`flutter test --wasm` support (#145347)

* Adds support for `flutter test --wasm`.
  * The test compilation flow is a bit different now, so that it supports compilers other than DDC. Specifically, when we run a set of unit tests, we generate a "switchboard" main function that imports each unit test and runs the main function for a specific one based off of a value set by the JS bootstrapping code. This way, there is one compile step and the same compile output is invoked for each unit test file.
* Also, removes all references to `dart:html` from flutter/flutter.
* Adds CI steps for running the framework unit tests with dart2wasm+skwasm
  * These steps are marked as `bringup: true`, so we don't know what kind of failures they will result in. Any failures they have will not block the tree at all yet while we're still in `bringup: true`. Once this PR is merged, I plan on looking at any failures and either fixing them or disabling them so we can get these CI steps running on presubmit.

This fixes https://github.com/flutter/flutter/issues/126692

.ci.yaml

@@ -1725,6 +1725,190 @@ targets:
       - bin/**
       - .ci.yaml
 
+  - name: Linux web_skwasm_tests_0
+    bringup: true
+    recipe: flutter/flutter_drone
+    timeout: 60
+    properties:
+      dependencies: >-
+        [
+          {"dependency": "android_sdk", "version": "version:34v3"},
+          {"dependency": "chrome_and_driver", "version": "version:119.0.6045.9"},
+          {"dependency": "goldctl", "version": "git_revision:720a542f6fe4f92922c3b8f0fdcc4d2ac6bb83cd"}
+        ]
+      shard: web_skwasm_tests
+      subshard: "0"
+      tags: >
+        ["framework", "hostonly", "shard", "linux"]
+      # Retry for flakes caused by https://github.com/flutter/flutter/issues/132654
+      presubmit_max_attempts: "2"
+    runIf:
+      - dev/**
+      - packages/**
+      - bin/**
+      - .ci.yaml
+
+  - name: Linux web_skwasm_tests_1
+    bringup: true
+    recipe: flutter/flutter_drone
+    timeout: 60
+    properties:
+      dependencies: >-
+        [
+          {"dependency": "android_sdk", "version": "version:34v3"},
+          {"dependency": "chrome_and_driver", "version": "version:119.0.6045.9"},
+          {"dependency": "goldctl", "version": "git_revision:720a542f6fe4f92922c3b8f0fdcc4d2ac6bb83cd"}
+        ]
+      shard: web_skwasm_tests
+      subshard: "1"
+      tags: >
+        ["framework", "hostonly", "shard", "linux"]
+      # Retry for flakes caused by https://github.com/flutter/flutter/issues/132654
+      presubmit_max_attempts: "2"
+    runIf:
+      - dev/**
+      - packages/**
+      - bin/**
+      - .ci.yaml
+
+  - name: Linux web_skwasm_tests_2
+    bringup: true
+    recipe: flutter/flutter_drone
+    timeout: 60
+    properties:
+      dependencies: >-
+        [
+          {"dependency": "android_sdk", "version": "version:34v3"},
+          {"dependency": "chrome_and_driver", "version": "version:119.0.6045.9"},
+          {"dependency": "goldctl", "version": "git_revision:720a542f6fe4f92922c3b8f0fdcc4d2ac6bb83cd"}
+        ]
+      shard: web_skwasm_tests
+      subshard: "2"
+      tags: >
+        ["framework", "hostonly", "shard", "linux"]
+      # Retry for flakes caused by https://github.com/flutter/flutter/issues/132654
+      presubmit_max_attempts: "2"
+    runIf:
+      - dev/**
+      - packages/**
+      - bin/**
+      - .ci.yaml
+
+  - name: Linux web_skwasm_tests_3
+    bringup: true
+    recipe: flutter/flutter_drone
+    timeout: 60
+    properties:
+      dependencies: >-
+        [
+          {"dependency": "android_sdk", "version": "version:34v3"},
