[web] Bootstrap tests without implicit view by default

lib/web_ui/lib/ui_web/src/ui_web/testing.dart

@@ -31,9 +31,9 @@ bool get debugEmulateFlutterTesterEnvironment =>
 set debugEmulateFlutterTesterEnvironment(bool value) {
   _debugEmulateFlutterTesterEnvironment = value;
   if (_debugEmulateFlutterTesterEnvironment) {
-    ensureImplicitViewInitialized();
     const ui.Size logicalSize = ui.Size(800.0, 600.0);
-    window.debugPhysicalSizeOverride = logicalSize * window.devicePixelRatio;
+    final EngineFlutterWindow? implicitView = EnginePlatformDispatcher.instance.implicitView;
+    implicitView?.debugPhysicalSizeOverride = logicalSize * implicitView.devicePixelRatio;
   }
   debugDisableFontFallbacks = value;
 }

lib/web_ui/test/canvaskit/backdrop_filter_golden_test.dart

@@ -17,7 +17,7 @@ const ui.Rect region = ui.Rect.fromLTRB(0, 0, 500, 500);
 
 void testMain() {
   group('BackdropFilter', () {
-    setUpCanvasKitTest();
+    setUpCanvasKitTest(withImplicitView: true);
     EngineFlutterDisplay.instance.debugOverrideDevicePixelRatio(1.0);
 
     test('blur renders to the edges', () async {

lib/web_ui/test/canvaskit/canvas_golden_test.dart

@@ -21,7 +21,7 @@ const ui.Rect kDefaultRegion = ui.Rect.fromLTRB(0, 0, 500, 250);
 
 void testMain() {
   group('CkCanvas', () {
-    setUpCanvasKitTest();
+    setUpCanvasKitTest(withImplicitView: true);
 
     setUp(() {
       renderer.fontCollection.debugResetFallbackFonts();

lib/web_ui/test/canvaskit/color_filter_golden_test.dart

@@ -17,7 +17,7 @@ const ui.Rect region = ui.Rect.fromLTRB(0, 0, 500, 250);
 
 void testMain() {
   group('ColorFilter', () {
-    setUpCanvasKitTest();
+    setUpCanvasKitTest(withImplicitView: true);
 
     test('ColorFilter.matrix applies a color filter', () async {
       final LayerSceneBuilder builder = LayerSceneBuilder();

lib/web_ui/test/canvaskit/common.dart

@@ -19,8 +19,9 @@ export '../common/rendering.dart' show renderScene;
 const MethodCodec codec = StandardMethodCodec();
 
 /// Common test setup for all CanvasKit unit-tests.
-void setUpCanvasKitTest() {
+void setUpCanvasKitTest({bool withImplicitView = false}) {
   setUpUnitTests(
+    withImplicitView: withImplicitView,
     emulateTesterEnvironment: false,
     setUpTestViewDimensions: false,
   );

lib/web_ui/test/canvaskit/display_canvas_factory_test.dart

@@ -30,7 +30,7 @@ class DummyDisplayCanvas extends DisplayCanvas {
 
 void testMain() {
   group('$DisplayCanvasFactory', () {
-    setUpCanvasKitTest();
+    setUpCanvasKitTest(withImplicitView: true);
 
     test('getCanvas', () {
       final DisplayCanvasFactory<DisplayCanvas> factory =

lib/web_ui/test/canvaskit/embedded_views_test.dart

@@ -25,7 +25,7 @@ void main() {
 
 void testMain() {
   group('$HtmlViewEmbedder', () {
-    setUpCanvasKitTest();
+    setUpCanvasKitTest(withImplicitView: true);
 
     setUp(() {
       EngineFlutterDisplay.instance.debugOverrideDevicePixelRatio(1);

lib/web_ui/test/canvaskit/filter_test.dart

@@ -49,7 +49,7 @@ void testMain() {
     return filters;
   }
 
-  setUpCanvasKitTest();
+  setUpCanvasKitTest(withImplicitView: true);
 
   group('ImageFilters', () {
     test('can be constructed', () {

lib/web_ui/test/canvaskit/flutter_tester_emulation_golden_test.dart

@@ -20,7 +20,7 @@ void testMain() {
   ui_web.debugEmulateFlutterTesterEnvironment = true;
 
   group('flutter_tester emulation', () {
-    setUpCanvasKitTest();
+    setUpCanvasKitTest(withImplicitView: true);
 
