 
       SystemChannels.platform.setMockMethodCallHandler((MethodCall methodCall) async {
@@ -276,11 +295,14 @@ void main() {
         platformCallLog.last,
         isMethodCall('HapticFeedback.vibrate', arguments: 'HapticFeedbackType.mediumImpact'),
       );
-    }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+      debugDefaultTargetPlatformOverride = null;
+    });
 
     testWidgets(
       'refreshing task keeps the sliver expanded forever until done',
       (WidgetTester tester) async {
+        debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
+
         await tester.pumpWidget(
           Directionality(
             textDirection: TextDirection.ltr,
@@ -348,11 +370,15 @@ void main() {
           60.0, // Default value.
         ));
         verifyNoMoreInteractions(mockHelper);
-    }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+
+        debugDefaultTargetPlatformOverride = null;
+      },
+    );
 
     testWidgets(
       'refreshing task keeps the sliver expanded forever until completes with error',
       (WidgetTester tester) async {
+        debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
         final FlutterError error = FlutterError('Oops');
         double errorCount = 0;
 
@@ -434,9 +460,14 @@ void main() {
             errorCount++;
           },
         );
-    }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+
+        debugDefaultTargetPlatformOverride = null;
+      },
+    );
 
     testWidgets('expanded refreshing sliver scrolls normally', (WidgetTester tester) async {
+      debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
+
       refreshIndicator = const Center(child: Text('-1'));
 
       await tester.pumpWidget(
@@ -510,9 +541,13 @@ void main() {
         tester.getRect(find.widgetWithText(Center, '0')),
         const Rect.fromLTRB(0.0, 60.0, 800.0, 260.0),
       );
-    }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+
+      debugDefaultTargetPlatformOverride = null;
+    });
 
     testWidgets('expanded refreshing sliver goes away when done', (WidgetTester tester) async {
+      debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
+
       refreshIndicator = const Center(child: Text('-1'));
 
       await tester.pumpWidget(
@@ -581,9 +616,13 @@ void main() {
         tester.getRect(find.widgetWithText(Center, '0')),
         const Rect.fromLTRB(0.0, 0.0, 800.0, 200.0),
       );
-    }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+
+      debugDefaultTargetPlatformOverride = null;
+    });
 
     testWidgets('builder still called when sliver snapped back more than 90%', (WidgetTester tester) async {
+      debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
+
       refreshIndicator = const Center(child: Text('-1'));
 
       await tester.pumpWidget(
@@ -665,11 +704,15 @@ void main() {
         60.0, // Default value.
       ));
       expect(find.text('-1'), findsOneWidget);
-    }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+
+      debugDefaultTargetPlatformOverride = null;
+    });
 
     testWidgets(
       'retracting sliver during done cannot be pulled to refresh again until fully retracted',
       (WidgetTester tester) async {
+        debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
+
         refreshIndicator = const Center(child: Text('-1'));
 
         await tester.pumpWidget(
@@ -748,12 +791,17 @@ void main() {
           40.0,
           100.0, // Default value.
           60.0, // Default value.
-      ));
+        ));
-    }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+
+        debugDefaultTargetPlatformOverride = null;
+      },
+    );
 
     testWidgets(
       'sliver held in overscroll when task finishes completes normally',
       (WidgetTester tester) async {
+        debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
+
         refreshIndicator = const Center(child: Text('-1'));
 
         await tester.pumpWidget(
@@ -800,7 +848,10 @@ void main() {
           tester.getRect(find.widgetWithText(Center, '0')),
           const Rect.fromLTRB(0.0, 0.0, 800.0, 200.0),
         );
-    }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+
+        debugDefaultTargetPlatformOverride = null;
+      },
+    );
 
     testWidgets(
       'sliver scrolled away when task completes properly removes itself',
@@ -810,6 +861,8 @@ void main() {
           // the indicator can be scrolled away while refreshing.
           return;
         }
+        debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
+
         refreshIndicator = const Center(child: Text('-1'));
 
         await tester.pumpWidget(
@@ -887,11 +940,16 @@ void main() {
           tester.getRect(find.widgetWithText(Center, '0')),
           const Rect.fromLTRB(0.0, 0.0, 800.0, 200.0),
         );
-    }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+
+        debugDefaultTargetPlatformOverride = null;
+      },
+    );
 
     testWidgets(
       "don't do anything unless it can be overscrolled at the start of the list",
       (WidgetTester tester) async {
+        debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
+
         refreshIndicator = const Center(child: Text('-1'));
 
         await tester.pumpWidget(
@@ -915,11 +973,16 @@ void main() {
         await tester.fling(find.byType(Container).first, const Offset(0.0, -200.0), 3000.0);
 
         verifyNoMoreInteractions(mockHelper);
-    }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+
+        debugDefaultTargetPlatformOverride = null;
+      },
+    );
 
     testWidgets(
       'without an onRefresh, builder is called with arm for one frame then sliver goes away',
       (WidgetTester tester) async {
+        debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
+
         refreshIndicator = const Center(child: Text('-1'));
 
         await tester.pumpWidget(
@@ -961,7 +1024,10 @@ void main() {
           tester.getRect(find.widgetWithText(Center, '0')),
           const Rect.fromLTRB(0.0, 0.0, 800.0, 200.0),
         );
-    }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+
+        debugDefaultTargetPlatformOverride = null;
+      },
+    );
 
     testWidgets('Should not crash when dragged', (WidgetTester tester) async {
       await tester.pumpWidget(
@@ -985,11 +1051,13 @@ void main() {
       await tester.pump();
 
       expect(tester.takeException(), isNull);
-    }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+    });
   };
 
   final VoidCallback stateMachineTestGroup = () {
     testWidgets('starts in inactive state', (WidgetTester tester) async {
+      debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
+
       await tester.pumpWidget(
         Directionality(
           textDirection: TextDirection.ltr,
@@ -1008,9 +1076,13 @@ void main() {
         CupertinoSliverRefreshControl.state(tester.element(find.byType(LayoutBuilder, skipOffstage: false))),
         RefreshIndicatorMode.inactive,
       );
-    }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+
+      debugDefaultTargetPlatformOverride = null;
+    });
 
     testWidgets('goes to drag and returns to inactive in a small drag', (WidgetTester tester) async {
+      debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
+
       await tester.pumpWidget(
         Directionality(
           textDirection: TextDirection.ltr,
@@ -1039,9 +1111,13 @@ void main() {
         CupertinoSliverRefreshControl.state(tester.element(find.byType(LayoutBuilder, skipOffstage: false))),
         RefreshIndicatorMode.inactive,
       );
-    }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+
+      debugDefaultTargetPlatformOverride = null;
+    });
 
     testWidgets('goes to armed the frame it passes the threshold', (WidgetTester tester) async {
+      debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
+
       await tester.pumpWidget(
         Directionality(
           textDirection: TextDirection.ltr,
@@ -1071,11 +1147,15 @@ void main() {
         CupertinoSliverRefreshControl.state(tester.element(find.byType(LayoutBuilder))),
         RefreshIndicatorMode.armed,
       );
-    }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+
+      debugDefaultTargetPlatformOverride = null;
+    });
 
     testWidgets(
       'goes to refresh the frame it crossed back the refresh threshold',
       (WidgetTester tester) async {
+        debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
+
         await tester.pumpWidget(
           Directionality(
             textDirection: TextDirection.ltr,
@@ -1111,11 +1191,16 @@ void main() {
           CupertinoSliverRefreshControl.state(tester.element(find.byType(LayoutBuilder))),
           RefreshIndicatorMode.refresh,
         );
-    }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+
+        debugDefaultTargetPlatformOverride = null;
+      },
+    );
 
     testWidgets(
       'goes to done internally as soon as the task finishes',
       (WidgetTester tester) async {
+        debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
+
         await tester.pumpWidget(
           Directionality(
             textDirection: TextDirection.ltr,
@@ -1158,11 +1243,16 @@ void main() {
           CupertinoSliverRefreshControl.state(tester.element(find.byType(LayoutBuilder))),
           RefreshIndicatorMode.done,
         );
-    }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+
+        debugDefaultTargetPlatformOverride = null;
+      },
+    );
 
     testWidgets(
       'goes back to inactive when retracting back past 10% of arming distance',
       (WidgetTester tester) async {
+        debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
+
         await tester.pumpWidget(
           Directionality(
             textDirection: TextDirection.ltr,
@@ -1216,11 +1306,16 @@ void main() {
           CupertinoSliverRefreshControl.state(tester.element(find.byType(LayoutBuilder))),
           RefreshIndicatorMode.inactive,
         );
-    }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+
+        debugDefaultTargetPlatformOverride = null;
+      },
+    );
 
     testWidgets(
       'goes back to inactive if already scrolled away when task completes',
       (WidgetTester tester) async {
+        debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
+
         await tester.pumpWidget(
           Directionality(
             textDirection: TextDirection.ltr,
@@ -1275,11 +1370,16 @@ void main() {
           tester.getTopLeft(find.widgetWithText(Container, '0')).dy,
           moreOrLessEquals(-145.0332383665717),
         );
-    }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+
+        debugDefaultTargetPlatformOverride = null;
+      },
+    );
 
     testWidgets(
       "don't have to build any indicators or occupy space during refresh",
       (WidgetTester tester) async {
+        debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
+
         refreshIndicator = const Center(child: Text('-1'));
 
         await tester.pumpWidget(
@@ -1325,7 +1425,10 @@ void main() {
           CupertinoSliverRefreshControl.state(tester.element(find.byType(LayoutBuilder, skipOffstage: false))),
           RefreshIndicatorMode.inactive,
         );
-    }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+
+        debugDefaultTargetPlatformOverride = null;
+      },
+    );
 
     testWidgets('buildSimpleRefreshIndicator dark mode', (WidgetTester tester) async {
       const CupertinoDynamicColor color = CupertinoColors.inactiveGray;

packages/flutter/test/cupertino/route_test.dart

@@ -3,14 +3,11 @@
 // found in the LICENSE file.
 
 import 'package:flutter/cupertino.dart';
-import 'package:flutter/foundation.dart';
 import 'package:flutter/rendering.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 import 'package:mockito/mockito.dart';
 
-import '../widgets/semantics_tester.dart';
-
 void main() {
   MockNavigatorObserver navigatorObserver;
 
@@ -1055,75 +1052,6 @@ void main() {
     expect(rootObserver.dialogCount, 0);
     expect(nestedObserver.dialogCount, 1);
   });
-
-  testWidgets('showCupertinoModalPopup does not allow for semantics dismiss by default', (WidgetTester tester) async {
-    debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
-    final SemanticsTester semantics = SemanticsTester(tester);
-    await tester.pumpWidget(CupertinoApp(
-      home: Navigator(
-        onGenerateRoute: (RouteSettings settings) {
-          return PageRouteBuilder<dynamic>(
-            pageBuilder: (BuildContext context, Animation<double> _, Animation<double> __) {
-              return GestureDetector(
-                onTap: () async {
-                  await showCupertinoModalPopup<void>(
-                    context: context,
-                    builder: (BuildContext context) => const SizedBox(),
-                  );
-                },
-                child: const Text('tap'),
-              );
-            },
-          );
-        },
-      ),
-    ));
-
-    // Push the route.
-    await tester.tap(find.text('tap'));
-    await tester.pumpAndSettle();
-
-    expect(semantics, isNot(includesNodeWith(
-      actions: <SemanticsAction>[SemanticsAction.tap],
-      label: 'Dismiss',
-    )));
-    debugDefaultTargetPlatformOverride = null;
-  });
-
-  testWidgets('showCupertinoModalPopup allows for semantics dismiss when set', (WidgetTester tester) async {
-    debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
-    final SemanticsTester semantics = SemanticsTester(tester);
-    await tester.pumpWidget(CupertinoApp(
-      home: Navigator(
-        onGenerateRoute: (RouteSettings settings) {
-          return PageRouteBuilder<dynamic>(
-            pageBuilder: (BuildContext context, Animation<double> _, Animation<double> __) {
-              return GestureDetector(
-                onTap: () async {
-                  await showCupertinoModalPopup<void>(
-                    context: context,
-                    semanticsDismissible: true,
-                    builder: (BuildContext context) => const SizedBox(),
-                  );
-                },
-                child: const Text('tap'),
-              );
-            },
-          );
-        },
-      ),
-    ));
-
-    // Push the route.
-    await tester.tap(find.text('tap'));
-    await tester.pumpAndSettle();
-
-    expect(semantics, includesNodeWith(
-      actions: <SemanticsAction>[SemanticsAction.tap],
-      label: 'Dismiss',
-    ));
-    debugDefaultTargetPlatformOverride = null;
-  });
 }
 
 class MockNavigatorObserver extends Mock implements NavigatorObserver {}

packages/flutter/test/cupertino/switch_test.dart

@@ -43,6 +43,7 @@ void main() {
   });
 
   testWidgets('Switch emits light haptic vibration on tap', (WidgetTester tester) async {
+    debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
     final Key switchKey = UniqueKey();
     bool value = false;
 
@@ -79,9 +80,11 @@ void main() {
 
     expect(log, hasLength(1));
     expect(log.single, isMethodCall('HapticFeedback.vibrate', arguments: 'HapticFeedbackType.lightImpact'));
-  }, variant: TargetPlatformVariant.only(TargetPlatform.iOS));
+    debugDefaultTargetPlatformOverride = null;
+  });
 
   testWidgets('Using other widgets that rebuild the switch will not cause vibrations', (WidgetTester tester) async {
+    debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
     final Key switchKey = UniqueKey();
     final Key switchKey2 = UniqueKey();
     bool value = false;
@@ -149,9 +152,11 @@ void main() {
 
     expect(log, hasLength(4));
     expect(log[3], isMethodCall('HapticFeedback.vibrate', arguments: 'HapticFeedbackType.lightImpact'));
-  }, variant: TargetPlatformVariant.only(TargetPlatform.iOS));
+    debugDefaultTargetPlatformOverride = null;
+  });
 
   testWidgets('Haptic vibration triggers on drag', (WidgetTester tester) async {
+    debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
     bool value = false;
     final List<MethodCall> log = <MethodCall>[];
 
@@ -186,9 +191,11 @@ void main() {
 
     expect(log, hasLength(1));
     expect(log[0], isMethodCall('HapticFeedback.vibrate', arguments: 'HapticFeedbackType.lightImpact'));
-  }, variant: TargetPlatformVariant.only(TargetPlatform.iOS));
+    debugDefaultTargetPlatformOverride = null;
+  });
 
   testWidgets('No haptic vibration triggers from a programmatic value change', (WidgetTester tester) async {
+    debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
     final Key switchKey = UniqueKey();
     bool value = false;
 
@@ -237,7 +244,8 @@ void main() {
     await tester.pump();
 
     expect(log, hasLength(0));
-  }, variant: TargetPlatformVariant.only(TargetPlatform.iOS));
+    debugDefaultTargetPlatformOverride = null;
+  });
 
   testWidgets('Switch can drag (LTR)', (WidgetTester tester) async {
     bool value = false;

packages/flutter/test/cupertino/text_field_test.dart

@@ -425,7 +425,9 @@ void main() {
     expect(editableText.cursorOffset, const Offset(-2.0 / 3.0, 0));
   });
 
-  testWidgets('Cursor animates', (WidgetTester tester) async {
+  testWidgets('Cursor animates on iOS', (WidgetTester tester) async {
+    debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
+
     await tester.pumpWidget(
       const CupertinoApp(
         home: CupertinoTextField(),
@@ -457,9 +459,13 @@ void main() {
     await tester.pump(const Duration(milliseconds: 50));
 
     expect(renderEditable.cursorColor.alpha, 0);
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS, TargetPlatform.macOS }));
 
-  testWidgets('Cursor radius is 2.0', (WidgetTester tester) async {
+    debugDefaultTargetPlatformOverride = null;
+  });
+
+  testWidgets('Cursor radius is 2.0 on iOS', (WidgetTester tester) async {
+    debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
+
     await tester.pumpWidget(
       const CupertinoApp(
         home: CupertinoTextField(),
@@ -470,7 +476,9 @@ void main() {
     final RenderEditable renderEditable = editableTextState.renderEditable;
 
     expect(renderEditable.cursorRadius, const Radius.circular(2.0));
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS, TargetPlatform.macOS }));
+
+    debugDefaultTargetPlatformOverride = null;
+  });
 
   testWidgets('Cupertino cursor android golden', (WidgetTester tester) async {
     final Widget widget = CupertinoApp(
@@ -499,7 +507,9 @@ void main() {
     );
   });
 
-  testWidgets('Cupertino cursor golden', (WidgetTester tester) async {
+  testWidgets('Cupertino cursor iOS golden', (WidgetTester tester) async {
+    debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
+
     final Widget widget = CupertinoApp(
       home: Center(
         child: RepaintBoundary(
@@ -520,13 +530,12 @@ void main() {
     await tester.tapAt(textOffsetToPosition(tester, testValue.length));
     await tester.pumpAndSettle();
 
+    debugDefaultTargetPlatformOverride = null;
     await expectLater(
       find.byKey(const ValueKey<int>(1)),
-      matchesGoldenFile(
+      matchesGoldenFile('text_field_cursor_test.cupertino.1.png'),
-        'text_field_cursor_test.cupertino_${describeEnum(debugDefaultTargetPlatformOverride).toLowerCase()}.1.png',
-      ),
     );
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+  });
 
   testWidgets(
     'can control text content via controller',
@@ -2937,7 +2946,8 @@ void main() {
     expect(editableText.cursorColor.value, 0x87654321);
   });
 
-  testWidgets('shows selection handles', (WidgetTester tester) async {
+  testWidgets('iOS shows selection handles', (WidgetTester tester) async {
+    debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
     const String testText = 'lorem ipsum';
     final TextEditingController controller = TextEditingController(text: testText);
 
@@ -2967,7 +2977,9 @@ void main() {
 
     expect(left.opacity.value, equals(1.0));
     expect(right.opacity.value, equals(1.0));
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+
+    debugDefaultTargetPlatformOverride = null;
+  });
 
   testWidgets('when CupertinoTextField would be blocked by keyboard, it is shown with enough space for the selection handle', (WidgetTester tester) async {
     final ScrollController scrollController = ScrollController();

packages/flutter/test/flutter_test_alternative.dart

@@ -11,7 +11,7 @@ import 'package:test_api/test_api.dart' as test_package show TypeMatcher; // ign
 export 'package:test_api/test_api.dart' hide TypeMatcher, isInstanceOf; // ignore: deprecated_member_use
 
 /// A matcher that compares the type of the actual value to the type argument T.
-test_package.TypeMatcher<T> isInstanceOf<T>() => isA<T>();
+Matcher isInstanceOf<T>() => test_package.TypeMatcher<T>();
 
 /// Whether we are running in a web browser.
 const bool isBrowser = identical(0, 0.0);

packages/flutter/test/foundation/consolidate_response_test.dart

@@ -110,7 +110,8 @@ void main() {
       });
       when(response.contentLength).thenReturn(-1);
 
-      expect(consolidateHttpClientResponseBytes(response), throwsException);
+      expect(consolidateHttpClientResponseBytes(response),
+          throwsA(isInstanceOf<Exception>()));
     });
 
     test('Propagates error to Future return value if onBytesReceived throws', () async {

packages/flutter/test/foundation/isolates_test.dart

@@ -27,9 +27,9 @@ Future<int> test2Async(int value) async {
 void main() {
   test('compute()', () async {
     expect(await compute(test1, 0), 1);
-    expect(compute(test2, 0), throwsException);
+    expect(compute(test2, 0), throwsA(isInstanceOf<Exception>()));
 
     expect(await compute(test1Async, 0), 1);
-    expect(compute(test2Async, 0), throwsException);
+    expect(compute(test2Async, 0), throwsA(isInstanceOf<Exception>()));
   });
 }

packages/flutter/test/foundation/service_extensions_test.dart

@@ -489,51 +489,43 @@ void main() {
     extensionChangedEvent = extensionChangedEvents.last;
     expect(extensionChangedEvent['extension'], 'ext.flutter.platformOverride');
     expect(extensionChangedEvent['value'], 'iOS');
-    result = await hasReassemble(binding.testExtension('platformOverride', <String, String>{'value': 'macOS'}));
-    expect(result, <String, String>{'value': 'macOS'});
-    expect(binding.reassembled, 2);
-    expect(defaultTargetPlatform, TargetPlatform.macOS);
-    expect(extensionChangedEvents.length, 2);
-    extensionChangedEvent = extensionChangedEvents.last;
-    expect(extensionChangedEvent['extension'], 'ext.flutter.platformOverride');
-    expect(extensionChangedEvent['value'], 'macOS');
     result = await hasReassemble(binding.testExtension('platformOverride', <String, String>{'value': 'android'}));
     expect(result, <String, String>{'value': 'android'});
-    expect(binding.reassembled, 3);
+    expect(binding.reassembled, 2);
     expect(defaultTargetPlatform, TargetPlatform.android);
-    expect(extensionChangedEvents.length, 3);
+    expect(extensionChangedEvents.length, 2);
     extensionChangedEvent = extensionChangedEvents.last;
     expect(extensionChangedEvent['extension'], 'ext.flutter.platformOverride');
     expect(extensionChangedEvent['value'], 'android');
     result = await hasReassemble(binding.testExtension('platformOverride', <String, String>{'value': 'fuchsia'}));
     expect(result, <String, String>{'value': 'fuchsia'});
-    expect(binding.reassembled, 4);
+    expect(binding.reassembled, 3);
     expect(defaultTargetPlatform, TargetPlatform.fuchsia);
-    expect(extensionChangedEvents.length, 4);
+    expect(extensionChangedEvents.length, 3);
     extensionChangedEvent = extensionChangedEvents.last;
     expect(extensionChangedEvent['extension'], 'ext.flutter.platformOverride');
     expect(extensionChangedEvent['value'], 'fuchsia');
     result = await hasReassemble(binding.testExtension('platformOverride', <String, String>{'value': 'default'}));
     expect(result, <String, String>{'value': 'android'});
-    expect(binding.reassembled, 5);
+    expect(binding.reassembled, 4);
     expect(defaultTargetPlatform, TargetPlatform.android);
-    expect(extensionChangedEvents.length, 5);
+    expect(extensionChangedEvents.length, 4);
     extensionChangedEvent = extensionChangedEvents.last;
     expect(extensionChangedEvent['extension'], 'ext.flutter.platformOverride');
     expect(extensionChangedEvent['value'], 'android');
     result = await hasReassemble(binding.testExtension('platformOverride', <String, String>{'value': 'iOS'}));
     expect(result, <String, String>{'value': 'iOS'});
-    expect(binding.reassembled, 6);
+    expect(binding.reassembled, 5);
     expect(defaultTargetPlatform, TargetPlatform.iOS);
-    expect(extensionChangedEvents.length, 6);
+    expect(extensionChangedEvents.length, 5);
     extensionChangedEvent = extensionChangedEvents.last;
     expect(extensionChangedEvent['extension'], 'ext.flutter.platformOverride');
     expect(extensionChangedEvent['value'], 'iOS');
     result = await hasReassemble(binding.testExtension('platformOverride', <String, String>{'value': 'bogus'}));
     expect(result, <String, String>{'value': 'android'});
-    expect(binding.reassembled, 7);
+    expect(binding.reassembled, 6);
     expect(defaultTargetPlatform, TargetPlatform.android);
-    expect(extensionChangedEvents.length, 7);
+    expect(extensionChangedEvents.length, 6);
     extensionChangedEvent = extensionChangedEvents.last;
     expect(extensionChangedEvent['extension'], 'ext.flutter.platformOverride');
     expect(extensionChangedEvent['value'], 'android');

packages/flutter/test/material/app_bar_test.dart

@@ -2,7 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/rendering.dart';
 import 'package:flutter/services.dart';
@@ -84,68 +83,66 @@ void main() {
     Size size = tester.getSize(title);
     expect(center.dx, lessThan(400 - size.width / 2.0));
 
-    for (final TargetPlatform platform in <TargetPlatform>[TargetPlatform.iOS, TargetPlatform.macOS]) {
+    // Clear the widget tree to avoid animating between Android and iOS.
-      // Clear the widget tree to avoid animating between platforms.
+    await tester.pumpWidget(Container(key: UniqueKey()));
-      await tester.pumpWidget(Container(key: UniqueKey()));
 
-      await tester.pumpWidget(
+    await tester.pumpWidget(
-        MaterialApp(
+      MaterialApp(
-          theme: ThemeData(platform: platform),
+        theme: ThemeData(platform: TargetPlatform.iOS),
-          home: Scaffold(
+        home: Scaffold(
-            appBar: AppBar(
+          appBar: AppBar(
-              title: const Text('X'),
+            title: const Text('X'),
-            ),
           ),
         ),
-      );
+      ),
+    );
 
-      center = tester.getCenter(title);
+    center = tester.getCenter(title);
-      size = tester.getSize(title);
+    size = tester.getSize(title);
-      expect(center.dx, greaterThan(400 - size.width / 2.0), reason: 'on ${describeEnum(platform)}');
+    expect(center.dx, greaterThan(400 - size.width / 2.0));
-      expect(center.dx, lessThan(400 + size.width / 2.0), reason: 'on ${describeEnum(platform)}');
+    expect(center.dx, lessThan(400 + size.width / 2.0));
 
-      // One action is still centered.
+    // One action is still centered.
 