+          {"dependency": "chrome_and_driver", "version": "version:119.0.6045.9"},
+          {"dependency": "goldctl", "version": "git_revision:720a542f6fe4f92922c3b8f0fdcc4d2ac6bb83cd"}
+        ]
+      shard: web_skwasm_tests
+      subshard: "3"
+      tags: >
+        ["framework", "hostonly", "shard", "linux"]
+      # Retry for flakes caused by https://github.com/flutter/flutter/issues/132654
+      presubmit_max_attempts: "2"
+    runIf:
+      - dev/**
+      - packages/**
+      - bin/**
+      - .ci.yaml
+
+  - name: Linux web_skwasm_tests_4
+    bringup: true
+    recipe: flutter/flutter_drone
+    timeout: 60
+    properties:
+      dependencies: >-
+        [
+          {"dependency": "android_sdk", "version": "version:34v3"},
+          {"dependency": "chrome_and_driver", "version": "version:119.0.6045.9"},
+          {"dependency": "goldctl", "version": "git_revision:720a542f6fe4f92922c3b8f0fdcc4d2ac6bb83cd"}
+        ]
+      shard: web_skwasm_tests
+      subshard: "4"
+      tags: >
+        ["framework", "hostonly", "shard", "linux"]
+      # Retry for flakes caused by https://github.com/flutter/flutter/issues/132654
+      presubmit_max_attempts: "2"
+    runIf:
+      - dev/**
+      - packages/**
+      - bin/**
+      - .ci.yaml
+
+  - name: Linux web_skwasm_tests_5
+    bringup: true
+    recipe: flutter/flutter_drone
+    timeout: 60
+    properties:
+      dependencies: >-
+        [
+          {"dependency": "android_sdk", "version": "version:34v3"},
+          {"dependency": "chrome_and_driver", "version": "version:119.0.6045.9"},
+          {"dependency": "goldctl", "version": "git_revision:720a542f6fe4f92922c3b8f0fdcc4d2ac6bb83cd"}
+        ]
+      shard: web_skwasm_tests
+      subshard: "5"
+      tags: >
+        ["framework", "hostonly", "shard", "linux"]
+      # Retry for flakes caused by https://github.com/flutter/flutter/issues/132654
+      presubmit_max_attempts: "2"
+    runIf:
+      - dev/**
+      - packages/**
+      - bin/**
+      - .ci.yaml
+
+  - name: Linux web_skwasm_tests_6
+    bringup: true
+    recipe: flutter/flutter_drone
+    timeout: 60
+    properties:
+      dependencies: >-
+        [
+          {"dependency": "android_sdk", "version": "version:34v3"},
+          {"dependency": "chrome_and_driver", "version": "version:119.0.6045.9"},
+          {"dependency": "goldctl", "version": "git_revision:720a542f6fe4f92922c3b8f0fdcc4d2ac6bb83cd"}
+        ]
+      shard: web_skwasm_tests
+      subshard: "6"
+      tags: >
+        ["framework", "hostonly", "shard", "linux"]
+      # Retry for flakes caused by https://github.com/flutter/flutter/issues/132654
+      presubmit_max_attempts: "2"
+    runIf:
+      - dev/**
+      - packages/**
+      - bin/**
+      - .ci.yaml
+
+  - name: Linux web_skwasm_tests_7_last
+    bringup: true
+    recipe: flutter/flutter_drone
+    timeout: 60
+    properties:
+      dependencies: >-
+        [
+          {"dependency": "android_sdk", "version": "version:34v3"},
+          {"dependency": "chrome_and_driver", "version": "version:119.0.6045.9"},
+          {"dependency": "goldctl", "version": "git_revision:720a542f6fe4f92922c3b8f0fdcc4d2ac6bb83cd"}
+        ]
+      shard: web_skwasm_tests
+      subshard: "7_last"
+      tags: >
+        ["framework", "hostonly", "shard", "linux"]
+      # Retry for flakes caused by https://github.com/flutter/flutter/issues/132654
+      presubmit_max_attempts: "2"
+    runIf:
+      - dev/**
+      - packages/**
+      - bin/**
+      - .ci.yaml
+
   - name: Linux web_tool_tests
     recipe: flutter/flutter_drone
     timeout: 60