     test('defaults to FlutterTest font family',
         () async {

lib/web_ui/test/canvaskit/frame_timings_test.dart

@@ -14,7 +14,7 @@ void main() {
 
 void testMain() {
   group('frame timings', () {
-    setUpCanvasKitTest();
+    setUpCanvasKitTest(withImplicitView: true);
 
     test('collects frame timings', () async {
       await runFrameTimingsTest();

lib/web_ui/test/canvaskit/image_golden_test.dart

@@ -21,7 +21,7 @@ void main() {
 
 void testMain() {
   group('CanvasKit Images', () {
-    setUpCanvasKitTest();
+    setUpCanvasKitTest(withImplicitView: true);
 
     tearDown(() {
       mockHttpFetchResponseFactory = null;

lib/web_ui/test/canvaskit/layer_test.dart

@@ -17,7 +17,7 @@ void main() {
 
 void testMain() {
   group('CanvasKit', () {
-    setUpCanvasKitTest();
+    setUpCanvasKitTest(withImplicitView: true);
 
     // Regression test for https://github.com/flutter/flutter/issues/63715
     test('TransformLayer prerolls correctly', () async {

lib/web_ui/test/canvaskit/linear_gradient_golden_test.dart

@@ -19,7 +19,7 @@ const ui.Rect region = ui.Rect.fromLTRB(0, 0, 500, 250);
 
 void testMain() {
   group('Linear', () {
-    setUpCanvasKitTest();
+    setUpCanvasKitTest(withImplicitView: true);
 
     test('is correctly rendered', () async {
       final CkPictureRecorder recorder = CkPictureRecorder();

lib/web_ui/test/canvaskit/multi_view_test.dart

@@ -16,7 +16,7 @@ void main() {
 
 void testMain() {
   group('CanvasKit', () {
-    setUpCanvasKitTest();
+    setUpCanvasKitTest(withImplicitView: true);
 
     late LayerScene scene;
 

lib/web_ui/test/canvaskit/no_create_image_bitmap_test.dart

@@ -17,7 +17,7 @@ const ui.Rect region = ui.Rect.fromLTRB(0, 0, 500, 250);
 /// Test that we can render even if `createImageBitmap` is not supported.
 void testMain() {
   group('CanvasKit', () {
-    setUpCanvasKitTest();
+    setUpCanvasKitTest(withImplicitView: true);
     setUp(() async {
       EngineFlutterDisplay.instance.debugOverrideDevicePixelRatio(1.0);
     });

lib/web_ui/test/canvaskit/semantics_test.dart

@@ -22,7 +22,7 @@ void main() {
 // semantics.
 Future<void> testMain() async {
   group('CanvasKit semantics', () {
-    setUpCanvasKitTest();
+    setUpCanvasKitTest(withImplicitView: true);
 
     runSemanticsTests();
   });

lib/web_ui/test/canvaskit/shader_mask_golden_test.dart

@@ -18,7 +18,7 @@ const ui.Rect region = ui.Rect.fromLTRB(0, 0, 500, 250);
 
 void testMain() {
   group('ShaderMask', () {
-    setUpCanvasKitTest();
+    setUpCanvasKitTest(withImplicitView: true);
 
     test('Renders sweep gradient with color blend', () async {
       final LayerSceneBuilder builder = LayerSceneBuilder();

lib/web_ui/test/canvaskit/sweep_gradient_golden_test.dart

@@ -19,7 +19,7 @@ const ui.Rect region = ui.Rect.fromLTRB(0, 0, 500, 250);
 
 void testMain() {
   group('SweepGradient', () {
-    setUpCanvasKitTest();
+    setUpCanvasKitTest(withImplicitView: true);
 
     test('is correctly rendered', () async {
       final CkPictureRecorder recorder = CkPictureRecorder();

lib/web_ui/test/common/test_initialization.dart

@@ -14,34 +14,28 @@ import 'fake_asset_manager.dart';
 import 'rendering.dart';
 
 void setUpUnitTests({
+  bool withImplicitView = false,
   bool emulateTesterEnvironment = true,
   bool setUpTestViewDimensions = true,
 }) {
   late final FakeAssetScope debugFontsScope;
   setUpAll(() async {
-    // The implicit view is needed for `debugEmulateFlutterTesterEnvironment`,
-    // `flutterViewEmbedder`, and `debugPhysicalSizeOverride`.
-    engine.ensureImplicitViewInitialized();
-
     if (emulateTesterEnvironment) {
       ui_web.debugEmulateFlutterTesterEnvironment = true;
     }
 