-      await tester.pumpWidget(
+    await tester.pumpWidget(
-        MaterialApp(
+      MaterialApp(
-          theme: ThemeData(platform: platform),
+        theme: ThemeData(platform: TargetPlatform.iOS),
-          home: Scaffold(
+        home: Scaffold(
-            appBar: AppBar(
+          appBar: AppBar(
-              title: const Text('X'),
+            title: const Text('X'),
-              actions: const <Widget>[
+            actions: const <Widget>[
-                Icon(Icons.thumb_up),
+              Icon(Icons.thumb_up),
-              ],
+            ],
-            ),
           ),
         ),
-      );
+      ),
+    );
 
-      center = tester.getCenter(title);
+    center = tester.getCenter(title);
-      size = tester.getSize(title);
+    size = tester.getSize(title);
-      expect(center.dx, greaterThan(400 - size.width / 2.0), reason: 'on ${describeEnum(platform)}');
+    expect(center.dx, greaterThan(400 - size.width / 2.0));
-      expect(center.dx, lessThan(400 + size.width / 2.0), reason: 'on ${describeEnum(platform)}');
+    expect(center.dx, lessThan(400 + size.width / 2.0));
 
-      // Two actions is left aligned again.
+    // Two actions is left aligned again.
 
-      await tester.pumpWidget(
+    await tester.pumpWidget(
-        MaterialApp(
+      MaterialApp(
-          theme: ThemeData(platform: platform),
+        theme: ThemeData(platform: TargetPlatform.iOS),
-          home: Scaffold(
+        home: Scaffold(
-            appBar: AppBar(
+          appBar: AppBar(
-              title: const Text('X'),
+            title: const Text('X'),
-              actions: const <Widget>[
+            actions: const <Widget>[
-                Icon(Icons.thumb_up),
+              Icon(Icons.thumb_up),
-                Icon(Icons.thumb_up),
+              Icon(Icons.thumb_up),
-              ],
+            ],
-            ),
           ),
         ),
-      );
+      ),
+    );
 
-      center = tester.getCenter(title);
+    center = tester.getCenter(title);
-      size = tester.getSize(title);
+    size = tester.getSize(title);
-      expect(center.dx, lessThan(400 - size.width / 2.0), reason: 'on ${describeEnum(platform)}');
+    expect(center.dx, lessThan(400 - size.width / 2.0));
-    }
   });
 
   testWidgets('AppBar centerTitle:true centers on Android', (WidgetTester tester) async {

packages/flutter/test/material/app_builder_test.dart

@@ -17,7 +17,7 @@ void main() {
         log.add('build');
         expect(Theme.of(context).primaryColor, Colors.green);
         expect(Directionality.of(context), TextDirection.ltr);
-        expect(child, isA<Navigator>());
+        expect(child, isInstanceOf<Navigator>());
         return const Placeholder();
       },
     );

packages/flutter/test/material/app_test.dart

@@ -322,7 +322,7 @@ void main() {
       ),
     );
     final dynamic exception = tester.takeException();
-    expect(exception, isA<String>());
+    expect(exception is String, isTrue);
     expect(exception.startsWith('Could not navigate to initial route.'), isTrue);
     expect(find.text('route "/"'), findsOneWidget);
     expect(find.text('route "/a"'), findsNothing);
@@ -474,7 +474,7 @@ void main() {
       color: const Color(0xFF112233),
       home: const Placeholder(),
     ));
-    expect(key.currentState, isA<NavigatorState>());
+    expect(key.currentState, isInstanceOf<NavigatorState>());
     await tester.pumpWidget(const MaterialApp(
       color: Color(0xFF112233),
       home: Placeholder(),
@@ -485,7 +485,7 @@ void main() {
       color: const Color(0xFF112233),
       home: const Placeholder(),
     ));
-    expect(key.currentState, isA<NavigatorState>());
+    expect(key.currentState, isInstanceOf<NavigatorState>());
   });
 
   testWidgets('Has default material and cupertino localizations', (WidgetTester tester) async {

packages/flutter/test/material/back_button_test.dart

@@ -66,37 +66,30 @@ void main() {
   });
 
   testWidgets('BackButton icon', (WidgetTester tester) async {
-    final Key androidKey = UniqueKey();
     final Key iOSKey = UniqueKey();
-    final Key macOSKey = UniqueKey();
+    final Key androidKey = UniqueKey();
+
 
     await tester.pumpWidget(
       MaterialApp(
         home: Column(
           children: <Widget>[
-            Theme(
-              data: ThemeData(platform: TargetPlatform.android),
-              child: BackButtonIcon(key: androidKey),
-            ),
             Theme(
               data: ThemeData(platform: TargetPlatform.iOS),
               child: BackButtonIcon(key: iOSKey),
             ),
             Theme(
-              data: ThemeData(platform: TargetPlatform.macOS),
+              data: ThemeData(platform: TargetPlatform.android),
-              child: BackButtonIcon(key: macOSKey),
+              child: BackButtonIcon(key: androidKey),
             ),
           ],
         ),
       ),
     );
 
-    final Icon androidIcon = tester.widget(find.descendant(of: find.byKey(androidKey), matching: find.byType(Icon)));
     final Icon iOSIcon = tester.widget(find.descendant(of: find.byKey(iOSKey), matching: find.byType(Icon)));
-    final Icon macOSIcon = tester.widget(find.descendant(of: find.byKey(macOSKey), matching: find.byType(Icon)));
+    final Icon androidIcon = tester.widget(find.descendant(of: find.byKey(androidKey), matching: find.byType(Icon)));
-    expect(iOSIcon.icon == androidIcon.icon, isFalse);
+    expect(iOSIcon == androidIcon, false);
-    expect(macOSIcon.icon == androidIcon.icon, isFalse);
-    expect(macOSIcon.icon == iOSIcon.icon, isTrue);
   });
 
   testWidgets('BackButton semantics', (WidgetTester tester) async {

packages/flutter/test/material/bottom_navigation_bar_test.dart

@@ -1449,7 +1449,7 @@ void main() {
           ),
         ),
       );
-    }, throwsAssertionError);
+    }, throwsA(isInstanceOf<AssertionError>()));
   });
 
   testWidgets(

packages/flutter/test/material/chip_theme_test.dart

@@ -184,7 +184,7 @@ void main() {
     expect(lightTheme.secondarySelectedColor, equals(customColor1.withAlpha(0x3d)));
     expect(lightTheme.labelPadding, equals(const EdgeInsets.symmetric(horizontal: 8.0)));
     expect(lightTheme.padding, equals(const EdgeInsets.all(4.0)));
-    expect(lightTheme.shape, isA<StadiumBorder>());
+    expect(lightTheme.shape, equals(isInstanceOf<StadiumBorder>()));
     expect(lightTheme.labelStyle.color, equals(Colors.black.withAlpha(0xde)));
     expect(lightTheme.secondaryLabelStyle.color, equals(customColor1.withAlpha(0xde)));
     expect(lightTheme.brightness, equals(Brightness.light));
@@ -202,7 +202,7 @@ void main() {
     expect(darkTheme.secondarySelectedColor, equals(customColor1.withAlpha(0x3d)));
     expect(darkTheme.labelPadding, equals(const EdgeInsets.symmetric(horizontal: 8.0)));
     expect(darkTheme.padding, equals(const EdgeInsets.all(4.0)));
-    expect(darkTheme.shape, isA<StadiumBorder>());
+    expect(darkTheme.shape, equals(isInstanceOf<StadiumBorder>()));
     expect(darkTheme.labelStyle.color, equals(Colors.white.withAlpha(0xde)));
     expect(darkTheme.secondaryLabelStyle.color, equals(customColor1.withAlpha(0xde)));
     expect(darkTheme.brightness, equals(Brightness.dark));
@@ -220,7 +220,7 @@ void main() {
     expect(customTheme.secondarySelectedColor, equals(customColor2.withAlpha(0x3d)));
     expect(customTheme.labelPadding, equals(const EdgeInsets.symmetric(horizontal: 8.0)));
     expect(customTheme.padding, equals(const EdgeInsets.all(4.0)));
-    expect(customTheme.shape, isA<StadiumBorder>());
+    expect(customTheme.shape, equals(isInstanceOf<StadiumBorder>()));
     expect(customTheme.labelStyle.color, equals(customColor1.withAlpha(0xde)));
     expect(customTheme.secondaryLabelStyle.color, equals(customColor2.withAlpha(0xde)));
     expect(customTheme.brightness, equals(Brightness.light));
@@ -263,7 +263,7 @@ void main() {
     expect(lerp.selectedShadowColor, equals(middleGrey));
     expect(lerp.labelPadding, equals(const EdgeInsets.all(4.0)));
     expect(lerp.padding, equals(const EdgeInsets.all(3.0)));
-    expect(lerp.shape, isA<StadiumBorder>());
+    expect(lerp.shape, equals(isInstanceOf<StadiumBorder>()));
     expect(lerp.labelStyle.color, equals(middleGrey.withAlpha(0xde)));
     expect(lerp.secondaryLabelStyle.color, equals(middleGrey.withAlpha(0xde)));
     expect(lerp.brightness, equals(Brightness.light));
@@ -283,7 +283,7 @@ void main() {
     expect(lerpANull25.selectedShadowColor, equals(Colors.white.withAlpha(0x40)));
     expect(lerpANull25.labelPadding, equals(const EdgeInsets.only(left: 0.0, top: 2.0, right: 0.0, bottom: 2.0)));
     expect(lerpANull25.padding, equals(const EdgeInsets.all(0.5)));
-    expect(lerpANull25.shape, isA<StadiumBorder>());
+    expect(lerpANull25.shape, equals(isInstanceOf<StadiumBorder>()));
     expect(lerpANull25.labelStyle.color, equals(Colors.black.withAlpha(0x38)));
     expect(lerpANull25.secondaryLabelStyle.color, equals(Colors.white.withAlpha(0x38)));
     expect(lerpANull25.brightness, equals(Brightness.light));
@@ -301,7 +301,7 @@ void main() {
     expect(lerpANull75.selectedShadowColor, equals(Colors.white.withAlpha(0xbf)));
     expect(lerpANull75.labelPadding, equals(const EdgeInsets.only(left: 0.0, top: 6.0, right: 0.0, bottom: 6.0)));
     expect(lerpANull75.padding, equals(const EdgeInsets.all(1.5)));
-    expect(lerpANull75.shape, isA<StadiumBorder>());
+    expect(lerpANull75.shape, equals(isInstanceOf<StadiumBorder>()));
     expect(lerpANull75.labelStyle.color, equals(Colors.black.withAlpha(0xa7)));
     expect(lerpANull75.secondaryLabelStyle.color, equals(Colors.white.withAlpha(0xa7)));
     expect(lerpANull75.brightness, equals(Brightness.light));
@@ -319,7 +319,7 @@ void main() {
     expect(lerpBNull25.selectedShadowColor, equals(Colors.black.withAlpha(0xbf)));
     expect(lerpBNull25.labelPadding, equals(const EdgeInsets.only(left: 6.0, top: 0.0, right: 6.0, bottom: 0.0)));
     expect(lerpBNull25.padding, equals(const EdgeInsets.all(3.0)));
-    expect(lerpBNull25.shape, isA<StadiumBorder>());
+    expect(lerpBNull25.shape, equals(isInstanceOf<StadiumBorder>()));
     expect(lerpBNull25.labelStyle.color, equals(Colors.white.withAlpha(0xa7)));
     expect(lerpBNull25.secondaryLabelStyle.color, equals(Colors.black.withAlpha(0xa7)));
     expect(lerpBNull25.brightness, equals(Brightness.dark));
@@ -337,7 +337,7 @@ void main() {
     expect(lerpBNull75.selectedShadowColor, equals(Colors.black.withAlpha(0x40)));
     expect(lerpBNull75.labelPadding, equals(const EdgeInsets.only(left: 2.0, top: 0.0, right: 2.0, bottom: 0.0)));
     expect(lerpBNull75.padding, equals(const EdgeInsets.all(1.0)));
-    expect(lerpBNull75.shape, isA<StadiumBorder>());
+    expect(lerpBNull75.shape, equals(isInstanceOf<StadiumBorder>()));
     expect(lerpBNull75.labelStyle.color, equals(Colors.white.withAlpha(0x38)));
     expect(lerpBNull75.secondaryLabelStyle.color, equals(Colors.black.withAlpha(0x38)));
     expect(lerpBNull75.brightness, equals(Brightness.light));

packages/flutter/test/material/debug_test.dart

@@ -22,8 +22,8 @@ void main() {
         'Card, Dialog, Drawer, or Scaffold.\n',
       ),
     );
-    expect(error.diagnostics[3], isA<DiagnosticsProperty<Element>>());
+    expect(error.diagnostics[3], isInstanceOf<DiagnosticsProperty<Element>>());
-    expect(error.diagnostics[4], isA<DiagnosticsBlock>());
+    expect(error.diagnostics[4], isInstanceOf<DiagnosticsBlock>());
     expect(error.toStringDeep(),
       'FlutterError\n'
       '   No Material widget found.\n'
@@ -60,8 +60,8 @@ void main() {
         'add a Localization widget with a MaterialLocalizations delegate.\n',
       ),
     );
-    expect(error.diagnostics[4], isA<DiagnosticsProperty<Element>>());
+    expect(error.diagnostics[4], isInstanceOf<DiagnosticsProperty<Element>>());
-    expect(error.diagnostics[5], isA<DiagnosticsBlock>());
+    expect(error.diagnostics[5], isInstanceOf<DiagnosticsBlock>());
     expect(error.toStringDeep(),
       'FlutterError\n'
       '   No MaterialLocalizations found.\n'
@@ -97,8 +97,8 @@ void main() {
     expect(exception, isFlutterError);
     final FlutterError error = exception as FlutterError;
     expect(error.diagnostics.length, 5);
-    expect(error.diagnostics[2], isA<DiagnosticsProperty<Element>>());
+    expect(error.diagnostics[2], isInstanceOf<DiagnosticsProperty<Element>>());
-    expect(error.diagnostics[3], isA<DiagnosticsBlock>());
+    expect(error.diagnostics[3], isInstanceOf<DiagnosticsBlock>());
     expect(error.diagnostics[4].level, DiagnosticLevel.hint);
     expect(
       error.diagnostics[4].toStringDeep(),

packages/flutter/test/material/drawer_test.dart

@@ -57,8 +57,9 @@ void main() {
     expect(find.text('header'), findsOneWidget);
   });
 
-  testWidgets('Drawer dismiss barrier has label', (WidgetTester tester) async {
+  testWidgets('Drawer dismiss barrier has label on iOS', (WidgetTester tester) async {
     final SemanticsTester semantics = SemanticsTester(tester);
+    debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
     await tester.pumpWidget(
       const MaterialApp(
         home: Scaffold(
@@ -79,9 +80,10 @@ void main() {
     ));
 
     semantics.dispose();
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+    debugDefaultTargetPlatformOverride = null;
+  });
 
-  testWidgets('Drawer dismiss barrier has no label', (WidgetTester tester) async {
+  testWidgets('Drawer dismiss barrier has no label on Android', (WidgetTester tester) async {
     final SemanticsTester semantics = SemanticsTester(tester);
     await tester.pumpWidget(
       const MaterialApp(
@@ -103,7 +105,7 @@ void main() {
     )));
 
     semantics.dispose();
-  }, variant: TargetPlatformVariant.only(TargetPlatform.android));
+  });
 
   testWidgets('Scaffold drawerScrimColor', (WidgetTester tester) async {
     // The scrim is a Container within a Semantics node labeled "Dismiss",

packages/flutter/test/material/expansion_tile_test.dart

@@ -58,6 +58,7 @@ void main() {
 
     await tester.pumpWidget(MaterialApp(
       theme: ThemeData(
+        platform: TargetPlatform.iOS,
         dividerColor: _dividerColor,
       ),
       home: Material(
@@ -153,7 +154,7 @@ void main() {
     expect(collapsedContainerDecoration.color, Colors.transparent);
     expect(collapsedContainerDecoration.border.top.color, _dividerColor);
     expect(collapsedContainerDecoration.border.bottom.color, _dividerColor);
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+  });
 
   testWidgets('ListTileTheme', (WidgetTester tester) async {
     final Key expandedTitleKey = UniqueKey();
@@ -164,6 +165,7 @@ void main() {
     await tester.pumpWidget(
       MaterialApp(
         theme: ThemeData(
+          platform: TargetPlatform.iOS,
           accentColor: _accentColor,
           unselectedWidgetColor: _unselectedWidgetColor,
           textTheme: const TextTheme(subhead: TextStyle(color: _headerColor)),
@@ -212,7 +214,7 @@ void main() {
     expect(textColor(collapsedTitleKey), _accentColor);
     expect(iconColor(expandedIconKey), _unselectedWidgetColor);
     expect(iconColor(collapsedIconKey), _accentColor);
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+  });
 
   testWidgets('ExpansionTile subtitle', (WidgetTester tester) async {
     await tester.pumpWidget(

packages/flutter/test/material/flexible_space_bar_collapse_mode_test.dart

@@ -2,7 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_test/flutter_test.dart';
 
@@ -11,10 +10,10 @@ const double expandedAppbarHeight = 250.0;
 final Key appbarContainerKey = UniqueKey();
 
 void main() {
-  testWidgets('FlexibleSpaceBar collapse mode none', (WidgetTester tester) async {
+  testWidgets('FlexibleSpaceBar collapse mode none on Android', (WidgetTester tester) async {
     await tester.pumpWidget(
       MaterialApp(
-        theme: ThemeData(platform: debugDefaultTargetPlatformOverride),
+        theme: ThemeData(platform: TargetPlatform.android),
         home: Scaffold(
           body: CustomScrollView(
             key: blockKey,
@@ -47,12 +46,50 @@ void main() {
 
     expect(topBeforeScroll.dy, equals(0.0));
     expect(topAfterScroll.dy, equals(0.0));
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.android, TargetPlatform.iOS,  TargetPlatform.macOS }));
+  });
 
-  testWidgets('FlexibleSpaceBar collapse mode pin', (WidgetTester tester) async {
+  testWidgets('FlexibleSpaceBar collapse mode none on IOS', (WidgetTester tester) async {
     await tester.pumpWidget(
       MaterialApp(
-        theme: ThemeData(platform: debugDefaultTargetPlatformOverride),
+        theme: ThemeData(platform: TargetPlatform.iOS),
+        home: Scaffold(
+          body: CustomScrollView(
+            key: blockKey,
+            slivers: <Widget>[
+              SliverAppBar(
+                expandedHeight: expandedAppbarHeight,
+                pinned: true,
+                flexibleSpace: FlexibleSpaceBar(
+                  background: Container(
+                    key: appbarContainerKey,
+                  ),
+                  collapseMode: CollapseMode.none,
+                ),
+              ),
+              SliverToBoxAdapter(
+                child: Container(
+                  height: 10000.0,
+                ),
+              ),
+            ],
+          ),
+        ),
+      ),
+    );
+
+    final Finder appbarContainer = find.byKey(appbarContainerKey);
+    final Offset topBeforeScroll = tester.getTopLeft(appbarContainer);
+    await slowDrag(tester, blockKey, const Offset(0.0, -100.0));
+    final Offset topAfterScroll = tester.getTopLeft(appbarContainer);
+
+    expect(topBeforeScroll.dy, equals(0.0));
+    expect(topAfterScroll.dy, equals(0.0));
+  });
+
+  testWidgets('FlexibleSpaceBar collapse mode pin on Android', (WidgetTester tester) async {
+    await tester.pumpWidget(
+      MaterialApp(
+        theme: ThemeData(platform: TargetPlatform.android),
         home: Scaffold(
           body: CustomScrollView(
             key: blockKey,
@@ -85,12 +122,52 @@ void main() {
 
     expect(topBeforeScroll.dy, equals(0.0));
     expect(topAfterScroll.dy, equals(-100.0));
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.android, TargetPlatform.iOS,  TargetPlatform.macOS }));
+  });
 
-  testWidgets('FlexibleSpaceBar collapse mode parallax', (WidgetTester tester) async {
+  testWidgets('FlexibleSpaceBar collapse mode pin on IOS', (WidgetTester tester) async {
     await tester.pumpWidget(
       MaterialApp(
-        theme: ThemeData(platform: debugDefaultTargetPlatformOverride),
+        theme: ThemeData(platform: TargetPlatform.iOS),
+        home: Scaffold(
+          body: CustomScrollView(
+            key: blockKey,
+            slivers: <Widget>[
+              SliverAppBar(
+                expandedHeight: expandedAppbarHeight,
+                pinned: true,
+                flexibleSpace: FlexibleSpaceBar(
+                  background: Container(
+                    key: appbarContainerKey,
+                  ),
+                  collapseMode: CollapseMode.pin,
+                ),
+              ),
+              SliverToBoxAdapter(
+                child: Container(
+                  height: 10000.0,
+                ),
+              ),
+            ],
+          ),
+        ),
+      ),
+    );
+
+    final Finder appbarContainer = find.byKey(appbarContainerKey);
+    final Offset topBeforeScroll = tester.getTopLeft(appbarContainer);
+    await slowDrag(tester, blockKey, const Offset(0.0, -100.0));
+    final Offset topAfterScroll = tester.getTopLeft(appbarContainer);
+
+    expect(topBeforeScroll.dy, equals(0.0));
+    expect(topAfterScroll.dy, equals(-100.0));
+  });
+
+
+
+  testWidgets('FlexibleSpaceBar collapse mode parallax on Android', (WidgetTester tester) async {
+    await tester.pumpWidget(
+      MaterialApp(
+        theme: ThemeData(platform: TargetPlatform.android),
         home: Scaffold(
           body: CustomScrollView(
             key: blockKey,
@@ -124,7 +201,46 @@ void main() {
     expect(topBeforeScroll.dy, equals(0.0));
     expect(topAfterScroll.dy, lessThan(10.0));
     expect(topAfterScroll.dy, greaterThan(-50.0));
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.android, TargetPlatform.iOS,  TargetPlatform.macOS }));
+  });
+
+  testWidgets('FlexibleSpaceBar collapse mode parallax on IOS', (WidgetTester tester) async {
+    await tester.pumpWidget(
+      MaterialApp(
+        theme: ThemeData(platform: TargetPlatform.iOS),
+        home: Scaffold(
+          body: CustomScrollView(
+            key: blockKey,
+            slivers: <Widget>[
+              SliverAppBar(
+                expandedHeight: expandedAppbarHeight,
+                pinned: true,
+                flexibleSpace: FlexibleSpaceBar(
+                  background: Container(
+                    key: appbarContainerKey,
+                  ),
+                  collapseMode: CollapseMode.parallax,
+                ),
+              ),
+              SliverToBoxAdapter(
+                child: Container(
+                  height: 10000.0,
+                ),
+              ),
+            ],
+          ),
+        ),
+      ),
+    );
+
+    final Finder appbarContainer = find.byKey(appbarContainerKey);
+    final Offset topBeforeScroll = tester.getTopLeft(appbarContainer);
+    await slowDrag(tester, blockKey, const Offset(0.0, -100.0));
+    final Offset topAfterScroll = tester.getTopLeft(appbarContainer);
+
+    expect(topBeforeScroll.dy, equals(0.0));
+    expect(topAfterScroll.dy, lessThan(10.0));
+    expect(topAfterScroll.dy, greaterThan(-50.0));
+  });
 }
 