TESTOWNERS

@@ -286,7 +286,7 @@
 /dev/devicelab/bin/tasks/technical_debt__cost.dart @HansMuller @flutter/framework
 /dev/devicelab/bin/tasks/web_benchmarks_canvaskit.dart @yjbanov @flutter/web
 /dev/devicelab/bin/tasks/web_benchmarks_html.dart @yjbanov @flutter/web
-/dev/devicelab/bin/tasks/web_benchmarks_skwasm.dart @jacksongardner @flutter/web
+/dev/devicelab/bin/tasks/web_benchmarks_skwasm.dart @eyebrowsoffire @flutter/web
 /dev/devicelab/bin/tasks/windows_home_scroll_perf__timeline_summary.dart @jonahwilliams @flutter/engine
 /dev/devicelab/bin/tasks/windows_startup_test.dart @loic-sharma @flutter/desktop
 
@@ -325,7 +325,7 @@
 # flutter_plugins @stuartmorgan @flutter/plugin
 # framework_tests @HansMuller @flutter/framework
 # fuchsia_precache @christopherfujino @flutter/tool
-# realm_checker @jacksongardner @flutter/tool
+# realm_checker @eyebrowsoffire @flutter/tool
 # skp_generator @Hixie
 # test_ownership @keyonghan
 # tool_host_cross_arch_tests @andrewkolos @flutter/tool
@@ -336,4 +336,5 @@
 # web_integration_tests @yjbanov @flutter/web
 # web_long_running_tests @yjbanov @flutter/web
 # web_tests @yjbanov @flutter/web
+# web_skwasm_tests @eyebrowsoffire @flutter/web
 # web_tool_tests @eliasyishak @flutter/tool

dev/bots/test.dart

@@ -242,6 +242,8 @@ Future<void> main(List<String> args) async {
       'web_tests': _runWebHtmlUnitTests,
       // All the unit/widget tests run using `flutter test --platform=chrome --web-renderer=canvaskit`
       'web_canvaskit_tests': _runWebCanvasKitUnitTests,
+      // All the unit/widget tests run using `flutter test --platform=chrome --wasm --web-renderer=skwasm`
+      'web_skwasm_tests': _runWebSkwasmUnitTests,
       // All web integration tests
       'web_long_running_tests': _runWebLongRunningTests,
       'flutter_plugins': _runFlutterPackagesTests,
@@ -1117,14 +1119,18 @@ Future<void> _runFrameworkCoverage() async {
 }
 
 Future<void> _runWebHtmlUnitTests() {
-  return _runWebUnitTests('html');
+  return _runWebUnitTests('html', false);
 }
 
 Future<void> _runWebCanvasKitUnitTests() {
-  return _runWebUnitTests('canvaskit');
+  return _runWebUnitTests('canvaskit', false);
 }
 
-Future<void> _runWebUnitTests(String webRenderer) async {
+Future<void> _runWebSkwasmUnitTests() {
+  return _runWebUnitTests('skwasm', true);
+}
+
+Future<void> _runWebUnitTests(String webRenderer, bool useWasm) async {
   final Map<String, ShardRunner> subshards = <String, ShardRunner>{};
 
   final Directory flutterPackageDirectory = Directory(path.join(flutterRoot, 'packages', 'flutter'));
@@ -1160,6 +1166,7 @@ Future<void> _runWebUnitTests(String webRenderer) async {
         index * testsPerShard,
         (index + 1) * testsPerShard,
       ),
+      useWasm,
     );
   }
 
@@ -1175,16 +1182,19 @@ Future<void> _runWebUnitTests(String webRenderer) async {
         (webShardCount - 1) * testsPerShard,
         allTests.length,
       ),
+      useWasm,
     );
     await _runFlutterWebTest(
       webRenderer,
       path.join(flutterRoot, 'packages', 'flutter_web_plugins'),
       <String>['test'],
+      useWasm,
     );
     await _runFlutterWebTest(
       webRenderer,
       path.join(flutterRoot, 'packages', 'flutter_driver'),
       <String>[path.join('test', 'src', 'web_tests', 'web_extension_test.dart')],
+      useWasm,
     );
   };
 
@@ -1333,11 +1343,19 @@ Future<void> _runWebLongRunningTests() async {
       'html',
       path.join(flutterRoot, 'packages', 'integration_test'),
       <String>['test/web_extension_test.dart'],
+      false,
     ),
     () => _runFlutterWebTest(
       'canvaskit',
       path.join(flutterRoot, 'packages', 'integration_test'),
       <String>['test/web_extension_test.dart'],
+      false,
+    ),
+    () => _runFlutterWebTest(
+      'skwasm',
+      path.join(flutterRoot, 'packages', 'integration_test'),
+      <String>['test/web_extension_test.dart'],
+      true,
     ),
   ];
 
@@ -2302,13 +2320,19 @@ Future<void> _runWebDebugTest(String target, {
   }
 }
 
-Future<void> _runFlutterWebTest(String webRenderer, String workingDirectory, List<String> tests) async {
+Future<void> _runFlutterWebTest(
+  String webRenderer,
+  String workingDirectory,
+  List<String> tests,
+  bool useWasm,
+) async {
   await runCommand(
     flutter,
     <String>[
       'test',
       '-v',
       '--platform=chrome',
+      if (useWasm) '--wasm',
       '--web-renderer=$webRenderer',
       '--dart-define=DART_HHH_BOT=$_runningInDartHHHBot',
       ...flutterTestArgs,

dev/integration_tests/web/lib/framework_stack_trace.dart

@@ -2,11 +2,12 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:html' as html;
+import 'dart:js_interop';
 
 import 'package:flutter/foundation.dart';
 import 'package:flutter/widgets.dart';
 import 'package:meta/dart2js.dart';
+import 'package:web/web.dart' as web;
 