     debugFontsScope = configureDebugFontsAssetScope(fakeAssetManager);
     debugOnlyAssetManager = fakeAssetManager;
-    await bootstrapAndRunApp();
+    await bootstrapAndRunApp(withImplicitView: withImplicitView);
     engine.renderer.fontCollection.fontFallbackManager?.downloadQueue.fallbackFontUrlPrefixOverride = 'assets/fallback_fonts/';
 
     if (setUpTestViewDimensions) {
-      // Force-initialize FlutterViewEmbedder so it doesn't overwrite test pixel ratio.
-      engine.ensureFlutterViewEmbedderInitialized();
-
       // The following parameters are hard-coded in Flutter's test embedder. Since
       // we don't have an embedder yet this is the lowest-most layer we can put
       // this stuff in.
       const double devicePixelRatio = 3.0;
       engine.EngineFlutterDisplay.instance.debugOverrideDevicePixelRatio(devicePixelRatio);
-      engine.EnginePlatformDispatcher.instance.implicitView!.debugPhysicalSizeOverride =
+      engine.EnginePlatformDispatcher.instance.implicitView?.debugPhysicalSizeOverride =
           const ui.Size(800 * devicePixelRatio, 600 * devicePixelRatio);
       engine.scheduleFrameCallback = () {};
     }
@@ -54,8 +48,21 @@ void setUpUnitTests({
   });
 }
 
-Future<void> bootstrapAndRunApp() async {
+Future<void> bootstrapAndRunApp({bool withImplicitView = false}) async {
   final Completer<void> completer = Completer<void>();
   await ui_web.bootstrapEngine(runApp: () => completer.complete());
   await completer.future;
+  if (!withImplicitView) {
+    _disableImplicitView();
+  }
+}
+
+void _disableImplicitView() {
+  // TODO(mdebbar): Instead of disabling the implicit view, we should be able to
+  //                initialize tests without an implicit view to begin with.
+  //                https://github.com/flutter/flutter/issues/138906
+  final engine.EngineFlutterWindow? implicitView = engine.EnginePlatformDispatcher.instance.implicitView;
+  if (implicitView != null) {
+    engine.EnginePlatformDispatcher.instance.viewManager.disposeAndUnregisterView(implicitView.viewId);
+  }
 }

lib/web_ui/test/engine/canvas_test.dart

@@ -16,7 +16,7 @@ void main() {
 }
 
 Future<void> testMain() async {
-  await bootstrapAndRunApp();
+  await bootstrapAndRunApp(withImplicitView: true);
 
   group('EngineCanvas', () {
     late MockEngineCanvas mockCanvas;

lib/web_ui/test/engine/composition_test.dart

@@ -48,7 +48,7 @@ GloballyPositionedTextEditingStrategy _enableEditingStrategy({
 }
 
 Future<void> testMain() async {
-  await bootstrapAndRunApp();
+  await bootstrapAndRunApp(withImplicitView: true);
 
   const String fakeComposingText = 'ImComposingText';
 

lib/web_ui/test/engine/history_test.dart

@@ -12,6 +12,7 @@ import 'package:ui/ui_web/src/ui_web.dart';
 
 import '../common/matchers.dart';
 import '../common/spy.dart';
+import '../common/test_initialization.dart';
 
 EngineFlutterWindow get implicitView =>
     EnginePlatformDispatcher.instance.implicitView!;
@@ -36,8 +37,8 @@ void main() {
 }
 
 void testMain() {
-  setUpAll(() {
-    ensureImplicitViewInitialized();
+  setUpAll(() async {
+    await bootstrapAndRunApp(withImplicitView: true);
   });
 
   test('createHistoryForExistingState', () {
@@ -745,7 +746,7 @@ void testMain() {
 
 Future<void> routeUpdated(String routeName) {
   final Completer<void> completer = Completer<void>();
-  implicitView.sendPlatformMessage(
+  EnginePlatformDispatcher.instance.sendPlatformMessage(
     'flutter/navigation',
     codec.encodeMethodCall(MethodCall(
       'routeUpdated',
@@ -758,7 +759,7 @@ Future<void> routeUpdated(String routeName) {
 