 Future<void> slowDrag(WidgetTester tester, Key widget, Offset offset) async {

packages/flutter/test/material/flexible_space_bar_test.dart

@@ -25,28 +25,26 @@ void main() {
     Size size = tester.getSize(title);
     expect(center.dx, lessThan(400.0 - size.width / 2.0));
 
-    for (final TargetPlatform platform in <TargetPlatform>[ TargetPlatform.iOS, TargetPlatform.macOS ]) {
+    // Clear the widget tree to avoid animating between Android and iOS.
-      // Clear the widget tree to avoid animating between platforms.
+    await tester.pumpWidget(Container(key: UniqueKey()));
-      await tester.pumpWidget(Container(key: UniqueKey()));
 
-      await tester.pumpWidget(
+    await tester.pumpWidget(
-        MaterialApp(
+      MaterialApp(
-          theme: ThemeData(platform: platform),
+        theme: ThemeData(platform: TargetPlatform.iOS),
-          home: Scaffold(
+        home: Scaffold(
-            appBar: AppBar(
+          appBar: AppBar(
-              flexibleSpace: const FlexibleSpaceBar(
+            flexibleSpace: const FlexibleSpaceBar(
-                title: Text('X'),
+              title: Text('X'),
-              ),
             ),
           ),
         ),
-      );
+      ),
+    );
 
-      center = tester.getCenter(title);
+    center = tester.getCenter(title);
-      size = tester.getSize(title);
+    size = tester.getSize(title);
-      expect(center.dx, greaterThan(400.0 - size.width / 2.0));
+    expect(center.dx, greaterThan(400.0 - size.width / 2.0));
-      expect(center.dx, lessThan(400.0 + size.width / 2.0));
+    expect(center.dx, lessThan(400.0 + size.width / 2.0));
-    }
   });
 
   testWidgets('FlexibleSpaceBarSettings provides settings to a FlexibleSpaceBar', (WidgetTester tester) async {
@@ -156,15 +154,6 @@ void main() {
     await tester.pumpWidget(buildFrame(TargetPlatform.iOS, false));
     expect(getTitleBottomLeft(), const Offset(72.0, 16.0));
 
-    // Clear the widget tree to avoid animating between iOS and macOS.
-    await tester.pumpWidget(Container(key: UniqueKey()));
-
-    await tester.pumpWidget(buildFrame(TargetPlatform.macOS, null));
-    expect(getTitleBottomLeft(), const Offset(390.0, 16.0));
-
-    await tester.pumpWidget(buildFrame(TargetPlatform.macOS, false));
-    expect(getTitleBottomLeft(), const Offset(72.0, 16.0));
-
   }, skip: isBrowser);
 
   testWidgets('FlexibleSpaceBar test titlePadding override', (WidgetTester tester) async {
@@ -206,15 +195,6 @@ void main() {
 
     await tester.pumpWidget(buildFrame(TargetPlatform.iOS, false));
     expect(getTitleBottomLeft(), Offset.zero);
-
-    // Clear the widget tree to avoid animating between iOS and macOS.
-    await tester.pumpWidget(Container(key: UniqueKey()));
-
-    await tester.pumpWidget(buildFrame(TargetPlatform.macOS, null));
-    expect(getTitleBottomLeft(), const Offset(390.0, 0.0));
-
-    await tester.pumpWidget(buildFrame(TargetPlatform.macOS, false));
-    expect(getTitleBottomLeft(), Offset.zero);
   }, skip: isBrowser);
 }
 

packages/flutter/test/material/outline_button_test.dart

@@ -1047,7 +1047,7 @@ PhysicalModelLayer _findPhysicalLayer(Element element) {
     object = object.parent as RenderObject;
   }
   expect(object.debugLayer, isNotNull);
-  expect(object.debugLayer.firstChild, isA<PhysicalModelLayer>());
+  expect(object.debugLayer.firstChild, isInstanceOf<PhysicalModelLayer>());
   final PhysicalModelLayer layer = object.debugLayer.firstChild as PhysicalModelLayer;
   final Layer child = layer.firstChild;
   return child is PhysicalModelLayer ? child : layer;

packages/flutter/test/material/page_test.dart

@@ -2,7 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/cupertino.dart' show CupertinoPageRoute;
 import 'package:flutter/rendering.dart';
@@ -11,9 +10,10 @@ import 'package:flutter_test/flutter_test.dart';
 import '../rendering/mock_canvas.dart';
 
 void main() {
-  testWidgets('test page transition', (WidgetTester tester) async {
+  testWidgets('test Android page transition', (WidgetTester tester) async {
     await tester.pumpWidget(
       MaterialApp(
+        theme: ThemeData(platform: TargetPlatform.android),
         home: const Material(child: Text('Page 1')),
         routes: <String, WidgetBuilder>{
           '/next': (BuildContext context) {
@@ -66,12 +66,13 @@ void main() {
 
     expect(find.text('Page 1'), isOnstage);
     expect(find.text('Page 2'), findsNothing);
-  }, variant: TargetPlatformVariant.only(TargetPlatform.android));
+  });
 
-  testWidgets('test page transition', (WidgetTester tester) async {
+  testWidgets('test iOS page transition', (WidgetTester tester) async {
     final Key page2Key = UniqueKey();
     await tester.pumpWidget(
       MaterialApp(
+        theme: ThemeData(platform: TargetPlatform.iOS),
         home: const Material(child: Text('Page 1')),
         routes: <String, WidgetBuilder>{
           '/next': (BuildContext context) {
@@ -144,12 +145,13 @@ void main() {
 
     // Page 1 is back where it started.
     expect(widget1InitialTopLeft == widget1TransientTopLeft, true);
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS, TargetPlatform.macOS }));
+  });
 
-  testWidgets('test fullscreen dialog transition', (WidgetTester tester) async {
+  testWidgets('test iOS fullscreen dialog transition', (WidgetTester tester) async {
     await tester.pumpWidget(
-      const MaterialApp(
+      MaterialApp(
-        home: Material(child: Text('Page 1')),
+        theme: ThemeData(platform: TargetPlatform.iOS),
+        home: const Material(child: Text('Page 1')),
       ),
     );
 
@@ -204,11 +206,12 @@ void main() {
 
     // Page 1 is back where it started.
     expect(widget1InitialTopLeft == widget1TransientTopLeft, true);
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS, TargetPlatform.macOS }));
+  });
 
   testWidgets('test no back gesture on Android', (WidgetTester tester) async {
     await tester.pumpWidget(
       MaterialApp(
+        theme: ThemeData(platform: TargetPlatform.android),
         home: const Scaffold(body: Text('Page 1')),
         routes: <String, WidgetBuilder>{
           '/next': (BuildContext context) {
@@ -234,11 +237,12 @@ void main() {
 
     // Page 2 didn't move
     expect(tester.getTopLeft(find.text('Page 2')), Offset.zero);
-  }, variant: TargetPlatformVariant.only(TargetPlatform.android));
+  });
 
-  testWidgets('test back gesture', (WidgetTester tester) async {
+  testWidgets('test back gesture on iOS', (WidgetTester tester) async {
     await tester.pumpWidget(
       MaterialApp(
+        theme: ThemeData(platform: TargetPlatform.iOS),
         home: const Scaffold(body: Text('Page 1')),
         routes: <String, WidgetBuilder>{
           '/next': (BuildContext context) {
@@ -275,7 +279,7 @@ void main() {
     await tester.pump();
 
     expect(tester.getTopLeft(find.text('Page 2')), const Offset(100.0, 0.0));
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS, TargetPlatform.macOS }));
+  });
 
   testWidgets('back gesture while OS changes', (WidgetTester tester) async {
     final Map<String, WidgetBuilder> routes = <String, WidgetBuilder>{
@@ -342,36 +346,13 @@ void main() {
     expect(await tester.pumpAndSettle(const Duration(minutes: 1)), 3);
     expect(find.text('PUSH'), findsOneWidget);
     expect(find.text('HELLO'), findsNothing);
-
-    await tester.pumpWidget(
-      MaterialApp(
-        theme: ThemeData(platform: TargetPlatform.macOS),
-        routes: routes,
-      ),
-    );
-    await tester.tap(find.text('PUSH'));
-    expect(await tester.pumpAndSettle(const Duration(minutes: 1)), 2);
-    expect(find.text('PUSH'), findsNothing);
-    expect(find.text('HELLO'), findsOneWidget);
-    final Offset helloPosition5 = tester.getCenter(find.text('HELLO'));
-    await gesture.down(const Offset(2.5, 300.0));
-    await tester.pump(const Duration(milliseconds: 20));
-    await gesture.moveBy(const Offset(100.0, 0.0));
-    expect(find.text('PUSH'), findsNothing);
-    expect(find.text('HELLO'), findsOneWidget);
-    await tester.pump(const Duration(milliseconds: 20));
-    expect(find.text('PUSH'), findsOneWidget);
-    expect(find.text('HELLO'), findsOneWidget);
-    final Offset helloPosition6 = tester.getCenter(find.text('HELLO'));
-    expect(helloPosition5.dx, lessThan(helloPosition6.dx));
-    expect(helloPosition5.dy, helloPosition6.dy);
-    expect(Theme.of(tester.element(find.text('HELLO'))).platform, TargetPlatform.macOS);
   });
 
-  testWidgets('test no back gesture on fullscreen dialogs', (WidgetTester tester) async {
+  testWidgets('test no back gesture on iOS fullscreen dialogs', (WidgetTester tester) async {
     await tester.pumpWidget(
-      const MaterialApp(
+      MaterialApp(
-        home: Scaffold(body: Text('Page 1')),
+        theme: ThemeData(platform: TargetPlatform.iOS),
+        home: const Scaffold(body: Text('Page 1')),
       ),
     );
 
@@ -396,7 +377,7 @@ void main() {
 
     // Page 2 didn't move
     expect(tester.getTopLeft(find.text('Page 2')), Offset.zero);
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+  });
 
   testWidgets('test adaptable transitions switch during execution', (WidgetTester tester) async {
     await tester.pumpWidget(
@@ -436,6 +417,7 @@ void main() {
     // Re-pump the same app but with iOS instead of Android.
     await tester.pumpWidget(
       MaterialApp(
+        theme: ThemeData(platform: TargetPlatform.iOS),
         home: const Material(child: Text('Page 1')),
         routes: <String, WidgetBuilder>{
           '/next': (BuildContext context) {
@@ -470,7 +452,7 @@ void main() {
 
     // Page 1 is back where it started.
     expect(widget1InitialTopLeft == widget1TransientTopLeft, true);
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+  });
 
   testWidgets('throws when builder returns null', (WidgetTester tester) async {
     await tester.pumpWidget(const MaterialApp(
@@ -488,7 +470,7 @@ void main() {
     await tester.pumpAndSettle();
     // An exception should've been thrown because the `builder` returned null.
     final dynamic exception = tester.takeException();
-    expect(exception, isFlutterError);
+    expect(exception, isInstanceOf<FlutterError>());
     expect(exception.toStringDeep(), equalsIgnoringHashCodes(
       'FlutterError\n'
       '   The builder for route "broken" returned null.\n'
@@ -496,9 +478,10 @@ void main() {
     ));
   });
 
-  testWidgets('test edge swipe then drop back at starting point works', (WidgetTester tester) async {
+  testWidgets('test iOS edge swipe then drop back at starting point works', (WidgetTester tester) async {
     await tester.pumpWidget(
       MaterialApp(
+        theme: ThemeData(platform: TargetPlatform.iOS),
         onGenerateRoute: (RouteSettings settings) {
           return MaterialPageRoute<void>(
             settings: settings,
@@ -529,11 +512,12 @@ void main() {
 
     expect(find.text('Page 1'), findsNothing);
     expect(find.text('Page 2'), isOnstage);
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+  });
 
-  testWidgets('test edge swipe then drop back at ending point works', (WidgetTester tester) async {
+  testWidgets('test iOS edge swipe then drop back at ending point works', (WidgetTester tester) async {
     await tester.pumpWidget(
       MaterialApp(
+        theme: ThemeData(platform: TargetPlatform.iOS),
         onGenerateRoute: (RouteSettings settings) {
           return MaterialPageRoute<void>(
             settings: settings,
@@ -562,7 +546,7 @@ void main() {
 
     expect(find.text('Page 1'), isOnstage);
     expect(find.text('Page 2'), findsNothing);
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+  });
 
   testWidgets('Back swipe dismiss interrupted by route push', (WidgetTester tester) async {
     // Regression test for https://github.com/flutter/flutter/issues/28728
@@ -570,6 +554,7 @@ void main() {
 
     await tester.pumpWidget(
       MaterialApp(
+        theme: ThemeData(platform: TargetPlatform.iOS),
         home: Scaffold(
           key: scaffoldKey,
           body: Center(
@@ -657,7 +642,7 @@ void main() {
     await tester.pumpAndSettle();
     expect(find.text('route'), findsOneWidget);
     expect(find.text('push'), findsNothing);
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+  });
 
   testWidgets('During back swipe the route ignores input', (WidgetTester tester) async {
     // Regression test for https://github.com/flutter/flutter/issues/39989
@@ -669,6 +654,7 @@ void main() {
 
     await tester.pumpWidget(
       MaterialApp(
+        theme: ThemeData(platform: TargetPlatform.iOS),
         home: Scaffold(
           key: homeScaffoldKey,
           body: GestureDetector(
@@ -727,7 +713,7 @@ void main() {
     await tester.pumpAndSettle();
     expect(tester.getTopLeft(find.byKey(pageScaffoldKey)), const Offset(400, 0));
     expect(tester.getTopLeft(find.byKey(homeScaffoldKey)).dx, lessThan(0));
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+  });
 
   testWidgets('After a pop caused by a back-swipe, input reaches the exposed route', (WidgetTester tester) async {
     // Regression test for https://github.com/flutter/flutter/issues/41024
@@ -739,6 +725,7 @@ void main() {
 
     await tester.pumpWidget(
       MaterialApp(
+        theme: ThemeData(platform: TargetPlatform.iOS),
         home: Scaffold(
           key: homeScaffoldKey,
           body: GestureDetector(
@@ -798,9 +785,9 @@ void main() {
     await tester.tap(find.byKey(homeScaffoldKey));
     expect(homeTapCount, 2);
     expect(pageTapCount, 1);
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+  });
 
-  testWidgets('A MaterialPageRoute should slide out with CupertinoPageTransition when a compatible PageRoute is pushed on top of it', (WidgetTester tester) async {
+  testWidgets('On iOS, a MaterialPageRoute should slide out with CupertinoPageTransition when a compatible PageRoute is pushed on top of it', (WidgetTester tester) async {
     // Regression test for https://github.com/flutter/flutter/issues/44864.
 
     await tester.pumpWidget(
@@ -826,5 +813,5 @@ void main() {
     // Title of the first route slides to the left.
     expect(titleInitialTopLeft.dy, equals(titleTransientTopLeft.dy));
     expect(titleInitialTopLeft.dx, greaterThan(titleTransientTopLeft.dx));
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+  });
 }

packages/flutter/test/material/page_transitions_theme_test.dart

@@ -3,7 +3,6 @@
 // found in the LICENSE file.
 
 import 'package:flutter/cupertino.dart';
-import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_test/flutter_test.dart';
 
@@ -12,16 +11,11 @@ void main() {
     await tester.pumpWidget(const MaterialApp(home: Text('home')));
     final PageTransitionsTheme theme = Theme.of(tester.element(find.text('home'))).pageTransitionsTheme;
     expect(theme.builders, isNotNull);
-    for (final TargetPlatform platform in TargetPlatform.values) {
+    expect(theme.builders[TargetPlatform.android], isNotNull);
-      if (platform == TargetPlatform.fuchsia) {
+    expect(theme.builders[TargetPlatform.iOS], isNotNull);
-        // No builder on Fuchsia.
-        continue;
-      }
-      expect(theme.builders[platform], isNotNull, reason: 'theme builder for $platform is null');
-    }
   });
 
-  testWidgets('Default PageTranstionsTheme builds a CupertionPageTransition', (WidgetTester tester) async {
+  testWidgets('Default PageTranstionsTheme builds a CupertionPageTransition for iOS', (WidgetTester tester) async {
     final Map<String, WidgetBuilder> routes = <String, WidgetBuilder>{
       '/': (BuildContext context) => Material(
         child: FlatButton(
@@ -34,18 +28,19 @@ void main() {
 
     await tester.pumpWidget(
       MaterialApp(
+        theme: ThemeData(platform: TargetPlatform.iOS),
         routes: routes,
       ),
     );
 
-    expect(Theme.of(tester.element(find.text('push'))).platform, debugDefaultTargetPlatformOverride);
+    expect(Theme.of(tester.element(find.text('push'))).platform, TargetPlatform.iOS);
     expect(find.byType(CupertinoPageTransition), findsOneWidget);
 
     await tester.tap(find.text('push'));
     await tester.pumpAndSettle();
     expect(find.text('page b'), findsOneWidget);
     expect(find.byType(CupertinoPageTransition), findsOneWidget);
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+  });
 
   testWidgets('Default PageTranstionsTheme builds a _FadeUpwardsPageTransition for android', (WidgetTester tester) async {
     final Map<String, WidgetBuilder> routes = <String, WidgetBuilder>{
@@ -60,6 +55,7 @@ void main() {
 
     await tester.pumpWidget(
       MaterialApp(
+        theme: ThemeData(platform: TargetPlatform.android),
         routes: routes,
       ),
     );
@@ -71,16 +67,16 @@ void main() {
       );
     }
 
-    expect(Theme.of(tester.element(find.text('push'))).platform, debugDefaultTargetPlatformOverride);
+    expect(Theme.of(tester.element(find.text('push'))).platform, TargetPlatform.android);
     expect(findFadeUpwardsPageTransition(), findsOneWidget);
 
     await tester.tap(find.text('push'));
     await tester.pumpAndSettle();
     expect(find.text('page b'), findsOneWidget);
     expect(findFadeUpwardsPageTransition(), findsOneWidget);
-  }, variant: TargetPlatformVariant.only(TargetPlatform.android));
+  });
 
-  testWidgets('pageTranstionsTheme override builds a _OpenUpwardsPageTransition', (WidgetTester tester) async {
+  testWidgets('pageTranstionsTheme override builds a _OpenUpwardsPageTransition for android', (WidgetTester tester) async {
     final Map<String, WidgetBuilder> routes = <String, WidgetBuilder>{
       '/': (BuildContext context) => Material(
         child: FlatButton(
@@ -94,6 +90,7 @@ void main() {
     await tester.pumpWidget(
       MaterialApp(
         theme: ThemeData(
+          platform: TargetPlatform.android,
           pageTransitionsTheme: const PageTransitionsTheme(
             builders: <TargetPlatform, PageTransitionsBuilder>{
               TargetPlatform.android: OpenUpwardsPageTransitionsBuilder(), // creates a _OpenUpwardsPageTransition
@@ -111,16 +108,16 @@ void main() {
       );
     }
 
-    expect(Theme.of(tester.element(find.text('push'))).platform, debugDefaultTargetPlatformOverride);
+    expect(Theme.of(tester.element(find.text('push'))).platform, TargetPlatform.android);
     expect(findOpenUpwardsPageTransition(), findsOneWidget);
 
     await tester.tap(find.text('push'));
     await tester.pumpAndSettle();
     expect(find.text('page b'), findsOneWidget);
     expect(findOpenUpwardsPageTransition(), findsOneWidget);
-  }, variant: TargetPlatformVariant.only(TargetPlatform.android));
+  });
 
-  testWidgets('pageTranstionsTheme override builds a _ZoomPageTransition', (WidgetTester tester) async {
+  testWidgets('pageTranstionsTheme override builds a _ZoomPageTransition for android', (WidgetTester tester) async {
     final Map<String, WidgetBuilder> routes = <String, WidgetBuilder>{
       '/': (BuildContext context) => Material(
         child: FlatButton(
@@ -134,6 +131,7 @@ void main() {
     await tester.pumpWidget(
       MaterialApp(
         theme: ThemeData(
+          platform: TargetPlatform.android,
           pageTransitionsTheme: const PageTransitionsTheme(
             builders: <TargetPlatform, PageTransitionsBuilder>{
               TargetPlatform.android: ZoomPageTransitionsBuilder(), // creates a _ZoomPageTransition
@@ -151,12 +149,12 @@ void main() {
       );
     }
 
-    expect(Theme.of(tester.element(find.text('push'))).platform, debugDefaultTargetPlatformOverride);
+    expect(Theme.of(tester.element(find.text('push'))).platform, TargetPlatform.android);
     expect(findZoomPageTransition(), findsOneWidget);
 
     await tester.tap(find.text('push'));
     await tester.pumpAndSettle();
     expect(find.text('page b'), findsOneWidget);
     expect(findZoomPageTransition(), findsOneWidget);
-  }, variant: TargetPlatformVariant.only(TargetPlatform.android));
+  });
 }

packages/flutter/test/material/paginated_data_table_test.dart

@@ -164,7 +164,7 @@ void main() {
 
     // the column overflows because we're forcing it to 600 pixels high
     final dynamic exception = tester.takeException();
-    expect(exception, isFlutterError);
+    expect(exception, isInstanceOf<FlutterError>());
     expect(exception.diagnostics.first.level, DiagnosticLevel.summary);
     expect(exception.diagnostics.first.toString(), startsWith('A RenderFlex overflowed by '));
 
@@ -252,7 +252,7 @@ void main() {
     ));
     // the column overflows because we're forcing it to 600 pixels high
     final dynamic exception = tester.takeException();
-    expect(exception, isFlutterError);
+    expect(exception, isInstanceOf<FlutterError>());
     expect(exception.diagnostics.first.level, DiagnosticLevel.summary);
     expect(exception.diagnostics.first.toString(), contains('A RenderFlex overflowed by'));
 

packages/flutter/test/material/popup_menu_test.dart

@@ -325,12 +325,6 @@ void main() {
 
     expect(find.byIcon(Icons.more_vert), findsNothing);
     expect(find.byIcon(Icons.more_horiz), findsOneWidget);
-
-    await tester.pumpWidget(build(TargetPlatform.macOS));
-    await tester.pumpAndSettle(); // Run theme change animation.
-
-    expect(find.byIcon(Icons.more_vert), findsNothing);
-    expect(find.byIcon(Icons.more_horiz), findsOneWidget);
   });
 
   group('PopupMenuButton with Icon', () {
@@ -351,7 +345,7 @@ void main() {
             icon: const Icon(Icons.view_carousel),
             itemBuilder: simplePopupMenuItemBuilder,
         );
-      }, throwsAssertionError);
+      }, throwsA(isInstanceOf<AssertionError>()));
     });
 
     testWidgets('PopupMenuButton creates IconButton when given an icon', (WidgetTester tester) async {

packages/flutter/test/material/refresh_indicator_test.dart

@@ -387,7 +387,8 @@ void main() {
     expect(tester.takeException(), isFlutterError);
   });
 