 // Tests that the framework prints stack traces in all build modes.
 //
@@ -35,10 +36,12 @@ Future<void> main() async {
   }
 
   print(output);
-  html.HttpRequest.request(
-    '/test-result',
-    method: 'POST',
-    sendData: '$output',
+  web.window.fetch(
+    '/test-result'.toJS,
+    web.RequestInit(
+      method: 'POST',
+      body: '$output'.toJS,
+    )
   );
 }
 

dev/integration_tests/web/lib/service_worker_test.dart

@@ -2,10 +2,13 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:html' as html;
+import 'dart:js_interop';
+
+import 'package:web/web.dart' as web;
+
 Future<void> main() async {
-  await html.window.navigator.serviceWorker?.ready;
-  const String response = 'CLOSE?version=1';
-  await html.HttpRequest.getString(response);
-  html.document.body?.appendHtml(response);
+  await web.window.navigator.serviceWorker.ready.toDart;
+  final JSString response = 'CLOSE?version=1'.toJS;
+  await web.window.fetch(response).toDart;
+  web.document.body?.append(response);
 }

dev/integration_tests/web/lib/service_worker_test_blocked_service_workers.dart

@@ -2,9 +2,12 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:html' as html;
+import 'dart:js_interop';
+
+import 'package:web/web.dart' as web;
+
 Future<void> main() async {
-  const String response = 'CLOSE?version=1';
-  await html.HttpRequest.getString(response);
-  html.document.body?.appendHtml(response);
+  final JSString response = 'CLOSE?version=1'.toJS;
+  await web.window.fetch(response).toDart;
+  web.document.body?.append(response);
 }

dev/integration_tests/web/lib/sound_mode.dart

@@ -4,7 +4,9 @@
 
 // @dart = 2.12
 
-import 'dart:html' as html;
+import 'dart:js_interop';
+
+import 'package:web/web.dart' as web;
 
 // Verify that web applications can be run in sound mode.
 void main() {
@@ -16,9 +18,11 @@ void main() {
     output = '--- TEST SUCCEEDED ---';
   }
   print(output);
-  html.HttpRequest.request(
-    '/test-result',
-    method: 'POST',
-    sendData: output,
+  web.window.fetch(
+    '/test-result'.toJS,
+    web.RequestInit(
+      method: 'POST',
+      body: output.toJS,
+    )
   );
 }

dev/integration_tests/web/lib/stack_trace.dart

@@ -2,11 +2,12 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:html' as html;
+import 'dart:js_interop';
 
 import 'package:collection/collection.dart';
 import 'package:flutter/foundation.dart';
 import 'package:meta/dart2js.dart';
+import 'package:web/web.dart' as web;
 
 /// Expected sequence of method calls.
 const List<String> callChain = <String>['baz', 'bar', 'foo'];
@@ -32,7 +33,7 @@ const List<StackFrame> expectedDebugStackFrames = <StackFrame>[
     packageScheme: 'package',
     package: 'packages',
     packagePath: 'web_integration/stack_trace.dart',
-    line: 119,
+    line: 122,
     column: 3,
     className: '<unknown>',
     method: 'baz',
@@ -43,7 +44,7 @@ const List<StackFrame> expectedDebugStackFrames = <StackFrame>[
     packageScheme: 'package',
     package: 'packages',
     packagePath: 'web_integration/stack_trace.dart',
-    line: 114,
+    line: 117,
     column: 3,
     className: '<unknown>',
     method: 'bar',
@@ -54,7 +55,7 @@ const List<StackFrame> expectedDebugStackFrames = <StackFrame>[
     packageScheme: 'package',
     package: 'packages',
     packagePath: 'web_integration/stack_trace.dart',
-    line: 109,
+    line: 112,
     column: 3,
     className: '<unknown>',
     method: 'foo',
@@ -97,10 +98,12 @@ void main() {
     output.writeln('--- TEST FAILED ---');
   }
   print(output);
-  html.HttpRequest.request(
-    '/test-result',
-    method: 'POST',
-    sendData: '$output',
+  web.window.fetch(
+    '/test-result'.toJS,
+    web.RequestInit(
+      method: 'POST',
+      body: '$output'.toJS,
+    )
   );
 }
 

dev/integration_tests/web/lib/web_define_loading.dart

@@ -2,7 +2,9 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:html' as html;
+import 'dart:js_interop';
+
+import 'package:web/web.dart' as web;
 
 Future<void> main() async {
   final StringBuffer output = StringBuffer();
@@ -16,9 +18,11 @@ Future<void> main() async {
     print('--- TEST FAILED ---');
   }
 