 Future<void> routeInformationUpdated(String location, dynamic state) {
   final Completer<void> completer = Completer<void>();
-  implicitView.sendPlatformMessage(
+  EnginePlatformDispatcher.instance.sendPlatformMessage(
     'flutter/navigation',
     codec.encodeMethodCall(MethodCall(
       'routeInformationUpdated',
@@ -771,7 +772,7 @@ Future<void> routeInformationUpdated(String location, dynamic state) {
 
 Future<void> systemNavigatorPop() {
   final Completer<void> completer = Completer<void>();
-  implicitView.sendPlatformMessage(
+  EnginePlatformDispatcher.instance.sendPlatformMessage(
     'flutter/platform',
     codec.encodeMethodCall(const MethodCall('SystemNavigator.pop')),
     (_) => completer.complete(),

lib/web_ui/test/engine/navigation_test.dart

@@ -3,50 +3,71 @@
 // found in the LICENSE file.
 
 import 'dart:async';
+import 'dart:typed_data';
 
 import 'package:test/bootstrap/browser.dart';
 import 'package:test/test.dart';
-import 'package:ui/src/engine.dart' as engine;
-import 'package:ui/src/engine/window.dart';
+import 'package:ui/src/engine.dart';
 import 'package:ui/ui.dart' as ui;
 
-const engine.MethodCodec codec = engine.JSONMethodCodec();
+import '../common/test_initialization.dart';
 
-engine.EngineFlutterWindow get implicitView =>
-    engine.EnginePlatformDispatcher.instance.implicitView!;
+const MethodCodec codec = JSONMethodCodec();
+
+EngineFlutterWindow get implicitView =>
+    EnginePlatformDispatcher.instance.implicitView!;
 
 void main() {
   internalBootstrapBrowserTest(() => testMain);
 }
 
 void testMain() {
-  engine.TestUrlStrategy? strategy;
+  group('without implicit view', () {
+    test('Handles navigation gracefully when no implicit view exists', () async {
+      expect(EnginePlatformDispatcher.instance.implicitView, isNull);
 
-  setUpAll(() {
-    ensureImplicitViewInitialized();
+      final Completer<ByteData?> completer = Completer<ByteData?>();
+      ui.PlatformDispatcher.instance.sendPlatformMessage(
+        'flutter/navigation',
+        codec.encodeMethodCall(const MethodCall(
+          'routeUpdated',
+          <String, dynamic>{'routeName': '/foo'},
+        )),
+        (ByteData? response) => completer.complete(response),
+      );
+      final ByteData? response = await completer.future;
+      expect(response, isNull);
+    });
   });
 
-  setUp(() async {
-    strategy = engine.TestUrlStrategy();
-    await implicitView.debugInitializeHistory(strategy, useSingle: true);
-  });
+  group('with implicit view', () {
+    late TestUrlStrategy strategy;
 
-  tearDown(() async {
-    strategy = null;
-    await implicitView.resetHistory();
-  });
+    setUpAll(() async {
+      await bootstrapAndRunApp(withImplicitView: true);
+    });
+
+    setUp(() async {
+      strategy = TestUrlStrategy();
+      await implicitView.debugInitializeHistory(strategy, useSingle: true);
+    });
+
+    tearDown(() async {
+      await implicitView.resetHistory();
+    });
 
-  test('Tracks pushed, replaced and popped routes', () async {
-    final Completer<void> completer = Completer<void>();
-    ui.PlatformDispatcher.instance.sendPlatformMessage(
-      'flutter/navigation',
-      codec.encodeMethodCall(const engine.MethodCall(
-        'routeUpdated',
-        <String, dynamic>{'routeName': '/foo'},
-      )),
-      (_) => completer.complete(),
-    );
-    await completer.future;
-    expect(strategy!.getPath(), '/foo');
+    test('Tracks pushed, replaced and popped routes', () async {
+      final Completer<void> completer = Completer<void>();
+      ui.PlatformDispatcher.instance.sendPlatformMessage(
+        'flutter/navigation',
+        codec.encodeMethodCall(const MethodCall(
+          'routeUpdated',
+          <String, dynamic>{'routeName': '/foo'},
+        )),
+        (_) => completer.complete(),
+      );
+      await completer.future;
+      expect(strategy.getPath(), '/foo');
+    });
   });
 }

lib/web_ui/test/engine/recording_canvas_test.dart

@@ -16,6 +16,7 @@ void main() {
 
 void testMain() {
   setUpUnitTests(
+    withImplicitView: true,
     setUpTestViewDimensions: false,
   );