-  testWidgets('Refresh starts while scroll view moves back to 0.0 after overscroll', (WidgetTester tester) async {
+  testWidgets('Refresh starts while scroll view moves back to 0.0 after overscroll on iOS', (WidgetTester tester) async {
+    debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
     refreshCalled = false;
     double lastScrollOffset;
     final ScrollController controller = ScrollController();
@@ -419,5 +420,7 @@ void main() {
     expect(controller.offset, greaterThan(lastScrollOffset));
     expect(controller.offset, lessThan(0.0));
     expect(refreshCalled, isTrue);
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+
+    debugDefaultTargetPlatformOverride = null;
+  });
 }

packages/flutter/test/material/scaffold_test.dart

@@ -320,17 +320,17 @@ void main() {
     );
   }
 
-  testWidgets('Tapping the status bar scrolls to top', (WidgetTester tester) async {
+  testWidgets('Tapping the status bar scrolls to top on iOS', (WidgetTester tester) async {
-    await tester.pumpWidget(_buildStatusBarTestApp(debugDefaultTargetPlatformOverride));
+    await tester.pumpWidget(_buildStatusBarTestApp(TargetPlatform.iOS));
     final ScrollableState scrollable = tester.state(find.byType(Scrollable));
     scrollable.position.jumpTo(500.0);
     expect(scrollable.position.pixels, equals(500.0));
     await tester.tapAt(const Offset(100.0, 10.0));
     await tester.pumpAndSettle();
     expect(scrollable.position.pixels, equals(0.0));
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+  });
 
-  testWidgets('Tapping the status bar does not scroll to top', (WidgetTester tester) async {
+  testWidgets('Tapping the status bar does not scroll to top on Android', (WidgetTester tester) async {
     await tester.pumpWidget(_buildStatusBarTestApp(TargetPlatform.android));
     final ScrollableState scrollable = tester.state(find.byType(Scrollable));
     scrollable.position.jumpTo(500.0);
@@ -339,7 +339,7 @@ void main() {
     await tester.pump();
     await tester.pump(const Duration(seconds: 1));
     expect(scrollable.position.pixels, equals(500.0));
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.android }));
+  });
 
   testWidgets('Bottom sheet cannot overlap app bar', (WidgetTester tester) async {
     final Key sheetKey = UniqueKey();
@@ -506,7 +506,7 @@ void main() {
   });
 
   group('back arrow', () {
-    Future<void> expectBackIcon(WidgetTester tester, IconData expectedIcon) async {
+    Future<void> expectBackIcon(WidgetTester tester, TargetPlatform platform, IconData expectedIcon) async {
       final GlobalKey rootKey = GlobalKey();
       final Map<String, WidgetBuilder> routes = <String, WidgetBuilder>{
         '/': (_) => Container(key: rootKey, child: const Text('Home')),
@@ -515,7 +515,9 @@ void main() {
             body: const Text('Scaffold'),
         ),
       };
-      await tester.pumpWidget(MaterialApp(routes: routes));
+      await tester.pumpWidget(
+        MaterialApp(theme: ThemeData(platform: platform), routes: routes)
+      );
 
       Navigator.pushNamed(rootKey.currentContext, '/scaffold');
       await tester.pump();
@@ -525,20 +527,24 @@ void main() {
       expect(icon.icon, expectedIcon);
     }
 
-    testWidgets('Back arrow uses correct default', (WidgetTester tester) async {
+    testWidgets('Back arrow uses correct default on Android', (WidgetTester tester) async {
-      await expectBackIcon(tester, Icons.arrow_back);
+      await expectBackIcon(tester, TargetPlatform.android, Icons.arrow_back);
-    }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.android, TargetPlatform.fuchsia }));
+    });
 
-    testWidgets('Back arrow uses correct default', (WidgetTester tester) async {
+    testWidgets('Back arrow uses correct default on Fuchsia', (WidgetTester tester) async {
-      await expectBackIcon(tester, Icons.arrow_back_ios);
+      await expectBackIcon(tester, TargetPlatform.fuchsia, Icons.arrow_back);
-    }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+    });
+
+    testWidgets('Back arrow uses correct default on iOS', (WidgetTester tester) async {
+      await expectBackIcon(tester, TargetPlatform.iOS, Icons.arrow_back_ios);
+    });
   });
 
   group('close button', () {
-    Future<void> expectCloseIcon(WidgetTester tester, PageRoute<void> routeBuilder(), String type) async {
+    Future<void> expectCloseIcon(WidgetTester tester, TargetPlatform platform, IconData expectedIcon, PageRoute<void> routeBuilder()) async {
-      const IconData expectedIcon = Icons.close;
       await tester.pumpWidget(
         MaterialApp(
+          theme: ThemeData(platform: platform),
           home: Scaffold(appBar: AppBar(), body: const Text('Page 1')),
         ),
       );
@@ -549,8 +555,8 @@ void main() {
       await tester.pump(const Duration(seconds: 1));
 
       final Icon icon = tester.widget(find.byType(Icon));
-      expect(icon.icon, expectedIcon, reason: "didn't find close icon for $type");
+      expect(icon.icon, expectedIcon);
-      expect(find.byType(CloseButton), findsOneWidget, reason: "didn't find close button for $type");
+      expect(find.byType(CloseButton), findsOneWidget);
     }
 
     PageRoute<void> materialRouteBuilder() {
@@ -580,17 +586,41 @@ void main() {
       );
     }
 
-    testWidgets('Close button shows correctly', (WidgetTester tester) async {
+    testWidgets('Close button shows correctly on Android', (WidgetTester tester) async {
-      await expectCloseIcon(tester, materialRouteBuilder, 'materialRouteBuilder');
+      await expectCloseIcon(tester, TargetPlatform.android, Icons.close, materialRouteBuilder);
-    }, variant: TargetPlatformVariant.all());
+    });
 
-    testWidgets('Close button shows correctly with PageRouteBuilder', (WidgetTester tester) async {
+    testWidgets('Close button shows correctly on Fuchsia', (WidgetTester tester) async {
-      await expectCloseIcon(tester, pageRouteBuilder, 'pageRouteBuilder');
+      await expectCloseIcon(tester, TargetPlatform.fuchsia, Icons.close, materialRouteBuilder);
-    }, variant: TargetPlatformVariant.all());
+    });
 
-    testWidgets('Close button shows correctly with custom page route', (WidgetTester tester) async {
+    testWidgets('Close button shows correctly on iOS', (WidgetTester tester) async {
-      await expectCloseIcon(tester, customPageRouteBuilder, 'customPageRouteBuilder');
+      await expectCloseIcon(tester, TargetPlatform.iOS, Icons.close, materialRouteBuilder);
-    }, variant: TargetPlatformVariant.all());
+    });
+
+    testWidgets('Close button shows correctly with PageRouteBuilder on Android', (WidgetTester tester) async {
+      await expectCloseIcon(tester, TargetPlatform.android, Icons.close, pageRouteBuilder);
+    });
+
+    testWidgets('Close button shows correctly with PageRouteBuilder on Fuchsia', (WidgetTester tester) async {
+      await expectCloseIcon(tester, TargetPlatform.fuchsia, Icons.close, pageRouteBuilder);
+    });
+
+    testWidgets('Close button shows correctly with PageRouteBuilder on iOS', (WidgetTester tester) async {
+      await expectCloseIcon(tester, TargetPlatform.iOS, Icons.close, pageRouteBuilder);
+    });
+
+    testWidgets('Close button shows correctly with custom page route on Android', (WidgetTester tester) async {
+      await expectCloseIcon(tester, TargetPlatform.android, Icons.close, customPageRouteBuilder);
+    });
+
+    testWidgets('Close button shows correctly with custom page route on Fuchsia', (WidgetTester tester) async {
+      await expectCloseIcon(tester, TargetPlatform.fuchsia, Icons.close, customPageRouteBuilder);
+    });
+
+    testWidgets('Close button shows correctly with custom page route on iOS', (WidgetTester tester) async {
+      await expectCloseIcon(tester, TargetPlatform.iOS, Icons.close, customPageRouteBuilder);
+    });
   });
 
   group('body size', () {
@@ -1794,7 +1824,7 @@ void main() {
           'the ScaffoldState rather than using the Scaffold.of() function.\n',
         ),
       );
-      expect(error.diagnostics[4], isA<DiagnosticsProperty<Element>>());
+      expect(error.diagnostics[4], isInstanceOf<DiagnosticsProperty<Element>>());
       expect(error.toStringDeep(),
         'FlutterError\n'
         '   Scaffold.of() called with a context that does not contain a\n'
@@ -1863,7 +1893,7 @@ void main() {
           'Scaffold.geometryOf().\n',
         ),
       );
-      expect(error.diagnostics[4], isA<DiagnosticsProperty<Element>>());
+      expect(error.diagnostics[4], isInstanceOf<DiagnosticsProperty<Element>>());
       expect(error.toStringDeep(),
         'FlutterError\n'
         '   Scaffold.geometryOf() called with a context that does not contain\n'

packages/flutter/test/material/scrollbar_test.dart

@@ -3,7 +3,6 @@
 // found in the LICENSE file.
 
 import 'package:flutter/cupertino.dart';
-import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/scheduler.dart';
 import 'package:flutter_test/flutter_test.dart';
@@ -153,20 +152,6 @@ void main() {
     await tester.drag(find.byType(SingleChildScrollView), const Offset(0.0, -10.0));
     await tester.pump();
     await tester.pump(const Duration(milliseconds: 200));
-    expect(find.byType(Scrollbar), paints..rrect());
-    expect(find.byType(CupertinoScrollbar), paints..rrect());
-    await gesture.up();
-    await tester.pumpAndSettle();
-
-    await tester.pumpWidget(viewWithScroll(TargetPlatform.macOS));
-    await gesture.down(
-      tester.getCenter(find.byType(SingleChildScrollView)),
-    );
-    await gesture.moveBy(const Offset(0.0, -10.0));
-    await tester.drag(find.byType(SingleChildScrollView), const Offset(0.0, -10.0));
-    await tester.pump();
-    await tester.pump(const Duration(milliseconds: 200));
-    expect(find.byType(Scrollbar), paints..rrect());
     expect(find.byType(CupertinoScrollbar), paints..rrect());
   });
 
@@ -188,7 +173,7 @@ void main() {
       );
     }
 
-    await tester.pumpWidget(viewWithScroll(debugDefaultTargetPlatformOverride));
+    await tester.pumpWidget(viewWithScroll(TargetPlatform.iOS));
     final TestGesture gesture = await tester.startGesture(
       tester.getCenter(find.byType(SingleChildScrollView))
     );
@@ -199,6 +184,6 @@ void main() {
     expect(find.byType(CupertinoScrollbar), paints..rrect());
     final CupertinoScrollbar scrollbar = find.byType(CupertinoScrollbar).evaluate().first.widget as CupertinoScrollbar;
     expect(scrollbar.controller, isNotNull);
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+  });
 
 }

packages/flutter/test/material/search_test.dart

@@ -573,8 +573,7 @@ void main() {
                           SemanticsFlag.isTextField,
                           SemanticsFlag.isFocused,
                           SemanticsFlag.isHeader,
-                          if (debugDefaultTargetPlatformOverride != TargetPlatform.iOS &&
+                          if (debugDefaultTargetPlatformOverride != TargetPlatform.iOS) SemanticsFlag.namesRoute,
-                              debugDefaultTargetPlatformOverride != TargetPlatform.macOS) SemanticsFlag.namesRoute,
                         ],
                         actions: <SemanticsAction>[
                           SemanticsAction.tap,
@@ -623,7 +622,8 @@ void main() {
       semantics.dispose();
     });
 
-    testWidgets('does not include routeName', (WidgetTester tester) async {
+    testWidgets('does not include routeName on iOS', (WidgetTester tester) async {
+      debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
       final SemanticsTester semantics = SemanticsTester(tester);
       final _TestSearchDelegate delegate = _TestSearchDelegate();
       await tester.pumpWidget(TestHomePage(
@@ -636,8 +636,9 @@ void main() {
       expect(semantics, hasSemantics(buildExpected(routeName: ''),
           ignoreId: true, ignoreRect: true, ignoreTransform: true));
 
+      debugDefaultTargetPlatformOverride = null;
       semantics.dispose();
-    }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+    });
   });
 }
 

packages/flutter/test/material/slider_test.dart

@@ -1250,14 +1250,16 @@ void main() {
         ));
 
     semantics.dispose();
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.android,  TargetPlatform.fuchsia }));
+  });
 
-  testWidgets('Slider Semantics', (WidgetTester tester) async {
+  testWidgets('Slider Semantics - iOS', (WidgetTester tester) async {
     final SemanticsTester semantics = SemanticsTester(tester);
 
     await tester.pumpWidget(
       Theme(
-        data: ThemeData.light(),
+        data: ThemeData.light().copyWith(
+          platform: TargetPlatform.iOS,
+        ),
         child: Directionality(
           textDirection: TextDirection.ltr,
           child: MediaQuery(
@@ -1292,7 +1294,7 @@ void main() {
         ignoreTransform: true,
       ));
     semantics.dispose();
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+  });
 
   testWidgets('Slider semantics with custom formatter', (WidgetTester tester) async {
     final SemanticsTester semantics = SemanticsTester(tester);
@@ -1483,34 +1485,27 @@ void main() {
       );
     }
 
-    for (final TargetPlatform platform in <TargetPlatform>[TargetPlatform.iOS, TargetPlatform.macOS]) {
+    await tester.pumpWidget(buildFrame(TargetPlatform.iOS));
-      value = 0.5;
+    expect(find.byType(Slider), findsOneWidget);
-      await tester.pumpWidget(buildFrame(platform));
+    expect(find.byType(CupertinoSlider), findsOneWidget);
-      expect(find.byType(Slider), findsOneWidget);
-      expect(find.byType(CupertinoSlider), findsOneWidget);
 
-      expect(value, 0.5, reason: 'on ${describeEnum(platform)}');
+    expect(value, 0.5);
-      final TestGesture gesture = await tester.startGesture(tester.getCenter(find.byType(CupertinoSlider)));
+    TestGesture gesture = await tester.startGesture(tester.getCenter(find.byType(CupertinoSlider)));
-      // Drag to the right end of the track.
+    // Drag to the right end of the track.
-      await gesture.moveBy(const Offset(600.0, 0.0));
+    await gesture.moveBy(const Offset(600.0, 0.0));
-      expect(value, 1.0, reason: 'on ${describeEnum(platform)}');
+    expect(value, 1.0);
-      await gesture.up();
-    }
 
-    for (final TargetPlatform platform in <TargetPlatform>[TargetPlatform.android, TargetPlatform.fuchsia]) {
+    value = 0.5;
-      value = 0.5;
+    await tester.pumpWidget(buildFrame(TargetPlatform.android));
-      await tester.pumpWidget(buildFrame(platform));
+    await tester.pumpAndSettle(); // Finish the theme change animation.
-      await tester.pumpAndSettle(); // Finish the theme change animation.
+    expect(find.byType(Slider), findsOneWidget);
-      expect(find.byType(Slider), findsOneWidget);
+    expect(find.byType(CupertinoSlider), findsNothing);
-      expect(find.byType(CupertinoSlider), findsNothing);
 
-      expect(value, 0.5, reason: 'on ${describeEnum(platform)}');
+    expect(value, 0.5);
-      final TestGesture gesture = await tester.startGesture(tester.getCenter(find.byType(Slider)));
+    gesture = await tester.startGesture(tester.getCenter(find.byType(Slider)));
-      // Drag to the right end of the track.
+    // Drag to the right end of the track.
-      await gesture.moveBy(const Offset(600.0, 0.0));
+    await gesture.moveBy(const Offset(600.0, 0.0));
-      expect(value, 1.0, reason: 'on ${describeEnum(platform)}');
+    expect(value, 1.0);
-      await gesture.up();
-    }
   });
 
   testWidgets('Slider respects height from theme', (WidgetTester tester) async {

packages/flutter/test/material/switch_list_tile_test.dart

@@ -3,7 +3,6 @@
 // found in the LICENSE file.
 
 import 'package:flutter/cupertino.dart';
-import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_test/flutter_test.dart';
 import '../rendering/mock_canvas.dart';
@@ -86,26 +85,20 @@ void main() {
       );
     }
 
-    for (final TargetPlatform platform in <TargetPlatform>[ TargetPlatform.iOS, TargetPlatform.macOS ]) {
+    await tester.pumpWidget(buildFrame(TargetPlatform.iOS));
-      value = false;
+    expect(find.byType(CupertinoSwitch), findsOneWidget);
-      await tester.pumpWidget(buildFrame(platform));
+    expect(value, isFalse);
-      expect(find.byType(CupertinoSwitch), findsOneWidget);
-      expect(value, isFalse, reason: 'on ${describeEnum(platform)}');
 
-      await tester.tap(find.byType(SwitchListTile));
+    await tester.tap(find.byType(SwitchListTile));
-      expect(value, isTrue, reason: 'on ${describeEnum(platform)}');
+    expect(value, isTrue);
-    }
 
-    for (final TargetPlatform platform in <TargetPlatform>[ TargetPlatform.android, TargetPlatform.fuchsia ]) {
+    await tester.pumpWidget(buildFrame(TargetPlatform.android));
-      value = false;
+    await tester.pumpAndSettle(); // Finish the theme change animation.
-      await tester.pumpWidget(buildFrame(platform));
-      await tester.pumpAndSettle(); // Finish the theme change animation.
 
-      expect(find.byType(CupertinoSwitch), findsNothing);
+    expect(find.byType(CupertinoSwitch), findsNothing);
-      expect(value, isFalse, reason: 'on ${describeEnum(platform)}');
+    expect(value, isTrue);
-      await tester.tap(find.byType(SwitchListTile));
+    await tester.tap(find.byType(SwitchListTile));
-      expect(value, isTrue, reason: 'on ${describeEnum(platform)}');
+    expect(value, isFalse);
-    }
   });
 
   testWidgets('SwitchListTile contentPadding', (WidgetTester tester) async {

packages/flutter/test/material/switch_test.dart

@@ -610,28 +610,23 @@ void main() {
       );
     }
 
-    for (final TargetPlatform platform in <TargetPlatform>[ TargetPlatform.iOS, TargetPlatform.macOS ]) {
+    await tester.pumpWidget(buildFrame(TargetPlatform.iOS));
-      value = false;
+    expect(find.byType(CupertinoSwitch), findsOneWidget);
-      await tester.pumpWidget(buildFrame(platform));
-      expect(find.byType(CupertinoSwitch), findsOneWidget, reason: 'on ${describeEnum(platform)}');
 
-      final CupertinoSwitch adaptiveSwitch = tester.widget(find.byType(CupertinoSwitch));
+    final CupertinoSwitch adaptiveSwitch = tester.widget(find.byType(CupertinoSwitch));
-      expect(adaptiveSwitch.trackColor, inactiveTrackColor, reason: 'on ${describeEnum(platform)}');
+    expect(adaptiveSwitch.trackColor, inactiveTrackColor);
 
-      expect(value, isFalse, reason: 'on ${describeEnum(platform)}');
+    expect(value, isFalse);
-      await tester.tap(find.byType(Switch));
+    await tester.tap(find.byType(Switch));
-      expect(value, isTrue, reason: 'on ${describeEnum(platform)}');
+    expect(value, isTrue);
-    }
+
+    await tester.pumpWidget(buildFrame(TargetPlatform.android));
+    await tester.pumpAndSettle(); // Finish the theme change animation.
+    expect(find.byType(CupertinoSwitch), findsNothing);
+    expect(value, isTrue);
+    await tester.tap(find.byType(Switch));
+    expect(value, isFalse);
 
-    for (final TargetPlatform platform in <TargetPlatform>[ TargetPlatform.android, TargetPlatform.fuchsia ]) {
-      value = false;
-      await tester.pumpWidget(buildFrame(platform));
-      await tester.pumpAndSettle(); // Finish the theme change animation.
-      expect(find.byType(CupertinoSwitch), findsNothing);
-      expect(value, isFalse, reason: 'on ${describeEnum(platform)}');
-      await tester.tap(find.byType(Switch));
-      expect(value, isTrue, reason: 'on ${describeEnum(platform)}');
-    }
   });
 
   testWidgets('Switch is focusable and has correct focus color', (WidgetTester tester) async {

packages/flutter/test/material/text_field_test.dart

@@ -304,7 +304,9 @@ void main() {
     await checkCursorToggle();
   });
 
-  testWidgets('Cursor animates', (WidgetTester tester) async {
+  testWidgets('Cursor animates on iOS', (WidgetTester tester) async {
+    debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
+
     await tester.pumpWidget(
       const MaterialApp(
         home: Material(
@@ -338,9 +340,13 @@ void main() {
     await tester.pump(const Duration(milliseconds: 50));
 
     expect(renderEditable.cursorColor.alpha, 0);
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
 
-  testWidgets('Cursor radius is 2.0', (WidgetTester tester) async {
+    debugDefaultTargetPlatformOverride = null;
+  });
+
+  testWidgets('Cursor radius is 2.0 on iOS', (WidgetTester tester) async {
+    debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
+
     await tester.pumpWidget(
       const MaterialApp(
         home: Material(
@@ -353,7 +359,9 @@ void main() {
     final RenderEditable renderEditable = editableTextState.renderEditable;
 
     expect(renderEditable.cursorRadius, const Radius.circular(2.0));
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+
+    debugDefaultTargetPlatformOverride = null;
+  });
 
   testWidgets('cursor has expected defaults', (WidgetTester tester) async {
     await tester.pumpWidget(
@@ -408,7 +416,9 @@ void main() {
     );
   });
 
-  testWidgets('Material cursor golden', (WidgetTester tester) async {
+  testWidgets('Material cursor iOS golden', (WidgetTester tester) async {
+    debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
+
     final Widget widget = overlay(
       child: const RepaintBoundary(
         key: ValueKey<int>(1),
@@ -428,13 +438,12 @@ void main() {
     await tester.tapAt(textOffsetToPosition(tester, testValue.length));
     await tester.pump();
 
+    debugDefaultTargetPlatformOverride = null;
     await expectLater(
       find.byKey(const ValueKey<int>(1)),
-      matchesGoldenFile(
+      matchesGoldenFile('text_field_cursor_test.material.1.png'),
-        'text_field_cursor_test_${describeEnum(debugDefaultTargetPlatformOverride).toLowerCase()}.material.1.png',
-      ),
     );
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+  });
 
   testWidgets('text field selection toolbar renders correctly inside opacity', (WidgetTester tester) async {
     await tester.pumpWidget(
@@ -487,13 +496,14 @@ void main() {
     );
   }, skip: isBrowser);
 
-  testWidgets('text field toolbar options correctly changes options',
+  testWidgets('text field toolbar options correctly changes options (iOS)',
       (WidgetTester tester) async {
       final TextEditingController controller = TextEditingController(
         text: 'Atwater Peel Sherbrooke Bonaventure',
       );
       await tester.pumpWidget(
         MaterialApp(
+          theme: ThemeData(platform: TargetPlatform.iOS),
           home: Material(
             child: Center(
               child: TextField(
@@ -534,9 +544,9 @@ void main() {
     expect(find.text('Copy'), findsOneWidget);
     expect(find.text('Cut'), findsNothing);
     expect(find.text('Select All'), findsNothing);
-  }, skip: isBrowser, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+  }, skip: isBrowser);
 
-  testWidgets('text field toolbar options correctly changes options',
+  testWidgets('text field toolbar options correctly changes options (Android)',
       (WidgetTester tester) async {
     final TextEditingController controller = TextEditingController(
       text: 'Atwater Peel Sherbrooke Bonaventure',
@@ -567,8 +577,10 @@ void main() {
     expect(find.text('COPY'), findsOneWidget);
     expect(find.text('CUT'), findsNothing);
     expect(find.text('SELECT ALL'), findsNothing);
-  }, skip: isBrowser, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.android,  TargetPlatform.fuchsia }));
+  }, skip: isBrowser);
 