-  html.HttpRequest.request(
-    '/test-result',
-    method: 'POST',
-    sendData: '$output',
+  web.window.fetch(
+    '/test-result'.toJS,
+    web.RequestInit(
+      method: 'POST',
+      body: '$output'.toJS,
+    )
   );
 }

dev/integration_tests/web/lib/web_directory_loading.dart

@@ -2,16 +2,20 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:html' as html;
+import 'dart:js_interop';
+
+import 'package:web/web.dart' as web;
 
 // Attempt to load a file that is hosted in the applications's `web/` directory.
 Future<void> main() async {
   try {
-    final html.HttpRequest request = await html.HttpRequest.request(
-      '/example',
-      method: 'GET',
-    );
-    final String? body = request.responseText;
+    final web.Response response = await web.window.fetch(
+      '/example'.toJS,
+      web.RequestInit(
+        method: 'GET',
+      ),
+    ).toDart;
+    final String body = (await response.text().toDart).toDart;
     if (body == 'This is an Example') {
       print('--- TEST SUCCEEDED ---');
     } else {

dev/integration_tests/web/lib/web_resources_cdn_test.dart

@@ -2,7 +2,9 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:html' as html;
+import 'dart:js_interop';
+
+import 'package:web/web.dart' as web;
 
 // Attempt to load CanvasKit resources hosted on gstatic.
 Future<void> main() async {
@@ -12,12 +14,13 @@ Future<void> main() async {
     return;
   }
   try {
-    final html.HttpRequest request = await html.HttpRequest.request(
-      'https://www.gstatic.com/flutter-canvaskit/$engineVersion/canvaskit.js',
-      method: 'GET',
-    );
-    final dynamic response = request.response;
-    if (response != null) {
+    final web.Response response = await web.window.fetch(
+      'https://www.gstatic.com/flutter-canvaskit/$engineVersion/canvaskit.js'.toJS,
+      web.RequestInit(
+        method: 'GET',
+      ),
+    ).toDart;
+    if (response.ok) {
       print('--- TEST SUCCEEDED ---');
     } else {
       print('--- TEST FAILED ---');
@@ -27,12 +30,13 @@ Future<void> main() async {
     print('--- TEST FAILED ---');
   }
   try {
-    final html.HttpRequest request = await html.HttpRequest.request(
-      'https://www.gstatic.com/flutter-canvaskit/$engineVersion/canvaskit.wasm',
-      method: 'GET',
-    );
-    final dynamic response = request.response;
-    if (response != null) {
+    final web.Response response = await web.window.fetch(
+      'https://www.gstatic.com/flutter-canvaskit/$engineVersion/canvaskit.wasm'.toJS,
+      web.RequestInit(
+        method: 'GET',
+      )
+    ).toDart;
+    if (response.ok) {
       print('--- TEST SUCCEEDED ---');
     } else {
       print('--- TEST FAILED ---');

dev/integration_tests/web/pubspec.yaml

@@ -14,10 +14,12 @@ dependencies:
   flutter:
     sdk: flutter
 
+  web: 0.5.1
+
   characters: 1.3.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   collection: 1.18.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   material_color_utilities: 0.8.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   meta: 1.12.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   vector_math: 2.1.4 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
 
-# PUBSPEC CHECKSUM: 6f95
+# PUBSPEC CHECKSUM: 8d22

dev/integration_tests/web/test/test.dart

@@ -5,7 +5,7 @@
 import 'package:web_integration/a.dart'
   if (dart.library.io) 'package:web_integration/b.dart' as message1;
 import 'package:web_integration/c.dart'
-  if (dart.library.html) 'package:web_integration/d.dart' as message2;
+  if (dart.library.js_interop) 'package:web_integration/d.dart' as message2;
 
 void main() {
   if (message1.message == 'a' && message2.message == 'd')  {

dev/integration_tests/web_e2e_tests/lib/common.dart

@@ -2,12 +2,11 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:html';
-
 import 'package:flutter_test/flutter_test.dart';
+import 'package:web/web.dart' as web;
 
 /// Whether the current browser is Firefox.
-bool get isFirefox => window.navigator.userAgent.toLowerCase().contains('firefox');
+bool get isFirefox => web.window.navigator.userAgent.toLowerCase().contains('firefox');
 
 /// Finds elements in the DOM tree rendered by the Flutter Web engine.
 ///
@@ -15,8 +14,8 @@ bool get isFirefox => window.navigator.userAgent.toLowerCase().contains('firefox
 /// `<flt-glass-pane>` element. Otherwise, looks under `<flt-glass-pane>`
 /// without penetrating the shadow DOM. In the latter case, if the application
 /// creates platform views, this will also find platform view elements.
-List<Node> findElements(String selector) {
-  final Element? flutterView = document.querySelector('flutter-view');
+web.NodeList findElements(String selector) {
+  final web.Element? flutterView = web.document.querySelector('flutter-view');
 
   if (flutterView == null) {
     fail(

dev/integration_tests/web_e2e_tests/lib/scroll_wheel_main.dart

@@ -2,10 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:html' as html;
-
 import 'package:flutter/material.dart';
 