+  // TODO(hansmuller): restore these tests after the fix for #24876 has landed.
+  /*
   testWidgets('cursor layout has correct width', (WidgetTester tester) async {
     EditableText.debugDeterministicCursor = true;
     await tester.pumpWidget(
@@ -585,10 +597,10 @@ void main() {
 
     await expectLater(
       find.byType(TextField),
-      matchesGoldenFile('text_field_cursor_width_test.0.0.png', version: 0),
+      matchesGoldenFile('text_field_test.0.0.png'),
     );
     EditableText.debugDeterministicCursor = false;
-  }, skip: !isLinux);
+  }, skip: !Platform.isLinux);
 
   testWidgets('cursor layout has correct radius', (WidgetTester tester) async {
     EditableText.debugDeterministicCursor = true;
@@ -607,10 +619,11 @@ void main() {
 
     await expectLater(
       find.byType(TextField),
-      matchesGoldenFile('text_field_cursor_width_test.1.0.png', version: 0),
+      matchesGoldenFile('text_field_test.1.0.png'),
     );
     EditableText.debugDeterministicCursor = false;
-  }, skip: !isLinux);
+  }, skip: !Platform.isLinux);
+  */
 
   testWidgets('Overflowing a line with spaces stops the cursor at the end', (WidgetTester tester) async {
     final TextEditingController controller = TextEditingController();
@@ -857,27 +870,6 @@ void main() {
     expect(handle.opacity.value, equals(1.0));
   });
 
-
-  testWidgets('Long pressing a field with selection 0,0 shows the selection menu', (WidgetTester tester) async {
-    await tester.pumpWidget(overlay(
-      child: TextField(
-        controller: TextEditingController.fromValue(
-          const TextEditingValue(
-            selection: TextSelection(baseOffset: 0, extentOffset: 0),
-          ),
-        ),
-      ),
-    ));
-
-    expect(find.text('PASTE'), findsNothing);
-
-    final Offset emptyPos = textOffsetToPosition(tester, 0);
-    await tester.longPressAt(emptyPos, pointer: 7);
-    await tester.pumpAndSettle();
-
-    expect(find.text('PASTE'), findsOneWidget);
-  });
-
   testWidgets('Entering text hides selection handle caret', (WidgetTester tester) async {
     final TextEditingController controller = TextEditingController();
 
@@ -986,10 +978,11 @@ void main() {
     expect(find.text('CUT'), findsNothing);
   });
 
-  testWidgets('does not paint toolbar when no options available', (WidgetTester tester) async {
+  testWidgets('does not paint toolbar when no options available on ios', (WidgetTester tester) async {
     await tester.pumpWidget(
-        const MaterialApp(
+        MaterialApp(
-          home: Material(
+          theme: ThemeData(platform: TargetPlatform.iOS),
+          home: const Material(
             child: TextField(
               readOnly: true,
             ),
@@ -1005,9 +998,9 @@ void main() {
     await tester.pumpAndSettle();
 
     expect(find.byType(CupertinoTextSelectionToolbar), paintsNothing);
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+  });
 
-  testWidgets('text field build empty toolbar when no options available', (WidgetTester tester) async {
+  testWidgets('text field build empty toolbar when no options available android', (WidgetTester tester) async {
     await tester.pumpWidget(
         const MaterialApp(
           home: Material(
@@ -1029,7 +1022,7 @@ void main() {
       matching: find.byType(Container),
     ));
     expect(container.size, Size.zero);
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.android,  TargetPlatform.fuchsia }));
+  });
 
   testWidgets('Sawping controllers should update selection', (WidgetTester tester) async {
     TextEditingController controller = TextEditingController(text: 'readonly');
@@ -5507,13 +5500,14 @@ void main() {
   });
 
   testWidgets(
-    'tap moves cursor to the edge of the word it tapped',
+    'tap moves cursor to the edge of the word it tapped on (iOS)',
     (WidgetTester tester) async {
       final TextEditingController controller = TextEditingController(
         text: 'Atwater Peel Sherbrooke Bonaventure',
       );
       await tester.pumpWidget(
         MaterialApp(
+          theme: ThemeData(platform: TargetPlatform.iOS),
           home: Material(
             child: Center(
               child: TextField(
@@ -5537,9 +5531,12 @@ void main() {
 
       // But don't trigger the toolbar.
       expect(find.byType(CupertinoButton), findsNothing);
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+    },
+  );
 
-  testWidgets('tap moves cursor to the position tapped', (WidgetTester tester) async {
+  testWidgets(
+    'tap moves cursor to the position tapped (Android)',
+    (WidgetTester tester) async {
       final TextEditingController controller = TextEditingController(
         text: 'Atwater Peel Sherbrooke Bonaventure',
       );
@@ -5568,16 +5565,18 @@ void main() {
 
       // But don't trigger the toolbar.
       expect(find.byType(FlatButton), findsNothing);
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.android,  TargetPlatform.fuchsia }));
+    },
+  );
 
   testWidgets(
-    'two slow taps do not trigger a word selection',
+    'two slow taps do not trigger a word selection (iOS)',
     (WidgetTester tester) async {
       final TextEditingController controller = TextEditingController(
         text: 'Atwater Peel Sherbrooke Bonaventure',
       );
       await tester.pumpWidget(
         MaterialApp(
+          theme: ThemeData(platform: TargetPlatform.iOS),
           home: Material(
             child: Center(
               child: TextField(
@@ -5603,16 +5602,18 @@ void main() {
 
       // No toolbar.
       expect(find.byType(CupertinoButton), findsNothing);
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+    },
+  );
 
   testWidgets(
-    'double tap selects word and first tap of double tap moves cursor',
+    'double tap selects word and first tap of double tap moves cursor (iOS)',
     (WidgetTester tester) async {
       final TextEditingController controller = TextEditingController(
         text: 'Atwater Peel Sherbrooke Bonaventure',
       );
       await tester.pumpWidget(
         MaterialApp(
+          theme: ThemeData(platform: TargetPlatform.iOS),
           home: Material(
             child: Center(
               child: TextField(
@@ -5648,10 +5649,11 @@ void main() {
 
       // Selected text shows 3 toolbar buttons.
       expect(find.byType(CupertinoButton), findsNWidgets(3));
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+    },
+  );
 
   testWidgets(
-    'double tap selects word and first tap of double tap moves cursor and shows toolbar',
+    'double tap selects word and first tap of double tap moves cursor and shows toolbar (Android)',
     (WidgetTester tester) async {
       final TextEditingController controller = TextEditingController(
         text: 'Atwater Peel Sherbrooke Bonaventure',
@@ -5693,10 +5695,11 @@ void main() {
 
       // Selected text shows 4 toolbar buttons: cut, copy, paste, select all
       expect(find.byType(FlatButton), findsNWidgets(4));
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.android,  TargetPlatform.fuchsia }));
+    },
+  );
 
   testWidgets(
-    'double tap on top of cursor also selects word',
+    'double tap on top of cursor also selects word (Android)',
     (WidgetTester tester) async {
       final TextEditingController controller = TextEditingController(
         text: 'Atwater Peel Sherbrooke Bonaventure',
@@ -5742,7 +5745,8 @@ void main() {
 
       // Selected text shows 4 toolbar buttons: cut, copy, paste, select all
       expect(find.byType(FlatButton), findsNWidgets(4));
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.android,  TargetPlatform.fuchsia }));
+    },
+  );
 
   testWidgets(
     'double double tap just shows the selection menu',
@@ -5869,13 +5873,14 @@ void main() {
   );
 
   testWidgets(
-    'double tap hold selects word',
+    'double tap hold selects word (iOS)',
     (WidgetTester tester) async {
       final TextEditingController controller = TextEditingController(
         text: 'Atwater Peel Sherbrooke Bonaventure',
       );
       await tester.pumpWidget(
         MaterialApp(
+          theme: ThemeData(platform: TargetPlatform.iOS),
           home: Material(
             child: Center(
               child: TextField(
@@ -5913,16 +5918,18 @@ void main() {
       );
       // The toolbar is still showing.
       expect(find.byType(CupertinoButton), findsNWidgets(3));
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+    },
+  );
 
   testWidgets(
-    'tap after a double tap select is not affected',
+    'tap after a double tap select is not affected (iOS)',
     (WidgetTester tester) async {
       final TextEditingController controller = TextEditingController(
         text: 'Atwater Peel Sherbrooke Bonaventure',
       );
       await tester.pumpWidget(
         MaterialApp(
+          theme: ThemeData(platform: TargetPlatform.iOS),
           home: Material(
             child: Center(
               child: TextField(
@@ -5959,16 +5966,18 @@ void main() {
 
       // No toolbar.
       expect(find.byType(CupertinoButton), findsNothing);
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+    },
+  );
 
   testWidgets(
-    'long press moves cursor to the exact long press position and shows toolbar',
+    'long press moves cursor to the exact long press position and shows toolbar (iOS)',
     (WidgetTester tester) async {
       final TextEditingController controller = TextEditingController(
         text: 'Atwater Peel Sherbrooke Bonaventure',
       );
       await tester.pumpWidget(
         MaterialApp(
+          theme: ThemeData(platform: TargetPlatform.iOS),
           home: Material(
             child: Center(
               child: TextField(
@@ -5992,10 +6001,11 @@ void main() {
 
       // Collapsed toolbar shows 2 buttons.
       expect(find.byType(CupertinoButton), findsNWidgets(2));
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+    },
+  );
 
   testWidgets(
-    'long press selects word and shows toolbar',
+    'long press selects word and shows toolbar (Android)',
     (WidgetTester tester) async {
       final TextEditingController controller = TextEditingController(
         text: 'Atwater Peel Sherbrooke Bonaventure',
@@ -6024,16 +6034,18 @@ void main() {
 
       // Collapsed toolbar shows 4 buttons: cut, copy, paste, select all
       expect(find.byType(FlatButton), findsNWidgets(4));
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.android,  TargetPlatform.fuchsia }));
+    },
+  );
 
   testWidgets(
-    'long press tap cannot initiate a double tap',
+    'long press tap cannot initiate a double tap (iOS)',
     (WidgetTester tester) async {
       final TextEditingController controller = TextEditingController(
         text: 'Atwater Peel Sherbrooke Bonaventure',
       );
       await tester.pumpWidget(
         MaterialApp(
+          theme: ThemeData(platform: TargetPlatform.iOS),
           home: Material(
             child: Center(
               child: TextField(
@@ -6061,16 +6073,18 @@ void main() {
 
       // Collapsed toolbar shows 2 buttons.
       expect(find.byType(CupertinoButton), findsNothing);
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+    },
+  );
 
   testWidgets(
-    'long press drag moves the cursor under the drag and shows toolbar on lift',
+    'long press drag moves the cursor under the drag and shows toolbar on lift (iOS)',
     (WidgetTester tester) async {
       final TextEditingController controller = TextEditingController(
         text: 'Atwater Peel Sherbrooke Bonaventure',
       );
       await tester.pumpWidget(
         MaterialApp(
+          theme: ThemeData(platform: TargetPlatform.iOS),
           home: Material(
             child: Center(
               child: TextField(
@@ -6127,14 +6141,16 @@ void main() {
       );
       // The toolbar now shows up.
       expect(find.byType(CupertinoButton), findsNWidgets(2));
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+    },
+  );
 
-  testWidgets('long press drag can edge scroll', (WidgetTester tester) async {
+  testWidgets('long press drag can edge scroll (iOS)', (WidgetTester tester) async {
     final TextEditingController controller = TextEditingController(
       text: 'Atwater Peel Sherbrooke Bonaventure Angrignon Peel Côte-des-Neiges',
     );
     await tester.pumpWidget(
       MaterialApp(
+        theme: ThemeData(platform: TargetPlatform.iOS),
         home: Material(
           child: Center(
             child: TextField(
@@ -6216,16 +6232,17 @@ void main() {
     expect(firstCharEndpoint.length, 1);
     // The first character is now offscreen to the left.
     expect(firstCharEndpoint[0].point.dx, moreOrLessEquals(-257, epsilon: 1));
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+  });
 
   testWidgets(
-    'long tap after a double tap select is not affected',
+    'long tap after a double tap select is not affected (iOS)',
     (WidgetTester tester) async {
       final TextEditingController controller = TextEditingController(
         text: 'Atwater Peel Sherbrooke Bonaventure',
       );
       await tester.pumpWidget(
         MaterialApp(
+          theme: ThemeData(platform: TargetPlatform.iOS),
           home: Material(
             child: Center(
               child: TextField(
@@ -6259,16 +6276,18 @@ void main() {
 
       // Long press toolbar.
       expect(find.byType(CupertinoButton), findsNWidgets(2));
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+    },
+  );
 
   testWidgets(
-    'double tap after a long tap is not affected',
+    'double tap after a long tap is not affected (iOS)',
     (WidgetTester tester) async {
       final TextEditingController controller = TextEditingController(
         text: 'Atwater Peel Sherbrooke Bonaventure',
       );
       await tester.pumpWidget(
         MaterialApp(
+          theme: ThemeData(platform: TargetPlatform.iOS),
           home: Material(
             child: Center(
               child: TextField(
@@ -6300,14 +6319,18 @@ void main() {
         const TextSelection(baseOffset: 8, extentOffset: 12),
       );
       expect(find.byType(CupertinoButton), findsNWidgets(3));
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+    },
+  );
 
-  testWidgets('double tap chains work', (WidgetTester tester) async {
+  testWidgets(
+    'double tap chains work (iOS)',
+    (WidgetTester tester) async {
       final TextEditingController controller = TextEditingController(
         text: 'Atwater Peel Sherbrooke Bonaventure',
       );
       await tester.pumpWidget(
         MaterialApp(
+          theme: ThemeData(platform: TargetPlatform.iOS),
           home: Material(
             child: Center(
               child: TextField(
@@ -6364,9 +6387,10 @@ void main() {
         const TextSelection(baseOffset: 8, extentOffset: 12),
       );
       expect(find.byType(CupertinoButton), findsNWidgets(3));
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+    },
+  );
 
-  testWidgets('force press does not select a word', (WidgetTester tester) async {
+  testWidgets('force press does not select a word on (android)', (WidgetTester tester) async {
     final TextEditingController controller = TextEditingController(
       text: 'Atwater Peel Sherbrooke Bonaventure',
     );
@@ -6394,7 +6418,7 @@ void main() {
           pressureMin: 0.0,
       ),
     );
-    await gesture.updateWithCustomEvent(PointerMoveEvent(pointer: pointerValue, position: offset + const Offset(150.0, 9.0), pressure: 0.5, pressureMin: 0, pressureMax: 1,),);
+    await gesture.updateWithCustomEvent(PointerMoveEvent(pointer: pointerValue, position: offset + const Offset(150.0, 9.0), pressure: 0.5, pressureMin: 0, pressureMax: 1));
 
     // We don't want this gesture to select any word on Android.
     expect(controller.selection, const TextSelection.collapsed(offset: -1));
@@ -6402,14 +6426,15 @@ void main() {
     await gesture.up();
     await tester.pump();
     expect(find.byType(FlatButton), findsNothing);
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.android,  TargetPlatform.fuchsia }));
+  });
 
-  testWidgets('force press selects word', (WidgetTester tester) async {
+  testWidgets('force press selects word (iOS)', (WidgetTester tester) async {
     final TextEditingController controller = TextEditingController(
       text: 'Atwater Peel Sherbrooke Bonaventure',
     );
     await tester.pumpWidget(
       MaterialApp(
+        theme: ThemeData(platform: TargetPlatform.iOS),
         home: Material(
           child: TextField(
             controller: controller,
@@ -6434,15 +6459,7 @@ void main() {
       ),
     );
 
-    await gesture.updateWithCustomEvent(
+    await gesture.updateWithCustomEvent(PointerMoveEvent(pointer: pointerValue, position: textfieldStart + const Offset(150.0, 9.0), pressure: 0.5, pressureMin: 0, pressureMax: 1));
-      PointerMoveEvent(
-        pointer: pointerValue,
-        position: textfieldStart + const Offset(150.0, 9.0),
-        pressure: 0.5,
-        pressureMin: 0,
-        pressureMax: 1,
-      ),
-    );
     // We expect the force press to select a word at the given location.
     expect(
       controller.selection,
@@ -6452,15 +6469,15 @@ void main() {
     await gesture.up();
     await tester.pump();
     expect(find.byType(CupertinoButton), findsNWidgets(3));
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+  });
 
-  testWidgets('tap on non-force-press-supported devices work', (WidgetTester tester) async {
+  testWidgets('tap on non-force-press-supported devices work (iOS)', (WidgetTester tester) async {
     final TextEditingController controller = TextEditingController(
       text: 'Atwater Peel Sherbrooke Bonaventure',
     );
-    await tester.pumpWidget(Container(key: GlobalKey()));
     await tester.pumpWidget(
       MaterialApp(
+        theme: ThemeData(platform: TargetPlatform.iOS),
         home: Material(
           child: TextField(
             controller: controller,
@@ -6486,15 +6503,7 @@ void main() {
       ),
     );
 
-    await gesture.updateWithCustomEvent(
+    await gesture.updateWithCustomEvent(PointerMoveEvent(pointer: pointerValue, position: textfieldStart + const Offset(150.0, 9.0), pressure: 0.5, pressureMin: 0, pressureMax: 1));
-      PointerMoveEvent(
-        pointer: pointerValue,
-        position: textfieldStart + const Offset(150.0, 9.0),
-        pressure: 0.5,
-        pressureMin: 0,
-        pressureMax: 1,
-      ),
-    );
     await gesture.up();
     // The event should fallback to a normal tap and move the cursor.
     // Single taps selects the edge of the word.
@@ -6506,10 +6515,7 @@ void main() {
     await tester.pump();
     // Single taps shouldn't trigger the toolbar.
     expect(find.byType(CupertinoButton), findsNothing);
-
+  });
-    // TODO(gspencergoog): Add in TargetPlatform.macOS in the line below when we figure out what global state is leaking.
-    // https://github.com/flutter/flutter/issues/43445
-  }, variant: TargetPlatformVariant.only(TargetPlatform.iOS));
 
   testWidgets('default TextField debugFillProperties', (WidgetTester tester) async {
     final DiagnosticPropertiesBuilder builder = DiagnosticPropertiesBuilder();
@@ -6916,6 +6922,7 @@ void main() {
   });
 
   testWidgets('iOS selection handles are rendered and not faded away', (WidgetTester tester) async {
+    debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
     const String testText = 'lorem ipsum';
     final TextEditingController controller = TextEditingController(text: testText);
 
@@ -6944,7 +6951,9 @@ void main() {
 
     expect(left.opacity.value, equals(1.0));
     expect(right.opacity.value, equals(1.0));
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+
+    debugDefaultTargetPlatformOverride = null;
+  });
 
   testWidgets('Tap shows handles but not toolbar', (WidgetTester tester) async {
     final TextEditingController controller = TextEditingController(

packages/flutter/test/material/theme_data_test.dart

@@ -196,7 +196,6 @@ void main() {
     const PageTransitionsTheme pageTransitionTheme = PageTransitionsTheme(
       builders: <TargetPlatform, PageTransitionsBuilder>{
         TargetPlatform.iOS: CupertinoPageTransitionsBuilder(),
-        TargetPlatform.macOS: CupertinoPageTransitionsBuilder(),
       },
     );
 

packages/flutter/test/material/typography_test.dart

@@ -21,36 +21,17 @@ void main() {
     expect(Typography(platform: TargetPlatform.fuchsia).black.title.fontFamily, 'Roboto');
   });
 
-  // Ref: https://developer.apple.com/ios/human-interface-guidelines/visual-design/typography/
-  final Matcher isDisplayFont = predicate((TextStyle s) {
-    return s.fontFamily == '.SF UI Display';
-  }, 'Uses SF Display font');
-
-  final Matcher isTextFont = predicate((TextStyle s) {
-    return s.fontFamily == '.SF UI Text';
-  }, 'Uses SF Text font');
-
   test('Typography on iOS defaults to the correct SF font family based on size', () {
-    final Typography typography = Typography(platform: TargetPlatform.iOS);
+    // Ref: https://developer.apple.com/ios/human-interface-guidelines/visual-design/typography/
-    for (final TextTheme textTheme in <TextTheme>[typography.black, typography.white]) {
+    final Matcher isDisplayFont = predicate((TextStyle s) {
-      expect(textTheme.display4, isDisplayFont);
+      return s.fontFamily == '.SF UI Display';
-      expect(textTheme.display3, isDisplayFont);
+    }, 'Uses SF Display font');
-      expect(textTheme.display2, isDisplayFont);
-      expect(textTheme.display1, isDisplayFont);
-      expect(textTheme.headline, isDisplayFont);
-      expect(textTheme.title, isDisplayFont);
-      expect(textTheme.subhead, isTextFont);
-      expect(textTheme.body2, isTextFont);
-      expect(textTheme.body1, isTextFont);
-      expect(textTheme.caption, isTextFont);
-      expect(textTheme.button, isTextFont);
-      expect(textTheme.subtitle, isTextFont);
-      expect(textTheme.overline, isTextFont);
-    }
-  });
 
-  test('Typography on macOS defaults to the correct SF font family based on size', () {
+    final Matcher isTextFont = predicate((TextStyle s) {
-    final Typography typography = Typography(platform: TargetPlatform.macOS);
+      return s.fontFamily == '.SF UI Text';
+    }, 'Uses SF Text font');
+
+    final Typography typography = Typography(platform: TargetPlatform.iOS);
     for (final TextTheme textTheme in <TextTheme>[typography.black, typography.white]) {
       expect(textTheme.display4, isDisplayFont);
       expect(textTheme.display3, isDisplayFont);

packages/flutter/test/painting/border_rtl_test.dart

@@ -502,7 +502,7 @@ void main() {
     );
     expect(
       const BorderDirectional(start: magenta3) + const BorderDirectional(start: yellow2),
-      isNot(isA<BorderDirectional>()), // see shape_border_test.dart for better tests of this case
+      isNot(isInstanceOf<BorderDirectional>()), // see shape_border_test.dart for better tests of this case
     );
     const BorderDirectional b3 = BorderDirectional(top: magenta3);
     const BorderDirectional b6 = BorderDirectional(top: magenta6);

packages/flutter/test/painting/border_test.dart

@@ -97,7 +97,7 @@ void main() {
     );
     expect(
       const Border(left: magenta3) + const Border(left: yellow2),
-      isNot(isA<Border>()), // see shape_border_test.dart for better tests of this case
+      isNot(isInstanceOf<Border>()), // see shape_border_test.dart for better tests of this case
     );
     const Border b3 = Border(top: magenta3);
     const Border b6 = Border(top: magenta6);

packages/flutter/test/painting/decoration_test.dart

@@ -223,10 +223,10 @@ void main() {
     final Invocation call = canvas.invocations.singleWhere((Invocation call) => call.memberName == #drawImageNine);
     expect(call.isMethod, isTrue);
     expect(call.positionalArguments, hasLength(4));
-    expect(call.positionalArguments[0], isA<TestImage>());
+    expect(call.positionalArguments[0], isInstanceOf<TestImage>());
     expect(call.positionalArguments[1], const Rect.fromLTRB(10.0, 20.0, 40.0, 60.0));
     expect(call.positionalArguments[2], const Rect.fromLTRB(0.0, 0.0, 100.0, 100.0));
-    expect(call.positionalArguments[3], isA<Paint>());
+    expect(call.positionalArguments[3], isInstanceOf<Paint>());
     expect(call.positionalArguments[3].isAntiAlias, false);
     expect(call.positionalArguments[3].colorFilter, colorFilter);
     expect(call.positionalArguments[3].filterQuality, FilterQuality.low);
@@ -253,8 +253,8 @@ void main() {
     }
     expect(error, isNotNull);
     expect(error.diagnostics.length, 4);
-    expect(error.diagnostics[2], isA<DiagnosticsProperty<DecorationImage>>());
+    expect(error.diagnostics[2], isInstanceOf<DiagnosticsProperty<DecorationImage>>());
-    expect(error.diagnostics[3], isA<DiagnosticsProperty<ImageConfiguration>>());
+    expect(error.diagnostics[3], isInstanceOf<DiagnosticsProperty<ImageConfiguration>>());
     expect(error.toStringDeep(),
       'FlutterError\n'
       '   DecorationImage.matchTextDirection can only be used when a\n'
@@ -375,10 +375,10 @@ void main() {
   });
 
   test('Decoration.lerp with unrelated decorations', () {
-    expect(Decoration.lerp(const FlutterLogoDecoration(), const BoxDecoration(), 0.0), isA<FlutterLogoDecoration>()); // ignore: CONST_EVAL_THROWS_EXCEPTION
+    expect(Decoration.lerp(const FlutterLogoDecoration(), const BoxDecoration(), 0.0), isInstanceOf<FlutterLogoDecoration>()); // ignore: CONST_EVAL_THROWS_EXCEPTION
-    expect(Decoration.lerp(const FlutterLogoDecoration(), const BoxDecoration(), 0.25), isA<FlutterLogoDecoration>()); // ignore: CONST_EVAL_THROWS_EXCEPTION
+    expect(Decoration.lerp(const FlutterLogoDecoration(), const BoxDecoration(), 0.25), isInstanceOf<FlutterLogoDecoration>()); // ignore: CONST_EVAL_THROWS_EXCEPTION
-    expect(Decoration.lerp(const FlutterLogoDecoration(), const BoxDecoration(), 0.75), isA<BoxDecoration>()); // ignore: CONST_EVAL_THROWS_EXCEPTION
+    expect(Decoration.lerp(const FlutterLogoDecoration(), const BoxDecoration(), 0.75), isInstanceOf<BoxDecoration>()); // ignore: CONST_EVAL_THROWS_EXCEPTION
-    expect(Decoration.lerp(const FlutterLogoDecoration(), const BoxDecoration(), 1.0), isA<BoxDecoration>()); // ignore: CONST_EVAL_THROWS_EXCEPTION
+    expect(Decoration.lerp(const FlutterLogoDecoration(), const BoxDecoration(), 1.0), isInstanceOf<BoxDecoration>()); // ignore: CONST_EVAL_THROWS_EXCEPTION
   });
 
   test('paintImage BoxFit.none scale test', () {
@@ -406,7 +406,7 @@ void main() {
       expect(call.isMethod, isTrue);
       expect(call.positionalArguments, hasLength(4));
 
-      expect(call.positionalArguments[0], isA<TestImage>());
+      expect(call.positionalArguments[0], isInstanceOf<TestImage>());
 
       // sourceRect should contain all pixels of the source image
       expect(call.positionalArguments[1], Offset.zero & imageSize);
@@ -420,7 +420,7 @@ void main() {
       );
       expect(call.positionalArguments[2], expectedTileRect);
 
-      expect(call.positionalArguments[3], isA<Paint>());
+      expect(call.positionalArguments[3], isInstanceOf<Paint>());
     }
   });
 
@@ -450,7 +450,7 @@ void main() {
       expect(call.isMethod, isTrue);
       expect(call.positionalArguments, hasLength(4));
 
-      expect(call.positionalArguments[0], isA<TestImage>());
+      expect(call.positionalArguments[0], isInstanceOf<TestImage>());
 
       // sourceRect should contain all pixels of the source image
       expect(call.positionalArguments[1], Offset.zero & imageSize);
@@ -464,7 +464,7 @@ void main() {
       );
       expect(call.positionalArguments[2], expectedTileRect);
 
-      expect(call.positionalArguments[3], isA<Paint>());
+      expect(call.positionalArguments[3], isInstanceOf<Paint>());
     }
   });
 
@@ -493,7 +493,7 @@ void main() {
     expect(call.isMethod, isTrue);
     expect(call.positionalArguments, hasLength(4));
 
-    expect(call.positionalArguments[0], isA<TestImage>());
+    expect(call.positionalArguments[0], isInstanceOf<TestImage>());
 
     // sourceRect should contain all pixels of the source image
     expect(call.positionalArguments[1], Offset.zero & imageSize);
@@ -507,7 +507,7 @@ void main() {
     );
     expect(call.positionalArguments[2], expectedTileRect);
 
-    expect(call.positionalArguments[3], isA<Paint>());
+    expect(call.positionalArguments[3], isInstanceOf<Paint>());
   });
 
   test('paintImage boxFit, scale and alignment test', () {

packages/flutter/test/painting/edge_insets_test.dart

@@ -175,7 +175,7 @@ void main() {
 
   test('EdgeInsetsGeometry operators', () {
     final EdgeInsetsGeometry a = const EdgeInsetsDirectional.fromSTEB(1.0, 2.0, 3.0, 5.0).add(EdgeInsets.zero);
-    expect(a, isNot(isA<EdgeInsetsDirectional>()));
+    expect(a, isNot(isInstanceOf<EdgeInsetsDirectional>()));
     expect(a * 2.0, const EdgeInsetsDirectional.fromSTEB(2.0, 4.0, 6.0, 10.0));
     expect(a / 2.0, const EdgeInsetsDirectional.fromSTEB(0.5, 1.0, 1.5, 2.5));
     expect(a % 2.0, const EdgeInsetsDirectional.fromSTEB(1.0, 0.0, 1.0, 1.0));

packages/flutter/test/painting/image_cache_test.dart

@@ -133,7 +133,7 @@ void main() {
 
     test('Returns null if an error is caught resolving an image', () {
       final ErrorImageProvider errorImage = ErrorImageProvider();
-      expect(() => imageCache.putIfAbsent(errorImage, () => errorImage.load(errorImage, null)), throwsA(isA<Error>()));
+      expect(() => imageCache.putIfAbsent(errorImage, () => errorImage.load(errorImage, null)), throwsA(isInstanceOf<Error>()));
       bool caughtError = false;
       final ImageStreamCompleter result = imageCache.putIfAbsent(errorImage, () => errorImage.load(errorImage, null), onError: (dynamic error, StackTrace stackTrace) {
         caughtError = true;

packages/flutter/test/painting/image_provider_test.dart

@@ -11,6 +11,7 @@ import 'package:flutter/foundation.dart';
 import 'package:flutter/painting.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:mockito/mockito.dart';
+import 'package:test_api/test_api.dart' show TypeMatcher; // ignore: deprecated_member_use
 
 import '../rendering/rendering_tester.dart';
 import 'image_data.dart';
@@ -181,7 +182,7 @@ void main() {
         final dynamic err = await caughtError.future;
         expect(
           err,
-          isA<NetworkImageLoadException>()
+          const TypeMatcher<NetworkImageLoadException>()
             .having((NetworkImageLoadException e) => e.statusCode, 'statusCode', errorStatusCode)
             .having((NetworkImageLoadException e) => e.uri, 'uri', Uri.base.resolve(requestUrl)),
         );

packages/flutter/test/rendering/aspect_ratio_test.dart

@@ -4,8 +4,7 @@
 
 import 'package:flutter/foundation.dart';
 import 'package:flutter/rendering.dart';
-import 'package:flutter_test/flutter_test.dart';
+import '../flutter_test_alternative.dart';
-
 import 'rendering_tester.dart';
 
 void main() {
@@ -114,7 +113,7 @@ void main() {
       errors.addAll(renderer.takeAllFlutterErrorDetails());
     });
     expect(errors, hasLength(2));
-    expect(errors.first.exception, isFlutterError);
+    expect(errors.first.exception, isA<FlutterError>());
     expect(errors.first.exception.toStringDeep(),
       'FlutterError\n'
       '   RenderAspectRatio has unbounded constraints.\n'

packages/flutter/test/rendering/box_constraints_test.dart

@@ -3,7 +3,7 @@
 // found in the LICENSE file.
 
 import 'package:flutter/rendering.dart';
-import 'package:flutter_test/flutter_test.dart';
+import '../flutter_test_alternative.dart';
 
 void main() {
   test('BoxConstraints toString', () {
@@ -153,9 +153,9 @@ void main() {
       minHeight: 20.0,
       maxHeight: 30.0,
     );
-    expect(() => BoxConstraints.lerp(constraints1, constraints2, 0.5), throwsAssertionError);
+    expect(() => BoxConstraints.lerp(constraints1, constraints2, 0.5), throwsA(isInstanceOf<AssertionError>()));
-    expect(() => BoxConstraints.lerp(constraints1, constraints3, 0.5), throwsAssertionError);
+    expect(() => BoxConstraints.lerp(constraints1, constraints3, 0.5), throwsA(isInstanceOf<AssertionError>()));
-    expect(() => BoxConstraints.lerp(constraints2, constraints3, 0.5), throwsAssertionError);
+    expect(() => BoxConstraints.lerp(constraints2, constraints3, 0.5), throwsA(isInstanceOf<AssertionError>()));
   });
 
   test('BoxConstraints normalize', () {

packages/flutter/test/rendering/debug_overflow_indicator_test.dart

@@ -34,7 +34,7 @@ void main() {
     );
 
     final dynamic exception = tester.takeException();
-    expect(exception, isFlutterError);
+    expect(exception, isInstanceOf<FlutterError>());
     expect(exception.diagnostics.first.level, DiagnosticLevel.summary);
     expect(exception.diagnostics.first.toString(), startsWith('A RenderUnconstrainedBox overflowed by '));
     expect(find.byType(UnconstrainedBox), paints..rect());

packages/flutter/test/rendering/flex_test.dart

@@ -388,7 +388,7 @@ void main() {
       exceptions.addAll(renderer.takeAllFlutterExceptions());
     });
     expect(exceptions, isNotEmpty);
-    expect(exceptions.first, isFlutterError);
+    expect(exceptions.first, isInstanceOf<FlutterError>());
   });
 
   test('MainAxisSize.min inside unconstrained', () {
@@ -416,7 +416,7 @@ void main() {
       exceptions.addAll(renderer.takeAllFlutterExceptions());
     });
     expect(exceptions, isNotEmpty);
-    expect(exceptions.first, isFlutterError);
+    expect(exceptions.first, isInstanceOf<FlutterError>());
   });
 
   test('MainAxisSize.min inside tightly constrained', () {

packages/flutter/test/rendering/object_test.dart

@@ -148,7 +148,7 @@ void _testPaintingContextLayerReuse<L extends Layer>(_LayerTestPaintCallback pai
   box.markNeedsPaint();
   pumpFrame(phase: EnginePhase.paint);
   expect(box.paintedLayers, hasLength(2));
-  expect(box.paintedLayers[0], isA<L>());
+  expect(box.paintedLayers[0], isInstanceOf<L>());
   expect(box.paintedLayers[0], same(box.paintedLayers[1]));
 }
 

packages/flutter/test/rendering/proxy_box_test.dart

@@ -81,25 +81,21 @@ void main() {
   });
 
   test('RenderPhysicalModel compositing on non-Fuchsia', () {
-    for (final TargetPlatform platform in TargetPlatform.values) {
+    debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
-      if (platform == TargetPlatform.fuchsia) {
-        continue;
-      }
-      debugDefaultTargetPlatformOverride = platform;
 
-      final RenderPhysicalModel root = RenderPhysicalModel(color: const Color(0xffff00ff));
+    final RenderPhysicalModel root = RenderPhysicalModel(color: const Color(0xffff00ff));
-      layout(root, phase: EnginePhase.composite);
+    layout(root, phase: EnginePhase.composite);
-      expect(root.needsCompositing, isTrue);
+    expect(root.needsCompositing, isTrue);
 
-      // Flutter now composites physical shapes on all platforms.
+    // Flutter now composites physical shapes on all platforms.
-      root.elevation = 1.0;
+    root.elevation = 1.0;
-      pumpFrame(phase: EnginePhase.composite);
+    pumpFrame(phase: EnginePhase.composite);
-      expect(root.needsCompositing, isTrue);
+    expect(root.needsCompositing, isTrue);
+
+    root.elevation = 0.0;
+    pumpFrame(phase: EnginePhase.composite);
+    expect(root.needsCompositing, isTrue);
 
-      root.elevation = 0.0;
-      pumpFrame(phase: EnginePhase.composite);
-      expect(root.needsCompositing, isTrue);
-    }
     debugDefaultTargetPlatformOverride = null;
   });
 
@@ -125,53 +121,44 @@ void main() {
   });
 
   group('RenderPhysicalShape', () {
+    setUp(() {
+      debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
+    });
+
     test('shape change triggers repaint', () {
-      for (final TargetPlatform platform in TargetPlatform.values) {
+      final RenderPhysicalShape root = RenderPhysicalShape(
-        if (platform == TargetPlatform.fuchsia) {
+        color: const Color(0xffff00ff),
-          continue;
+        clipper: const ShapeBorderClipper(shape: CircleBorder()),
-        }
+      );
-        debugDefaultTargetPlatformOverride = platform;
+      layout(root, phase: EnginePhase.composite);
+      expect(root.debugNeedsPaint, isFalse);
 
-        final RenderPhysicalShape root = RenderPhysicalShape(
+      // Same shape, no repaint.
-          color: const Color(0xffff00ff),
+      root.clipper = const ShapeBorderClipper(shape: CircleBorder());
-          clipper: const ShapeBorderClipper(shape: CircleBorder()),
+      expect(root.debugNeedsPaint, isFalse);
-        );
-        layout(root, phase: EnginePhase.composite);
-        expect(root.debugNeedsPaint, isFalse);
 
-        // Same shape, no repaint.
+      // Different shape triggers repaint.
-        root.clipper = const ShapeBorderClipper(shape: CircleBorder());
+      root.clipper = const ShapeBorderClipper(shape: StadiumBorder());
-        expect(root.debugNeedsPaint, isFalse);
+      expect(root.debugNeedsPaint, isTrue);
-
-        // Different shape triggers repaint.
-        root.clipper = const ShapeBorderClipper(shape: StadiumBorder());
-        expect(root.debugNeedsPaint, isTrue);
-      }
-      debugDefaultTargetPlatformOverride = null;
     });
 
     test('compositing on non-Fuchsia', () {
-      for (final TargetPlatform platform in TargetPlatform.values) {
+      final RenderPhysicalShape root = RenderPhysicalShape(
-        if (platform == TargetPlatform.fuchsia) {
+        color: const Color(0xffff00ff),
-          continue;
+        clipper: const ShapeBorderClipper(shape: CircleBorder()),
-        }
+      );
-        debugDefaultTargetPlatformOverride = platform;
+      layout(root, phase: EnginePhase.composite);
-        final RenderPhysicalShape root = RenderPhysicalShape(
+      expect(root.needsCompositing, isTrue);
-          color: const Color(0xffff00ff),
-          clipper: const ShapeBorderClipper(shape: CircleBorder()),
-        );
-        layout(root, phase: EnginePhase.composite);
-        expect(root.needsCompositing, isTrue);
 
-        // On non-Fuchsia platforms, we composite physical shape layers
+      // On non-Fuchsia platforms, we composite physical shape layers
-        root.elevation = 1.0;
+      root.elevation = 1.0;
-        pumpFrame(phase: EnginePhase.composite);
+      pumpFrame(phase: EnginePhase.composite);
-        expect(root.needsCompositing, isTrue);
+      expect(root.needsCompositing, isTrue);
+
+      root.elevation = 0.0;
+      pumpFrame(phase: EnginePhase.composite);
+      expect(root.needsCompositing, isTrue);
 
-        root.elevation = 0.0;
-        pumpFrame(phase: EnginePhase.composite);
-        expect(root.needsCompositing, isTrue);
-      }
       debugDefaultTargetPlatformOverride = null;
     });
   });
@@ -467,6 +454,18 @@ void main() {
     // transform -> clip
     _testFittedBoxWithClipRectLayer();
   });
+
+  test('RenderFractionalTranslation updates its semantics after its translation value is set', () {
+    final _TestSemanticsUpdateRenderFractionalTranslation box = _TestSemanticsUpdateRenderFractionalTranslation(
+      translation: const Offset(0.5, 0.5),
+    );
+    layout(box, constraints: BoxConstraints.tight(const Size(200.0, 200.0)));
+    expect(box.markNeedsSemanticsUpdateCallCount, 1);
+    box.translation = const Offset(0.4, 0.4);
+    expect(box.markNeedsSemanticsUpdateCallCount, 2);
+    box.translation = const Offset(0.3, 0.3);
+    expect(box.markNeedsSemanticsUpdateCallCount, 3);
+  });
 }
 
 class _TestRectClipper extends CustomClipper<Rect> {
@@ -503,7 +502,7 @@ void _testLayerReuse<L extends Layer>(RenderBox renderObject) {
   expect(renderObject.debugLayer, null);
   layout(renderObject, phase: EnginePhase.paint, constraints: BoxConstraints.tight(const Size(10, 10)));
   final Layer layer = renderObject.debugLayer;
-  expect(layer, isA<L>());
+  expect(layer, isInstanceOf<L>());
   expect(layer, isNotNull);
 
   // Mark for repaint otherwise pumpFrame is a noop.
@@ -523,3 +522,18 @@ class _TestPathClipper extends CustomClipper<Path> {
   @override
   bool shouldReclip(_TestPathClipper oldClipper) => false;
 }
+
+class _TestSemanticsUpdateRenderFractionalTranslation extends RenderFractionalTranslation {
+  _TestSemanticsUpdateRenderFractionalTranslation({
+    @required Offset translation,
+    RenderBox child,
+  }) : super(translation: translation, child: child);
+
+  int markNeedsSemanticsUpdateCallCount = 0;
+
+  @override
+  void markNeedsSemanticsUpdate() {
+    markNeedsSemanticsUpdateCallCount++;
+    super.markNeedsSemanticsUpdate();
+  }
+}

packages/flutter/test/rendering/repaint_boundary_test.dart

@@ -60,7 +60,7 @@ void main() {
       child: repaintBoundary,
     );
     layout(opacity, phase: EnginePhase.flushSemantics);
-    expect(repaintBoundary.debugLayer, isA<OffsetLayer>());
+    expect(repaintBoundary.debugLayer, isInstanceOf<OffsetLayer>());
   });
 
   test('Framework does not create an OffsetLayer for a non-repaint boundary', () {
@@ -80,7 +80,7 @@ void main() {
       child: compositedBox,
     );
     layout(opacity, phase: EnginePhase.flushSemantics);
-    expect(compositedBox.debugLayer, isA<OpacityLayer>());
+    expect(compositedBox.debugLayer, isInstanceOf<OpacityLayer>());
   });
 
   test('Framework ensures repaint boundary layer is not overwritten', () {

packages/flutter/test/rendering/viewport_test.dart

@@ -1145,8 +1145,10 @@ void main() {
     );
   });
 
-  testWidgets('Handles infinite constraints when TargetPlatform is iOS or macOS', (WidgetTester tester) async {
+  testWidgets('Handles infinite constraints when TargetPlatform is iOS', (WidgetTester tester) async {
     // regression test for https://github.com/flutter/flutter/issues/45866
+    final TargetPlatform oldTargetPlatform = debugDefaultTargetPlatformOverride;
+    debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
     await tester.pumpWidget(
       Directionality(
         textDirection: TextDirection.ltr,
@@ -1175,5 +1177,6 @@ void main() {
     expect(find.text('b'), findsOneWidget);
     await tester.drag(find.text('b'), const Offset(0, 200));
     await tester.pumpAndSettle();
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS, TargetPlatform.macOS }));
+    debugDefaultTargetPlatformOverride = oldTargetPlatform;
+  });
 }

packages/flutter/test/scheduler/ticker_test.dart

@@ -33,7 +33,7 @@ void main() {
     }
     expect(error, isNotNull);
     expect(error.diagnostics.length, 3);
-    expect(error.diagnostics.last, isA<DiagnosticsProperty<Ticker>>());
+    expect(error.diagnostics.last, isInstanceOf<DiagnosticsProperty<Ticker>>());
     expect(
       error.toStringDeep(),
       startsWith(

packages/flutter/test/services/asset_bundle_test.dart

@@ -68,7 +68,7 @@ void main() {
     }
     expect(error, isNotNull);
     expect(error.diagnostics.length, 2);
-    expect(error.diagnostics.last, isA<IntProperty>());
+    expect(error.diagnostics.last, isInstanceOf<IntProperty>());
     expect(
       error.toStringDeep(),
       'FlutterError\n'

packages/flutter/test/services/platform_channel_test.dart

@@ -70,7 +70,7 @@ void main() {
           }
         },
       );
-      expect(channel.invokeMethod<List<String>>('sayHello', 'hello'), throwsA(isCastError));
+      expect(channel.invokeMethod<List<String>>('sayHello', 'hello'), throwsA(isInstanceOf<CastError>()));
       expect(await channel.invokeListMethod<String>('sayHello', 'hello'), <String>['hello', 'world']);
     });
 
@@ -102,7 +102,7 @@ void main() {
           }
         },
       );
-      expect(channel.invokeMethod<Map<String, String>>('sayHello', 'hello'), throwsA(isCastError));
+      expect(channel.invokeMethod<Map<String, String>>('sayHello', 'hello'), throwsA(isInstanceOf<CastError>()));
       expect(await channel.invokeMapMethod<String, String>('sayHello', 'hello'), <String, String>{'hello': 'world'});
     });
 
@@ -292,7 +292,7 @@ void main() {
       await Future<void>.delayed(Duration.zero);
       expect(events, isEmpty);
       expect(errors, hasLength(1));
-      expect(errors[0], isA<PlatformException>());
+      expect(errors[0], isInstanceOf<PlatformException>());
       final PlatformException error = errors[0] as PlatformException;
       expect(error.code, '404');
       expect(error.message, 'Not Found.');

packages/flutter/test/services/platform_views_test.dart

@@ -27,7 +27,7 @@ void main() {
             layoutDirection: TextDirection.ltr,
           ).setSize(const Size(100.0, 100.0));
         },
-        throwsA(isA<PlatformException>()),
+        throwsA(isInstanceOf<PlatformException>()),
       );
     });
 
@@ -55,7 +55,7 @@ void main() {
       expect(
           () => PlatformViewsService.initAndroidView(
               id: 0, viewType: 'web', layoutDirection: TextDirection.ltr).setSize(const Size(100.0, 100.0)),
-          throwsA(isA<PlatformException>()));
+          throwsA(isInstanceOf<PlatformException>()));
     });
 
     test('dispose Android view', () async {
@@ -170,7 +170,7 @@ void main() {
             layoutDirection: TextDirection.ltr,
           );
         },
-        throwsA(isA<PlatformException>()),
+        throwsA(isInstanceOf<PlatformException>()),
       );
     });
 
@@ -199,7 +199,7 @@ void main() {
       expect(
             () => PlatformViewsService.initUiKitView(
             id: 0, viewType: 'web', layoutDirection: TextDirection.ltr),
-        throwsA(isA<PlatformException>()),
+        throwsA(isInstanceOf<PlatformException>()),
       );
     });
 