+import 'package:web/web.dart' as web;
+
 void main() => runApp(const MyApp());
 
 class MyApp extends StatelessWidget {
@@ -79,29 +79,25 @@ abstract class DeltaMode {
 
 void dispatchMouseWheelEvent(int mouseX, int mouseY,
     int deltaMode, double deltaX, double deltaY) {
-  final html.EventTarget target = html.document.elementFromPoint(mouseX, mouseY)!;
+  final web.EventTarget target = web.document.elementFromPoint(mouseX, mouseY)!;
 
-  target.dispatchEvent(html.MouseEvent('mouseover',
+  target.dispatchEvent(web.MouseEvent('mouseover', web.MouseEventInit(
     screenX: mouseX,
     screenY: mouseY,
     clientX: mouseX,
     clientY: mouseY,
-  ));
+  )));
 
-  target.dispatchEvent(html.MouseEvent('mousemove',
+  target.dispatchEvent(web.MouseEvent('mousemove', web.MouseEventInit(
     screenX: mouseX,
     screenY: mouseY,
     clientX: mouseX,
     clientY: mouseY,
-  ));
+  )));
 
-  target.dispatchEvent(html.WheelEvent('wheel',
-    screenX: mouseX,
-    screenY: mouseY,
-    clientX: mouseX,
-    clientY: mouseY,
+  target.dispatchEvent(web.WheelEvent('wheel', web.WheelEventInit(
     deltaMode: deltaMode,
     deltaX : deltaX,
     deltaY : deltaY,
-  ));
+  )));
 }

dev/integration_tests/web_e2e_tests/pubspec.yaml

@@ -21,6 +21,7 @@ dependencies:
   integration_test:
     sdk: flutter
   flutter_gallery_assets: 1.0.2
+  web: 0.5.1
 
   async: 2.11.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   boolean_selector: 2.1.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -82,7 +83,6 @@ dev_dependencies:
   test_core: 0.6.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   typed_data: 1.3.2 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   watcher: 1.1.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
-  web: 0.5.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   web_socket_channel: 2.4.4 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   webkit_inspection_protocol: 1.2.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   yaml: 3.1.2 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"

dev/integration_tests/web_e2e_tests/test_driver/platform_messages_integration.dart

@@ -2,13 +2,13 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:html' as html;
 import 'dart:ui_web' as ui_web;
 
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:integration_test/integration_test.dart';
+import 'package:web/web.dart' as web;
 import 'package:web_e2e_tests/platform_messages_main.dart' as app;
 
 void main() {
@@ -27,7 +27,7 @@ void main() {
     await tester.tap(find.byKey(const Key('input')));
     // Focus in input, otherwise clipboard will fail with
     // 'document is not focused' platform exception.
-    html.document.querySelector('input')?.focus();
+    (web.document.querySelector('input') as web.HTMLElement?)?.focus();
     await Clipboard.setData(const ClipboardData(text: 'sample text'));
   }, skip: true); // https://github.com/flutter/flutter/issues/54296
 
@@ -38,7 +38,7 @@ void main() {
     platformViewsRegistry.getNextPlatformViewId();
     ui_web.platformViewRegistry.registerViewFactory('MyView', (int viewId) {
       viewInstanceCount += 1;
-      return html.DivElement();
+      return web.HTMLDivElement();
     });
 
     app.main();

dev/integration_tests/web_e2e_tests/test_driver/text_editing_integration.dart

@@ -2,13 +2,13 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:html';
 import 'dart:js_util' as js_util;
 
 import 'package:flutter/gestures.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:integration_test/integration_test.dart';
+import 'package:web/web.dart' as web;
 import 'package:web_e2e_tests/common.dart';
 import 'package:web_e2e_tests/text_editing_main.dart' as app;
 
@@ -26,9 +26,9 @@ void main() {
     await tester.tap(find.byKey(const Key('input')));
 
     // A native input element will be appended to the DOM.
-    final List<Node> nodeList = findElements('input');
+    final web.NodeList nodeList = findElements('input');
     expect(nodeList.length, equals(1));
-    final InputElement input = nodeList[0] as InputElement;
+    final web.HTMLInputElement input = nodeList.item(0)! as web.HTMLInputElement;
     // The element's value will be the same as the textFormField's value.
     expect(input.value, 'Text1');
 