@@ -228,7 +228,7 @@ void main() {
           () async {
             await viewController.dispose();
           },
-          throwsA(isA<PlatformException>()),
+          throwsA(isInstanceOf<PlatformException>()),
       );
     });
   });

packages/flutter/test/widgets/animated_list_test.dart

@@ -344,7 +344,7 @@ void main() {
         'https://api.flutter.dev/flutter/widgets/AnimatedListState-class.html\n'
       ),
     );
-    expect(error.diagnostics[3], isA<DiagnosticsProperty<Element>>());
+    expect(error.diagnostics[3], isInstanceOf<DiagnosticsProperty<Element>>());
     expect(
       error.toStringDeep(),
       equalsIgnoringHashCodes(

packages/flutter/test/widgets/animated_switcher_test.dart

@@ -262,7 +262,7 @@ void main() {
 
     expect(find.byType(Column), findsOneWidget);
     for (final Widget child in foundChildren) {
-      expect(child, isA<KeyedSubtree>());
+      expect(child, isInstanceOf<KeyedSubtree>());
     }
 
     await tester.pumpWidget(
@@ -280,7 +280,7 @@ void main() {
     await tester.pump(const Duration(milliseconds: 50));
 
     for (final Widget child in foundChildren) {
-      expect(child, isA<KeyedSubtree>());
+      expect(child, isInstanceOf<KeyedSubtree>());
       expect(
         find.descendant(of: find.byWidget(child), matching: find.byType(SizeTransition)),
         findsOneWidget,
@@ -430,7 +430,7 @@ void main() {
 
     expect(foundChildren.length, equals(3));
     for (final Widget child in foundChildren) {
-      expect(child, isA<KeyedSubtree>());
+      expect(child, isInstanceOf<KeyedSubtree>());
       expect(
         find.descendant(of: find.byWidget(child), matching: find.byType(FadeTransition)),
         findsOneWidget,
@@ -460,7 +460,7 @@ void main() {
 
     expect(foundChildren.length, equals(3));
     for (final Widget child in foundChildren) {
-      expect(child, isA<KeyedSubtree>());
+      expect(child, isInstanceOf<KeyedSubtree>());
       expect(
         find.descendant(of: find.byWidget(child), matching: find.byType(ScaleTransition)),
         findsOneWidget,

packages/flutter/test/widgets/app_navigator_key_test.dart

@@ -20,7 +20,7 @@ void main() {
       color: const Color(0xFF112233),
       onGenerateRoute: generateRoute,
     ));
-    expect(key.currentState, isA<NavigatorState>());
+    expect(key.currentState, isInstanceOf<NavigatorState>());
     await tester.pumpWidget(WidgetsApp(
       color: const Color(0xFF112233),
       onGenerateRoute: generateRoute,
@@ -31,6 +31,6 @@ void main() {
       color: const Color(0xFF112233),
       onGenerateRoute: generateRoute,
     ));
-    expect(key.currentState, isA<NavigatorState>());
+    expect(key.currentState, isInstanceOf<NavigatorState>());
   });
 }

packages/flutter/test/widgets/basic_test.dart

@@ -145,6 +145,69 @@ void main() {
       await tester.tap(find.byKey(key1));
       expect(_pointerDown, isTrue);
     });
+
+    testWidgets('semantics bounds are updated', (WidgetTester tester) async {
+      final GlobalKey fractionalTranslationKey = GlobalKey();
+      final GlobalKey textKey = GlobalKey();
+      Offset offset = const Offset(0.4, 0.4);
+
+      await tester.pumpWidget(
+        StatefulBuilder(
+          builder: (BuildContext context, StateSetter setState) {
+            return Directionality(
+              textDirection: TextDirection.ltr,
+              child: Center(
+                child: Semantics(
+                  explicitChildNodes: true,
+                  child: FractionalTranslation(
+                    key: fractionalTranslationKey,
+                    translation: offset,
+                    transformHitTests: true,
+                    child: GestureDetector(
+                      onTap: () {
+                        setState(() {
+                          offset = const Offset(0.8, 0.8);
+                        });
+                      },
+                      child: SizedBox(
+                        width: 100.0,
+                        height: 100.0,
+                        child: Text(
+                          'foo',
+                          key: textKey,
+                        ),
+                      ),
+                    ),
+                  ),
+                ),
+              ),
+            );
+          },
+        )
+      );
+
+      expect(
+        tester.getSemantics(find.byKey(textKey)).transform,
+        Matrix4(
+          3.0, 0.0, 0.0, 0.0,
+          0.0, 3.0, 0.0, 0.0,
+          0.0, 0.0, 1.0, 0.0,
+          1170.0, 870.0, 0.0, 1.0,
+        ),
+      );
+
+      await tester.tap(find.byKey(fractionalTranslationKey));
+      await tester.pump();
+      expect(
+        tester.getSemantics(find.byKey(textKey)).transform,
+        Matrix4(
+          3.0, 0.0, 0.0, 0.0,
+          0.0, 3.0, 0.0, 0.0,
+          0.0, 0.0, 1.0, 0.0,
+          1290.0, 990.0, 0.0, 1.0,
+        ),
+      );
+    });
   });
 
   group('Row', () {

packages/flutter/test/widgets/debug_test.dart

@@ -74,7 +74,7 @@ void main() {
           } finally {
             expect(error, isNotNull);
             expect(error.diagnostics.length, 4);
-            expect(error.diagnostics[2], isA<DiagnosticsProperty<Element>>());
+            expect(error.diagnostics[2], isInstanceOf<DiagnosticsProperty<Element>>());
             expect(
               error.toStringDeep(),
               equalsIgnoringHashCodes(
@@ -106,7 +106,7 @@ void main() {
           } finally {
             expect(error, isNotNull);
             expect(error.diagnostics.length, 5);
-            expect(error.diagnostics[2], isA<DiagnosticsProperty<Element>>());
+            expect(error.diagnostics[2], isInstanceOf<DiagnosticsProperty<Element>>());
             expect(error.diagnostics.last.level, DiagnosticLevel.hint);
             expect(
               error.diagnostics.last.toStringDeep(),
@@ -147,7 +147,7 @@ void main() {
     } finally {
       expect(error, isNotNull);
       expect(error.diagnostics.length, 4);
-      expect(error.diagnostics[1], isA<DiagnosticsProperty<Widget>>());
+      expect(error.diagnostics[1], isInstanceOf<DiagnosticsProperty<Widget>>());
       expect(error.diagnostics[1].style, DiagnosticsTreeStyle.errorProperty);
       expect(
         error.diagnostics[1].toStringDeep(),
@@ -190,7 +190,7 @@ void main() {
     } finally {
       expect(error, isNotNull);
       expect(error.diagnostics.length, 3);
-      expect(error.diagnostics[1], isA<DiagnosticsProperty<Widget>>());
+      expect(error.diagnostics[1], isInstanceOf<DiagnosticsProperty<Widget>>());
       expect(error.diagnostics[1].style, DiagnosticsTreeStyle.errorProperty);
       expect(
         error.diagnostics[1].toStringDeep(),

packages/flutter/test/widgets/draggable_scrollable_sheet_test.dart

@@ -105,7 +105,7 @@ void main() {
         expect(find.text('Item 1'), findsOneWidget);
         expect(find.text('Item 21'), findsOneWidget);
         expect(find.text('Item 31'), findsOneWidget);
-      }, skip: isBrowser, variant: TargetPlatformVariant.all());
+      }, skip: isBrowser);
 
       testWidgets('Can be dragged down when not full height', (WidgetTester tester) async {
         await tester.pumpWidget(_boilerplate(null));
@@ -118,7 +118,7 @@ void main() {
         expect(find.text('Item 1'), findsOneWidget);
         expect(find.text('Item 21'), findsNothing);
         expect(find.text('Item 36'), findsNothing);
-      }, skip: isBrowser, variant: TargetPlatformVariant.all());
+      }, skip: isBrowser);
 
       testWidgets('Can be dragged down when list is shorter than full height', (WidgetTester tester) async {
         await tester.pumpWidget(_boilerplate(null, itemCount: 30, initialChildSize: .25));
@@ -135,7 +135,7 @@ void main() {
         await tester.pumpAndSettle();
         expect(find.text('Item 1').hitTestable(), findsOneWidget);
         expect(find.text('Item 29').hitTestable(), findsNothing);
-      }, skip: isBrowser, variant: TargetPlatformVariant.all());
+      }, skip: isBrowser);
 
       testWidgets('Can be dragged up and cover its container and scroll in single motion, and then dragged back down', (WidgetTester tester) async {
         int taps = 0;
@@ -164,7 +164,7 @@ void main() {
         expect(find.text('Item 1'), findsOneWidget);
         expect(find.text('Item 18'), findsOneWidget);
         expect(find.text('Item 36'), findsNothing);
-      }, skip: isBrowser, variant: TargetPlatformVariant.all());
+      }, skip: isBrowser);
 
       testWidgets('Can be flung up gently', (WidgetTester tester) async {
         int taps = 0;
@@ -187,7 +187,7 @@ void main() {
         expect(find.text('Item 21'), findsOneWidget);
         expect(find.text('Item 36'), findsOneWidget);
         expect(find.text('Item 70'), findsNothing);
-      }, skip: isBrowser, variant: TargetPlatformVariant.all());
+      }, skip: isBrowser);
 
       testWidgets('Can be flung up', (WidgetTester tester) async {
         int taps = 0;
@@ -208,7 +208,7 @@ void main() {
         expect(find.text('Item 1'), findsNothing);
         expect(find.text('Item 21'), findsNothing);
         expect(find.text('Item 70'), findsOneWidget);
-      }, skip: isBrowser, variant: TargetPlatformVariant.all());
+      }, skip: isBrowser);
 
       testWidgets('Can be flung down when not full height', (WidgetTester tester) async {
         await tester.pumpWidget(_boilerplate(null));
@@ -221,7 +221,7 @@ void main() {
         expect(find.text('Item 1'), findsOneWidget);
         expect(find.text('Item 21'), findsNothing);
         expect(find.text('Item 36'), findsNothing);
-      }, skip: isBrowser, variant: TargetPlatformVariant.all());
+      }, skip: isBrowser);
 
       testWidgets('Can be flung up and then back down', (WidgetTester tester) async {
         int taps = 0;
@@ -260,7 +260,7 @@ void main() {
         expect(find.text('Item 1'), findsOneWidget);
         expect(find.text('Item 21'), findsNothing);
         expect(find.text('Item 70'), findsNothing);
-      }, skip: isBrowser, variant: TargetPlatformVariant.all());
+      }, skip: isBrowser);
 
       debugDefaultTargetPlatformOverride = null;
     });

packages/flutter/test/widgets/drawer_test.dart

@@ -304,7 +304,9 @@ void main() {
     expect(buttonPressed, equals(true));
   });
 
-  testWidgets('Dismissible ModalBarrier includes button in semantic tree', (WidgetTester tester) async {
+  testWidgets('Dismissible ModalBarrier includes button in semantic tree on iOS', (WidgetTester tester) async {
+    debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
+
     final SemanticsTester semantics = SemanticsTester(tester);
     final GlobalKey<ScaffoldState> scaffoldKey = GlobalKey<ScaffoldState>();
 
@@ -329,7 +331,9 @@ void main() {
     expect(semantics, includesNodeWith(label: 'Dismiss'));
 
     semantics.dispose();
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+
+    debugDefaultTargetPlatformOverride = null;
+  });
 
   testWidgets('Dismissible ModalBarrier is hidden on Android (back button is used to dismiss)', (WidgetTester tester) async {
     final SemanticsTester semantics = SemanticsTester(tester);
@@ -357,7 +361,7 @@ void main() {
     expect(semantics, isNot(includesNodeWith(label: 'Dismiss')));
 
     semantics.dispose();
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.android }));
+  });
 
   testWidgets('Drawer contains route semantics flags', (WidgetTester tester) async {
     final SemanticsTester semantics = SemanticsTester(tester);

packages/flutter/test/widgets/editable_text_cursor_test.dart

@@ -145,9 +145,10 @@ void main() {
     );
   });
 
-  testWidgets('Cursor animates', (WidgetTester tester) async {
+  testWidgets('Cursor animates on iOS', (WidgetTester tester) async {
-    const Widget widget = MaterialApp(
+    final Widget widget = MaterialApp(
-      home: Material(
+      theme: ThemeData(platform: TargetPlatform.iOS),
+      home: const Material(
         child: TextField(
           maxLines: 3,
         ),
@@ -199,7 +200,7 @@ void main() {
     // Cursor starts coming back.
     expect(renderEditable.cursorColor.alpha, 79);
     expect(renderEditable, paints..rrect(color: const Color(0x4f2196f3)));
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+  });
 
   testWidgets('Cursor does not animate on Android', (WidgetTester tester) async {
     const Widget widget = MaterialApp(
@@ -240,10 +241,11 @@ void main() {
     expect(renderEditable, paintsExactlyCountTimes(#drawRect, 0));
   });
 
-  testWidgets('Cursor does not animates when debugDeterministicCursor is set', (WidgetTester tester) async {
+  testWidgets('Cursor does not animates on iOS when debugDeterministicCursor is set', (WidgetTester tester) async {
     EditableText.debugDeterministicCursor = true;
-    const Widget widget = MaterialApp(
+    final Widget widget = MaterialApp(
-      home: Material(
+      theme: ThemeData(platform: TargetPlatform.iOS),
+      home: const Material(
         child: TextField(
           maxLines: 3,
         ),
@@ -275,7 +277,7 @@ void main() {
     expect(renderEditable, paints..rrect(color: const Color(0xff2196f3)));
 
     EditableText.debugDeterministicCursor = false;
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+  });
 
   testWidgets('Cursor does not animate on Android when debugDeterministicCursor is set', (WidgetTester tester) async {
     EditableText.debugDeterministicCursor = true;
@@ -344,9 +346,10 @@ void main() {
     expect(renderEditable, paintsExactlyCountTimes(#drawRect, 0));
   });
 
-  testWidgets('Cursor radius is 2.0', (WidgetTester tester) async {
+  testWidgets('Cursor radius is 2.0 on iOS', (WidgetTester tester) async {
-    const Widget widget = MaterialApp(
+    final Widget widget = MaterialApp(
-      home: Material(
+      theme: ThemeData(platform: TargetPlatform.iOS),
+      home: const Material(
         child: TextField(
           maxLines: 3,
         ),
@@ -358,7 +361,7 @@ void main() {
     final RenderEditable renderEditable = editableTextState.renderEditable;
 
     expect(renderEditable.cursorRadius, const Radius.circular(2.0));
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+  });
 
   testWidgets('Cursor gets placed correctly after going out of bounds', (WidgetTester tester) async {
     const String text = 'hello world this is fun and cool and awesome!';
@@ -642,7 +645,9 @@ void main() {
     expect(controller.selection.baseOffset, text.length);
   }, skip: isBrowser);
 
-  testWidgets('Floating cursor is painted', (WidgetTester tester) async {
+  testWidgets('Floating cursor is painted on iOS', (WidgetTester tester) async {
+    debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
+
     final TextEditingController controller = TextEditingController();
     const TextStyle textStyle = TextStyle();
     const String text = 'hello world this is fun and cool and awesome!';
@@ -651,6 +656,7 @@ void main() {
 
     await tester.pumpWidget(
       MaterialApp(
+        theme: ThemeData(platform: TargetPlatform.iOS),
         home: Padding(
           padding: const EdgeInsets.only(top: 0.25),
           child: Material(
@@ -725,13 +731,16 @@ void main() {
     editableTextState.updateFloatingCursor(RawFloatingCursorPoint(state: FloatingCursorDragState.End));
     await tester.pumpAndSettle();
     debugDefaultTargetPlatformOverride = null;
-  }, skip: isBrowser, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+  }, skip: isBrowser);
 
-  testWidgets('cursor layout', (WidgetTester tester) async {
+  testWidgets('cursor layout iOS', (WidgetTester tester) async {
     final GlobalKey<EditableTextState> editableTextKey = GlobalKey<EditableTextState>();
 
+    debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
+
     String changedValue;
     final Widget widget = MaterialApp(
+      theme: ThemeData(platform: TargetPlatform.iOS),
       home: RepaintBoundary(
         key: const ValueKey<int>(1),
         child: Column(
@@ -742,7 +751,7 @@ void main() {
               key: editableTextKey,
               controller: TextEditingController(),
               focusNode: FocusNode(),
-              style: Typography(platform: debugDefaultTargetPlatformOverride).black.subhead,
+              style: Typography(platform: TargetPlatform.iOS).black.subhead,
               cursorColor: Colors.blue,
               selectionControls: materialTextSelectionControls,
               keyboardType: TextInputType.text,
@@ -784,5 +793,6 @@ void main() {
       find.byKey(const ValueKey<int>(1)),
       matchesGoldenFile('editable_text_test.2.png'),
     );
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+    debugDefaultTargetPlatformOverride = null;
+  });
 }

packages/flutter/test/widgets/editable_text_test.dart

@@ -3757,7 +3757,9 @@ void main() {
   });
 
   // Regression test for https://github.com/flutter/flutter/issues/31287
-  testWidgets('text selection handle visibility', (WidgetTester tester) async {
+  testWidgets('iOS text selection handle visibility', (WidgetTester tester) async {
+    debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
+
     // Text with two separate words to select.
     const String testText = 'XXXXX          XXXXX';
     final TextEditingController controller = TextEditingController(text: testText);
@@ -3772,7 +3774,7 @@ void main() {
               showSelectionHandles: true,
               controller: controller,
               focusNode: FocusNode(),
-              style: Typography(platform: debugDefaultTargetPlatformOverride).black.subhead,
+              style: Typography(platform: TargetPlatform.iOS).black.subhead,
               cursorColor: Colors.blue,
               backgroundCursorColor: Colors.grey,
               selectionControls: cupertinoTextSelectionControls,
@@ -3922,7 +3924,9 @@ void main() {
     // at all. Again, both handles should be invisible.
     scrollable.controller.jumpTo(0);
     await verifyVisibility(HandlePositionInViewport.rightEdge, false, HandlePositionInViewport.rightEdge, false);
-  }, skip: isBrowser, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+
+    debugDefaultTargetPlatformOverride = null;
+  }, skip: isBrowser);
 
   testWidgets('scrolling doesn\'t bounce', (WidgetTester tester) async {
     // 3 lines of text, where the last line overflows and requires scrolling.

packages/flutter/test/widgets/flow_test.dart

@@ -150,9 +150,9 @@ void main() {
     ContainerLayer layer = RendererBinding.instance.renderView.debugLayer;
     while (layer != null && layer is! OpacityLayer)
       layer = layer.firstChild as ContainerLayer;
-    expect(layer, isA<OpacityLayer>());
+    expect(layer, isInstanceOf<OpacityLayer>());
     final OpacityLayer opacityLayer = layer as OpacityLayer;
     expect(opacityLayer.alpha, equals(opacity * 255));
-    expect(layer.firstChild, isA<TransformLayer>());
+    expect(layer.firstChild, isInstanceOf<TransformLayer>());
   });
 }

packages/flutter/test/widgets/heroes_test.dart

@@ -543,7 +543,7 @@ Future<void> main() async {
     final FlutterError error = exception as FlutterError;
     expect(error.diagnostics.length, 3);
     final DiagnosticsNode last = error.diagnostics.last;
-    expect(last, isA<DiagnosticsProperty<StatefulElement>>());
+    expect(last, isInstanceOf<DiagnosticsProperty<StatefulElement>>());
     expect(
       last.toStringDeep(),
       equalsIgnoringHashCodes(
@@ -1614,7 +1614,10 @@ Future<void> main() async {
 
   testWidgets('Heroes do not transition on back gestures by default', (WidgetTester tester) async {
     await tester.pumpWidget(MaterialApp(
-     routes: routes,
+      theme: ThemeData(
+        platform: TargetPlatform.iOS,
+      ),
+      routes: routes,
     ));
 
     expect(find.byKey(firstKey), isOnstage);
@@ -1649,11 +1652,14 @@ Future<void> main() async {
     expect(find.byKey(firstKey), isInCard);
     expect(find.byKey(secondKey), isOnstage);
     expect(find.byKey(secondKey), isInCard);
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+  });
 
   testWidgets('Heroes can transition on gesture in one frame', (WidgetTester tester) async {
     transitionFromUserGestures = true;
     await tester.pumpWidget(MaterialApp(
+      theme: ThemeData(
+        platform: TargetPlatform.iOS,
+      ),
       routes: routes,
     ));
 
@@ -1692,11 +1698,14 @@ Future<void> main() async {
     expect(find.byKey(firstKey), isOnstage);
     expect(find.byKey(firstKey), isInCard);
     expect(find.byKey(secondKey), findsNothing);
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+  });
 
   testWidgets('Heroes animate should hide destination hero and display original hero in case of dismissed', (WidgetTester tester) async {
     transitionFromUserGestures = true;
     await tester.pumpWidget(MaterialApp(
+      theme: ThemeData(
+        platform: TargetPlatform.iOS,
+      ),
       routes: routes,
     ));
 
@@ -1728,7 +1737,7 @@ Future<void> main() async {
     expect(find.byKey(firstKey), findsNothing);
     expect(find.byKey(secondKey), isOnstage);
     expect(find.byKey(secondKey), isInCard);
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+  });
 
   testWidgets('Handles transitions when a non-default initial route is set', (WidgetTester tester) async {
     await tester.pumpWidget(MaterialApp(
@@ -2289,6 +2298,9 @@ Future<void> main() async {
   testWidgets('Remove user gesture driven flights when the gesture is invalid', (WidgetTester tester) async {
     transitionFromUserGestures = true;
     await tester.pumpWidget(MaterialApp(
+      theme: ThemeData(
+        platform: TargetPlatform.iOS,
+      ),
       routes: routes,
     ));
 
@@ -2312,7 +2324,7 @@ Future<void> main() async {
     // The simple route should still be on top.
     expect(find.byKey(simpleKey), findsOneWidget);
     expect(tester.takeException(), isNull);
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+  });
 
   // Regression test for https://github.com/flutter/flutter/issues/40239.
   testWidgets(

packages/flutter/test/widgets/image_test.dart

@@ -1101,14 +1101,14 @@ void main() {
     expect(find.byType(Center), findsOneWidget);
     expect(find.byType(Padding), findsOneWidget);
     expect(find.byType(RawImage), findsOneWidget);
-    expect(tester.widget<Padding>(find.byType(Padding)).child, isA<RawImage>());
+    expect(tester.widget<Padding>(find.byType(Padding)).child, isInstanceOf<RawImage>());
     streamCompleter.setData(chunkEvent: const ImageChunkEvent(cumulativeBytesLoaded: 10, expectedTotalBytes: 100));
     await tester.pump();
     expect(find.byType(Center), findsOneWidget);
     expect(find.byType(Padding), findsOneWidget);
     expect(find.byType(RawImage), findsOneWidget);
-    expect(tester.widget<Center>(find.byType(Center)).child, isA<Padding>());
+    expect(tester.widget<Center>(find.byType(Center)).child, isInstanceOf<Padding>());
-    expect(tester.widget<Padding>(find.byType(Padding)).child, isA<RawImage>());
+    expect(tester.widget<Padding>(find.byType(Padding)).child, isInstanceOf<RawImage>());
   }, skip: isBrowser);
 
   testWidgets('Image state handles loadingBuilder update from null to non-null', (WidgetTester tester) async {

packages/flutter/test/widgets/list_wheel_scroll_view_test.dart

@@ -1203,6 +1203,8 @@ void main() {
     });
 
     testWidgets('high fling velocities lands exactly on items', (WidgetTester tester) async {
+      debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
+
       final FixedExtentScrollController controller = FixedExtentScrollController(initialItem: 40);
       final List<double> scrolledPositions = <double>[];
 
@@ -1250,7 +1252,9 @@ void main() {
       expect(controller.selectedItem, 49);
       // More importantly, lands tightly on 49.
       expect(scrolledPositions.last, moreOrLessEquals(49 * 100.0, epsilon: 0.3));
-    }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+
+      debugDefaultTargetPlatformOverride = null;
+    });
   });
 
   testWidgets('ListWheelScrollView getOffsetToReveal', (WidgetTester tester) async {

packages/flutter/test/widgets/media_query_test.dart

@@ -25,7 +25,7 @@ void main() {
     expect(exception ,isFlutterError);
     final FlutterError error = exception as FlutterError;
     expect(error.diagnostics.length, 3);
-    expect(error.diagnostics.last, isA<DiagnosticsProperty<Element>>());
+    expect(error.diagnostics.last, isInstanceOf<DiagnosticsProperty<Element>>());
     expect(
       error.toStringDeep(),
       equalsIgnoringHashCodes(

packages/flutter/test/widgets/modal_barrier_test.dart

@@ -340,6 +340,8 @@ void main() {
   });
 
   testWidgets('Dismissible ModalBarrier includes button in semantic tree on iOS', (WidgetTester tester) async {
+    debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
+
     final SemanticsTester semantics = SemanticsTester(tester);
     await tester.pumpWidget(const Directionality(
       textDirection: TextDirection.ltr,
@@ -362,7 +364,8 @@ void main() {
     expect(semantics, hasSemantics(expectedSemantics, ignoreId: true));
 
     semantics.dispose();
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+    debugDefaultTargetPlatformOverride = null;
+  });
 
   testWidgets('Dismissible ModalBarrier is hidden on Android (back button is used to dismiss)', (WidgetTester tester) async {
     final SemanticsTester semantics = SemanticsTester(tester);

packages/flutter/test/widgets/multichild_test.dart

@@ -13,12 +13,12 @@ void checkTree(WidgetTester tester, List<BoxDecoration> expectedDecorations) {
     (Element element) => element is MultiChildRenderObjectElement
   ));
   expect(element, isNotNull);
-  expect(element.renderObject, isA<RenderStack>());
+  expect(element.renderObject is RenderStack, isTrue);
   final RenderStack renderObject = element.renderObject as RenderStack;
   try {
     RenderObject child = renderObject.firstChild;
     for (final BoxDecoration decoration in expectedDecorations) {
-      expect(child, isA<RenderDecoratedBox>());
+      expect(child is RenderDecoratedBox, isTrue);
       final RenderDecoratedBox decoratedBox = child as RenderDecoratedBox;
       expect(decoratedBox.decoration, equals(decoration));
       final StackParentData decoratedBoxParentData = decoratedBox.parentData as StackParentData;

packages/flutter/test/widgets/navigator_test.dart

@@ -155,7 +155,7 @@ void main() {
     );
     await tester.pumpWidget(widget);
     await tester.tap(find.byKey(targetKey));
-    expect(exception, isFlutterError);
+    expect(exception, isInstanceOf<FlutterError>());
     expect('$exception', startsWith('Navigator operation requested with a context'));
   });
 
@@ -1027,7 +1027,7 @@ void main() {
     );
 
     final dynamic exception = tester.takeException();
-    expect(exception, isA<String>());
+    expect(exception is String, isTrue);
     expect(exception.startsWith('Could not navigate to initial route.'), isTrue);
 
     // Only the root route should've been pushed.
@@ -1048,7 +1048,7 @@ void main() {
       expect(exception, isFlutterError);
       final FlutterError error = exception as FlutterError;
       expect(error, isNotNull);
-      expect(error.diagnostics.last, isA<DiagnosticsProperty<NavigatorState>>());
+      expect(error.diagnostics.last, isInstanceOf<DiagnosticsProperty<NavigatorState>>());
       expect(
         error.toStringDeep(),
         equalsIgnoringHashCodes(
@@ -1075,7 +1075,7 @@ void main() {
       expect(exception, isFlutterError);
       final FlutterError error = exception as FlutterError;
       expect(error, isNotNull);
-      expect(error.diagnostics.last, isA<DiagnosticsProperty<NavigatorState>>());
+      expect(error.diagnostics.last, isInstanceOf<DiagnosticsProperty<NavigatorState>>());
       expect(
         error.toStringDeep(),
         equalsIgnoringHashCodes(

packages/flutter/test/widgets/nested_scroll_view_test.dart

@@ -113,6 +113,7 @@ Widget buildTest({ ScrollController controller, String title = 'TTTTTTTT' }) {
 
 void main() {
   testWidgets('NestedScrollView overscroll and release and hold', (WidgetTester tester) async {
+    debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
     await tester.pumpWidget(buildTest());
     expect(find.text('aaa2'), findsOneWidget);
     await tester.pump(const Duration(milliseconds: 250));
@@ -127,8 +128,10 @@ void main() {
     // TODO(ianh): Once we improve how we handle scrolling down from overscroll,
     // the following expectation should switch to 200.0.
     expect(tester.renderObject<RenderBox>(find.byType(AppBar)).size.height, 120.0);
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+    debugDefaultTargetPlatformOverride = null;
+  });
   testWidgets('NestedScrollView overscroll and release and hold', (WidgetTester tester) async {
+    debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
     await tester.pumpWidget(buildTest());
     expect(find.text('aaa2'), findsOneWidget);
     await tester.pump(const Duration(milliseconds: 250));
@@ -146,8 +149,10 @@ void main() {
     await tester.pump(const Duration(milliseconds: 10));
     expect(find.text('aaa2'), findsNothing);
     await tester.pump(const Duration(milliseconds: 1000));
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+    debugDefaultTargetPlatformOverride = null;
+  });
   testWidgets('NestedScrollView overscroll and release', (WidgetTester tester) async {
+    debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
     await tester.pumpWidget(buildTest());
     expect(find.text('aaa2'), findsOneWidget);
     await tester.pump(const Duration(milliseconds: 500));
@@ -159,10 +164,8 @@ void main() {
     await gesture1.up();
     await tester.pumpAndSettle();
     expect(find.text('aaa2'), findsOneWidget);
-  },
+    debugDefaultTargetPlatformOverride = null;
-  skip: true,  // https://github.com/flutter/flutter/issues/9040
+  }, skip: true); // https://github.com/flutter/flutter/issues/9040
-  variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
-
   testWidgets('NestedScrollView', (WidgetTester tester) async {
     await tester.pumpWidget(buildTest());
     expect(find.text('aaa2'), findsOneWidget);
@@ -607,11 +610,12 @@ void main() {
     debugDisableShadows = true;
   });
 
-  testWidgets('NestedScrollView and bouncing', (WidgetTester tester) async {
+  testWidgets('NestedScrollView and iOS bouncing', (WidgetTester tester) async {
     // This verifies that overscroll bouncing works correctly on iOS. For
     // example, this checks that if you pull to overscroll, friction is applied;
     // it also makes sure that if you scroll back the other way, the scroll
     // positions of the inner and outer list don't have a discontinuity.
+    debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
     const Key key1 = ValueKey<int>(1);
     const Key key2 = ValueKey<int>(2);
     await tester.pumpWidget(
@@ -670,7 +674,8 @@ void main() {
     await tester.pump();
     expect(tester.getRect(find.byKey(key1)), const Rect.fromLTWH(0.0, 0.0, 800.0, 100.0));
     await gesture.up();
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+    debugDefaultTargetPlatformOverride = null;
+  });
 }
 
 class TestHeader extends SliverPersistentHeaderDelegate {

packages/flutter/test/widgets/overlay_test.dart

@@ -634,9 +634,9 @@ void main() {
                 'The most common way to add an Overlay to an application is to\n'
                 'include a MaterialApp or Navigator widget in the runApp() call.\n',
               ));
-              expect(error.diagnostics[3], isA<DiagnosticsProperty<Widget>>());
+              expect(error.diagnostics[3], isInstanceOf<DiagnosticsProperty<Widget>>());
               expect(error.diagnostics[3].value, debugRequiredFor);
-              expect(error.diagnostics[4], isA<DiagnosticsProperty<Element>>());
+              expect(error.diagnostics[4], isInstanceOf<DiagnosticsProperty<Element>>());
               expect(error.toStringDeep(), equalsIgnoringHashCodes(
                 'FlutterError\n'
                 '   No Overlay widget found.\n'

packages/flutter/test/widgets/page_transitions_test.dart

@@ -157,7 +157,10 @@ void main() {
       ),
     };
 
-    await tester.pumpWidget(MaterialApp(routes: routes));
+    await tester.pumpWidget(MaterialApp(
+      routes: routes,
+      theme: ThemeData(platform: TargetPlatform.iOS),
+    ));
 
     Navigator.pushNamed(containerKey1.currentContext, '/settings');
 
@@ -196,7 +199,7 @@ void main() {
     settingsOffset = tester.getTopLeft(find.text('Settings'));
     expect(settingsOffset.dx, greaterThan(100.0));
     expect(settingsOffset.dy, 100.0);
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+  });
 
   testWidgets('Check back gesture doesn\'t start during transitions', (WidgetTester tester) async {
     final GlobalKey containerKey1 = GlobalKey();
@@ -206,7 +209,10 @@ void main() {
       '/settings': (_) => Scaffold(key: containerKey2, body: const Text('Settings')),
     };
 
-    await tester.pumpWidget(MaterialApp(routes: routes));
+    await tester.pumpWidget(MaterialApp(
+      routes: routes,
+      theme: ThemeData(platform: TargetPlatform.iOS),
+    ));
 
     Navigator.pushNamed(containerKey1.currentContext, '/settings');
 
@@ -239,7 +245,7 @@ void main() {
 
     expect(find.text('Home'), isOnstage);
     expect(find.text('Settings'), findsNothing);
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+  });
 
   // Tests bug https://github.com/flutter/flutter/issues/6451
   testWidgets('Check back gesture with a persistent bottom sheet showing', (WidgetTester tester) async {
@@ -250,7 +256,10 @@ void main() {
       '/sheet': (_) => PersistentBottomSheetTest(key: containerKey2),
     };
 
-    await tester.pumpWidget(MaterialApp(routes: routes));
+    await tester.pumpWidget(MaterialApp(
+      routes: routes,
+      theme: ThemeData(platform: TargetPlatform.iOS),
+    ));
 
     Navigator.pushNamed(containerKey1.currentContext, '/sheet');
 
@@ -293,7 +302,7 @@ void main() {
 
     // Sheet did not call setState (since the gesture did nothing).
     expect(sheet.setStateCalled, isFalse);
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+  });
 
   testWidgets('Test completed future', (WidgetTester tester) async {
     final Map<String, WidgetBuilder> routes = <String, WidgetBuilder>{

packages/flutter/test/widgets/page_view_test.dart

@@ -83,6 +83,7 @@ void main() {
 
   testWidgets('PageView does not squish when overscrolled', (WidgetTester tester) async {
     await tester.pumpWidget(MaterialApp(
+      theme: ThemeData(platform: TargetPlatform.iOS),
       home: PageView(
         children: List<Widget>.generate(10, (int i) {
           return Container(
@@ -112,7 +113,7 @@ void main() {
 
     expect(leftOf(0), lessThan(0.0));
     expect(sizeOf(0), equals(const Size(800.0, 600.0)));
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+  });
 
   testWidgets('PageController control test', (WidgetTester tester) async {
     final PageController controller = PageController(initialPage: 4);

packages/flutter/test/widgets/parent_data_test.dart

@@ -22,14 +22,14 @@ void checkTree(WidgetTester tester, List<TestParentData> expectedParentData) {
     find.byElementPredicate((Element element) => element is MultiChildRenderObjectElement)
   );
   expect(element, isNotNull);
-  expect(element.renderObject, isA<RenderStack>());
+  expect(element.renderObject is RenderStack, isTrue);
   final RenderStack renderObject = element.renderObject as RenderStack;
   try {
     RenderObject child = renderObject.firstChild;
     for (final TestParentData expected in expectedParentData) {
-      expect(child, isA<RenderDecoratedBox>());
+      expect(child is RenderDecoratedBox, isTrue);
       final RenderDecoratedBox decoratedBox = child as RenderDecoratedBox;
-      expect(decoratedBox.parentData, isA<StackParentData>());
+      expect(decoratedBox.parentData is StackParentData, isTrue);
       final StackParentData parentData = decoratedBox.parentData as StackParentData;
       expect(parentData.top, equals(expected.top));
       expect(parentData.right, equals(expected.right));

packages/flutter/test/widgets/physical_model_test.dart

@@ -105,7 +105,7 @@ void main() {
     );
 
     final dynamic exception = tester.takeException();
-    expect(exception, isFlutterError);
+    expect(exception, isInstanceOf<FlutterError>());
     expect(exception.diagnostics.first.level, DiagnosticLevel.summary);
     expect(exception.diagnostics.first.toString(), startsWith('A RenderFlex overflowed by '));
     await expectLater(

packages/flutter/test/widgets/platform_view_test.dart

@@ -128,7 +128,7 @@ void main() {
       );
 
       final Layer textureParentLayer = tester.layers[tester.layers.length - 2];
-      expect(textureParentLayer, isA<ClipRectLayer>());
+      expect(textureParentLayer, isInstanceOf<ClipRectLayer>());
       final ClipRectLayer clipRect = textureParentLayer as ClipRectLayer;
       expect(clipRect.clipRect, const Rect.fromLTWH(0.0, 0.0, 100.0, 50.0));
       expect(

packages/flutter/test/widgets/render_object_widget_test.dart

@@ -52,7 +52,7 @@ void main() {
     SingleChildRenderObjectElement element =
         tester.element(find.byElementType(SingleChildRenderObjectElement));
     expect(element, isNotNull);
-    expect(element.renderObject, isA<RenderDecoratedBox>());
+    expect(element.renderObject is RenderDecoratedBox, isTrue);
     RenderDecoratedBox renderObject = element.renderObject as RenderDecoratedBox;
     expect(renderObject.decoration, equals(kBoxDecorationA));
     expect(renderObject.position, equals(DecorationPosition.background));
@@ -60,7 +60,7 @@ void main() {
     await tester.pumpWidget(DecoratedBox(decoration: kBoxDecorationB));
     element = tester.element(find.byElementType(SingleChildRenderObjectElement));
     expect(element, isNotNull);
-    expect(element.renderObject, isA<RenderDecoratedBox>());
+    expect(element.renderObject is RenderDecoratedBox, isTrue);
     renderObject = element.renderObject as RenderDecoratedBox;
     expect(renderObject.decoration, equals(kBoxDecorationB));
     expect(renderObject.position, equals(DecorationPosition.background));
@@ -72,12 +72,12 @@ void main() {
       final SingleChildRenderObjectElement element =
           tester.firstElement(find.byElementType(SingleChildRenderObjectElement));
       expect(element, isNotNull);
-      expect(element.renderObject, isA<RenderDecoratedBox>());
+      expect(element.renderObject is RenderDecoratedBox, isTrue);
       final RenderDecoratedBox renderObject = element.renderObject as RenderDecoratedBox;
       expect(renderObject.decoration, equals(kBoxDecorationA));
       expect(renderObject.position, equals(DecorationPosition.background));
       expect(renderObject.child, isNotNull);
-      expect(renderObject.child, isA<RenderDecoratedBox>());
+      expect(renderObject.child is RenderDecoratedBox, isTrue);
       final RenderDecoratedBox child = renderObject.child as RenderDecoratedBox;
       expect(child.decoration, equals(kBoxDecorationB));
       expect(child.position, equals(DecorationPosition.background));
@@ -88,7 +88,7 @@ void main() {
       final SingleChildRenderObjectElement element =
           tester.element(find.byElementType(SingleChildRenderObjectElement));
       expect(element, isNotNull);
-      expect(element.renderObject, isA<RenderDecoratedBox>());
+      expect(element.renderObject is RenderDecoratedBox, isTrue);
       final RenderDecoratedBox renderObject = element.renderObject as RenderDecoratedBox;
       expect(renderObject.decoration, equals(kBoxDecorationA));
       expect(renderObject.position, equals(DecorationPosition.background));
@@ -164,12 +164,12 @@ void main() {
 
     SingleChildRenderObjectElement element =
         tester.firstElement(find.byElementType(SingleChildRenderObjectElement));
-    expect(element.renderObject, isA<RenderDecoratedBox>());
+    expect(element.renderObject is RenderDecoratedBox, isTrue);
     final RenderDecoratedBox parent = element.renderObject as RenderDecoratedBox;
-    expect(parent.child, isA<RenderDecoratedBox>());
+    expect(parent.child is RenderDecoratedBox, isTrue);
     final RenderDecoratedBox child = parent.child as RenderDecoratedBox;
     expect(child.decoration, equals(kBoxDecorationB));
-    expect(child.child, isA<RenderDecoratedBox>());
+    expect(child.child is RenderDecoratedBox, isTrue);
     final RenderDecoratedBox grandChild = child.child as RenderDecoratedBox;
     expect(grandChild.decoration, equals(kBoxDecorationC));
     expect(grandChild.child, isNull);
@@ -180,7 +180,7 @@ void main() {
 
     element =
         tester.element(find.byElementType(SingleChildRenderObjectElement));
-    expect(element.renderObject, isA<RenderDecoratedBox>());
+    expect(element.renderObject is RenderDecoratedBox, isTrue);
     expect(element.renderObject, equals(parent));
     expect(parent.child, isNull);
 

packages/flutter/test/widgets/routes_test.dart

@@ -48,7 +48,7 @@ class TestRoute extends Route<String> with LocalHistoryRoute<String> {
 
   @override
   void didReplace(Route<dynamic> oldRoute) {
-    expect(oldRoute, isA<TestRoute>());
+    expect(oldRoute, isInstanceOf<TestRoute>());
     final TestRoute castRoute = oldRoute as TestRoute;
     log('didReplace ${castRoute.name}');
     super.didReplace(castRoute);
@@ -65,7 +65,7 @@ class TestRoute extends Route<String> with LocalHistoryRoute<String> {
 
   @override
   void didPopNext(Route<dynamic> nextRoute) {
-    expect(nextRoute, isA<TestRoute>());
+    expect(nextRoute, isInstanceOf<TestRoute>());
     final TestRoute castRoute = nextRoute as TestRoute;
     log('didPopNext ${castRoute.name}');
     super.didPopNext(castRoute);
@@ -73,7 +73,7 @@ class TestRoute extends Route<String> with LocalHistoryRoute<String> {
 
   @override
   void didChangeNext(Route<dynamic> nextRoute) {
-    expect(nextRoute, anyOf(isNull, isA<TestRoute>()));
+    expect(nextRoute, anyOf(isNull, isInstanceOf<TestRoute>()));
     final TestRoute castRoute = nextRoute as TestRoute;
     log('didChangeNext ${castRoute?.name}');
     super.didChangeNext(castRoute);

packages/flutter/test/widgets/scroll_behavior_test.dart

@@ -47,7 +47,7 @@ void main() {
 
     expect(behavior, isNotNull);
     expect(behavior.flag, isTrue);
-    expect(position.physics, isA<ClampingScrollPhysics>());
+    expect(position.physics, isInstanceOf<ClampingScrollPhysics>());
     ScrollMetrics metrics = position.copyWith();
     expect(metrics.extentAfter, equals(400.0));
     expect(metrics.viewportDimension, equals(600.0));
@@ -62,7 +62,7 @@ void main() {
 
     expect(behavior, isNotNull);
     expect(behavior.flag, isFalse);
-    expect(position.physics, isA<BouncingScrollPhysics>());
+    expect(position.physics, isInstanceOf<BouncingScrollPhysics>());
     // Regression test for https://github.com/flutter/flutter/issues/5856
     metrics = position.copyWith();
     expect(metrics.extentAfter, equals(400.0));

packages/flutter/test/widgets/scroll_notification_test.dart

@@ -24,7 +24,7 @@ void main() {
 
     final TestGesture gesture = await tester.startGesture(const Offset(100.0, 100.0));
     await tester.pump(const Duration(seconds: 1));
-    expect(notification, isA<ScrollStartNotification>());
+    expect(notification, isInstanceOf<ScrollStartNotification>());
     expect(notification.depth, equals(0));
     final ScrollStartNotification start = notification as ScrollStartNotification;
     expect(start.dragDetails, isNotNull);
@@ -32,7 +32,7 @@ void main() {
 
     await gesture.moveBy(const Offset(-10.0, -10.0));
     await tester.pump(const Duration(seconds: 1));
-    expect(notification, isA<ScrollUpdateNotification>());
+    expect(notification, isInstanceOf<ScrollUpdateNotification>());
     expect(notification.depth, equals(0));
     final ScrollUpdateNotification update = notification as ScrollUpdateNotification;
     expect(update.dragDetails, isNotNull);
@@ -41,7 +41,7 @@ void main() {
 
     await gesture.up();
     await tester.pump(const Duration(seconds: 1));
-    expect(notification, isA<ScrollEndNotification>());
+    expect(notification, isInstanceOf<ScrollEndNotification>());
     expect(notification.depth, equals(0));
     final ScrollEndNotification end = notification as ScrollEndNotification;
     expect(end.dragDetails, isNotNull);

packages/flutter/test/widgets/scroll_physics_test.dart

@@ -239,10 +239,10 @@ void main() {
     } finally {
       expect(error, isNotNull);
       expect(error.diagnostics.length, 4);
-      expect(error.diagnostics[2], isA<DiagnosticsProperty<ScrollPhysics>>());
+      expect(error.diagnostics[2], isInstanceOf<DiagnosticsProperty<ScrollPhysics>>());
       expect(error.diagnostics[2].style, DiagnosticsTreeStyle.errorProperty);
       expect(error.diagnostics[2].value, physics);
-      expect(error.diagnostics[3], isA<DiagnosticsProperty<ScrollMetrics>>());
+      expect(error.diagnostics[3], isInstanceOf<DiagnosticsProperty<ScrollMetrics>>());
       expect(error.diagnostics[3].style, DiagnosticsTreeStyle.errorProperty);
       expect(error.diagnostics[3].value, position);
       // RegExp matcher is required here due to flutter web and flutter mobile generating

packages/flutter/test/widgets/scroll_view_test.dart

@@ -326,22 +326,22 @@ void main() {
 
   testWidgets('Primary ListViews are always scrollable', (WidgetTester tester) async {
     final ListView view = ListView(primary: true);
-    expect(view.physics, isA<AlwaysScrollableScrollPhysics>());
+    expect(view.physics, isInstanceOf<AlwaysScrollableScrollPhysics>());
   });
 
   testWidgets('Non-primary ListViews are not always scrollable', (WidgetTester tester) async {
     final ListView view = ListView(primary: false);
-    expect(view.physics, isNot(isA<AlwaysScrollableScrollPhysics>()));
+    expect(view.physics, isNot(isInstanceOf<AlwaysScrollableScrollPhysics>()));
   });
 
   testWidgets('Defaulting-to-primary ListViews are always scrollable', (WidgetTester tester) async {
     final ListView view = ListView(scrollDirection: Axis.vertical);
-    expect(view.physics, isA<AlwaysScrollableScrollPhysics>());
+    expect(view.physics, isInstanceOf<AlwaysScrollableScrollPhysics>());
   });
 
   testWidgets('Defaulting-to-not-primary ListViews are not always scrollable', (WidgetTester tester) async {
     final ListView view = ListView(scrollDirection: Axis.horizontal);
-    expect(view.physics, isNot(isA<AlwaysScrollableScrollPhysics>()));
+    expect(view.physics, isNot(isInstanceOf<AlwaysScrollableScrollPhysics>()));
   });
 
   testWidgets('primary:true leads to scrolling', (WidgetTester tester) async {
@@ -459,7 +459,7 @@ void main() {
 
     // A separatorBuilder that returns null throws a FlutterError
     await tester.pumpWidget(buildFrame(null));
-    expect(tester.takeException(), isFlutterError);
+    expect(tester.takeException(), isInstanceOf<FlutterError>());
     expect(find.byType(ErrorWidget), findsOneWidget);
   });
 
@@ -520,7 +520,7 @@ void main() {
 
     // When it does throw, one error widget is rendered in the item's place
     await tester.pumpWidget(buildFrame(true));
-    expect(tester.takeException(), isA<Exception>());
+    expect(tester.takeException(), isInstanceOf<Exception>());
     expect(finder, findsOneWidget);
   });
 
@@ -556,7 +556,7 @@ void main() {
 
     // When it does throw, one error widget is rendered in the separator's place
     await tester.pumpWidget(buildFrame(true));
-    expect(tester.takeException(), isA<Exception>());
+    expect(tester.takeException(), isInstanceOf<Exception>());
     expect(finder, findsOneWidget);
   });
 
@@ -566,7 +566,7 @@ void main() {
         return const SizedBox();
       },
       itemCount: -1,
-    ), throwsAssertionError);
+    ), throwsA(isInstanceOf<AssertionError>()));
   });
 
   testWidgets('ListView.builder asserts on negative semanticChildCount', (WidgetTester tester) async {
@@ -576,7 +576,7 @@ void main() {
       },
       itemCount: 1,
       semanticChildCount: -1,
-    ), throwsAssertionError);
+    ), throwsA(isInstanceOf<AssertionError>()));
   });
 
   testWidgets('ListView.builder asserts on nonsensical childCount/semanticChildCount', (WidgetTester tester) async {
@@ -586,6 +586,6 @@ void main() {
       },
       itemCount: 1,
       semanticChildCount: 4,
-    ), throwsAssertionError);
+    ), throwsA(isInstanceOf<AssertionError>()));
   });
 }

packages/flutter/test/widgets/scrollable_dispose_test.dart

@@ -28,9 +28,10 @@ void main() {
     await tester.pump(const Duration(hours: 5));
   });
 
-  testWidgets('Disposing a (nested) Scrollable while holding in overscroll does not crash', (WidgetTester tester) async {
+  testWidgets('Disposing a (nested) Scrollable while holding in overscroll (iOS) does not crash', (WidgetTester tester) async {
     // Regression test for https://github.com/flutter/flutter/issues/27707.
 
+    debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
     final ScrollController controller = ScrollController();
     final Key outterContainer = GlobalKey();
 
@@ -87,5 +88,7 @@ void main() {
     );
     await tester.pumpAndSettle();
     expect(controller.hasClients, isFalse);
-  }, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS,  TargetPlatform.macOS }));
+
+    debugDefaultTargetPlatformOverride = null;
+  });
 }