@@ -50,9 +50,9 @@ void main() {
     await tester.tap(find.byKey(const Key('empty-input')));
 
     // A native input element will be appended to the DOM.
-    final List<Node> nodeList = findElements('input');
+    final web.NodeList nodeList = findElements('input');
     expect(nodeList.length, equals(1));
-    final InputElement input = nodeList[0] as InputElement;
+    final web.HTMLInputElement input = nodeList.item(0)! as web.HTMLInputElement;
     // The element's value will be empty.
     expect(input.value, '');
 
@@ -81,7 +81,7 @@ void main() {
     await tester.tap(find.byKey(const Key('input2')));
 
     // Press Tab. This should trigger `onFieldSubmitted` of TextField.
-    final InputElement input = findElements('input')[0] as InputElement;
+    final web.HTMLInputElement input = findElements('input').item(0)! as web.HTMLInputElement;
     dispatchKeyboardEvent(input, 'keydown', <String, dynamic>{
       'keyCode': 13, // Enter.
       'cancelable': true,
@@ -111,9 +111,9 @@ void main() {
     await tester.tap(find.byKey(const Key('input')));
 
     // A native input element will be appended to the DOM.
-    final List<Node> nodeList = findElements('input');
+    final web.NodeList nodeList = findElements('input');
     expect(nodeList.length, equals(1));
-    final InputElement input = nodeList[0] as InputElement;
+    final web.HTMLInputElement input = nodeList.item(0)! as web.HTMLInputElement;
 
     // Press Tab. The focus should move to the next TextFormField.
     dispatchKeyboardEvent(input, 'keydown', <String, dynamic>{
@@ -136,7 +136,7 @@ void main() {
 
     // A native input element for the next TextField should be attached to the
     // DOM.
-    final InputElement input2 = findElements('input')[0] as InputElement;
+    final web.HTMLInputElement input2 = findElements('input').item(0)! as web.HTMLInputElement;
     expect(input2.value, 'Text2');
   }, semanticsEnabled: false);
 
@@ -150,9 +150,9 @@ void main() {
     await tester.tap(find.byKey(const Key('input')));
 
     // A native input element will be appended to the DOM.
-    final List<Node> nodeList = findElements('input');
+    final web.NodeList nodeList = findElements('input');
     expect(nodeList.length, equals(1));
-    final InputElement input = nodeList[0] as InputElement;
+    final web.HTMLInputElement input = nodeList.item(0)! as web.HTMLInputElement;
 
     // Press and release CapsLock.
     dispatchKeyboardEvent(input, 'keydown', <String, dynamic>{
@@ -191,7 +191,7 @@ void main() {
 
     // A native input element for the next TextField should be attached to the
     // DOM.
-    final InputElement input2 = findElements('input')[0] as InputElement;
+    final web.HTMLInputElement input2 = findElements('input').item(0)! as web.HTMLInputElement;
     expect(input2.value, 'Text2');
   }, semanticsEnabled: false);
 
@@ -215,16 +215,16 @@ void main() {
     await gesture.up();
 
     // A native input element will be appended to the DOM.
-    final List<Node> nodeList = findElements('textarea');
+    final web.NodeList nodeList = findElements('textarea');
     expect(nodeList.length, equals(1));
-    final TextAreaElement input = nodeList[0] as TextAreaElement;
+    final web.HTMLTextAreaElement input = nodeList.item(0)! as web.HTMLTextAreaElement;
     // The element's value should contain the selectable text.
     expect(input.value, text);
     expect(input.hasAttribute('readonly'), isTrue);
 
     // Make sure the entire text is selected.
     TextRange? range =
-        TextRange(start: input.selectionStart!, end: input.selectionEnd!);
+        TextRange(start: input.selectionStart, end: input.selectionEnd);
     expect(range.textInside(text), text);
 
     // Double tap to select the first word.
@@ -236,7 +236,7 @@ void main() {
     await gesture.up();
     await gesture.down(firstWordOffset);
     await gesture.up();
-    range = TextRange(start: input.selectionStart!, end: input.selectionEnd!);
+    range = TextRange(start: input.selectionStart, end: input.selectionEnd);
     expect(range.textInside(text), 'Lorem');
 
     // Double tap to select the last word.
@@ -248,21 +248,21 @@ void main() {
     await gesture.up();
     await gesture.down(lastWordOffset);
     await gesture.up();
-    range = TextRange(start: input.selectionStart!, end: input.selectionEnd!);
+    range = TextRange(start: input.selectionStart, end: input.selectionEnd);
     expect(range.textInside(text), 'amet');
   }, semanticsEnabled: false);
 }
 
-KeyboardEvent dispatchKeyboardEvent(
-    EventTarget target, String type, Map<String, dynamic> args) {
-  final Object jsKeyboardEvent = js_util.getProperty(window, 'KeyboardEvent') as Object;
+web.KeyboardEvent dispatchKeyboardEvent(
+    web.EventTarget target, String type, Map<String, dynamic> args) {
+  final Object jsKeyboardEvent = js_util.getProperty(web.window, 'KeyboardEvent') as Object;
   final List<dynamic> eventArgs = <dynamic>[
     type,
     args,
   ];
-  final KeyboardEvent event = js_util.callConstructor(
+  final web.KeyboardEvent event = js_util.callConstructor(
           jsKeyboardEvent, js_util.jsify(eventArgs) as List<dynamic>)
-      as KeyboardEvent;
+      as web.KeyboardEvent;
   target.dispatchEvent(event);
 
   return event;

dev/integration_tests/web_e2e_tests/test_driver/url_strategy_integration.dart

@@ -3,13 +3,16 @@
 // found in the LICENSE file.
 
 import 'dart:async';
-import 'dart:html' as html;
+import 'dart:js_interop';
 import 'dart:ui' as ui;
+import 'dart:ui_web';
 
 import 'package:flutter/material.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:flutter_web_plugins/flutter_web_plugins.dart';
 import 'package:integration_test/integration_test.dart';
+import 'package:web/helpers.dart';
+import 'package:web/web.dart' as web;
 import 'package:web_e2e_tests/url_strategy_main.dart' as app;
 
 void main() {
@@ -56,7 +59,7 @@ class TestUrlStrategy extends UrlStrategy {
   String getPath() => currentEntry.url;
 
   @override
-  dynamic getState() => currentEntry.state;
+  Object? getState() => currentEntry.state;
 
   int _currentEntryIndex;
   final List<TestHistoryEntry> history;
@@ -111,10 +114,10 @@ class TestUrlStrategy extends UrlStrategy {
     });
   }
 
-  final List<html.EventListener> listeners = <html.EventListener>[];
+  final List<PopStateListener> listeners = <PopStateListener>[];
 
   @override
-  ui.VoidCallback addPopStateListener(html.EventListener fn) {
+  ui.VoidCallback addPopStateListener(PopStateListener fn) {
     listeners.add(fn);
     return () {
       // Schedule a micro task here to avoid removing the listener during
@@ -134,9 +137,9 @@ class TestUrlStrategy extends UrlStrategy {
   /// like a real browser.
   void _firePopStateEvent() {
     assert(withinAppHistory);
-    final html.PopStateEvent event = html.PopStateEvent(
+    final web.PopStateEvent event = web.PopStateEvent(
       'popstate',
-      <String, dynamic>{'state': currentEntry.state},
+      PopStateEventInit(state: currentEntry.state?.toJSBox),
     );
     for (int i = 0; i < listeners.length; i++) {
       listeners[i](event);
@@ -160,7 +163,7 @@ class TestUrlStrategy extends UrlStrategy {
 class TestHistoryEntry {
   const TestHistoryEntry(this.state, this.title, this.url);
 
-  final dynamic state;
+  final Object? state;
   final String? title;
   final String url;
 

examples/api/test/flutter_test_config.dart

@@ -5,7 +5,7 @@
 import 'dart:async';
 
 
-import 'goldens_io.dart' if (dart.library.html) 'goldens_web.dart' as flutter_goldens;
+import 'goldens_io.dart' if (dart.library.js_interop) 'goldens_web.dart' as flutter_goldens;
 
 Future<void> testExecutable(FutureOr<void> Function() testMain) {
   // Enable golden file testing using Skia Gold.

packages/flutter/lib/src/foundation/_bitfield_web.dart

@@ -4,7 +4,7 @@
 
 import 'bitfield.dart' as bitfield;
 
-/// The dart:html implementation of [bitfield.kMaxUnsignedSMI].
+/// The web implementation of [bitfield.kMaxUnsignedSMI].
 ///
 /// This value is used as an optimization to coerce some numbers to be within
 /// the SMI range and avoid heap allocations. Because number encoding is
@@ -13,14 +13,14 @@ import 'bitfield.dart' as bitfield;
 /// does not have to guarantee efficiency.
 const int kMaxUnsignedSMI = -1;
 
-/// The dart:html implementation of [bitfield.Bitfield].
+/// The web implementation of [bitfield.Bitfield].
 class BitField<T extends dynamic> implements bitfield.BitField<T> {
-  /// The dart:html implementation of [bitfield.Bitfield].
+  /// The web implementation of [bitfield.Bitfield].
   // Can remove when we have metaclasses.
   // ignore: avoid_unused_constructor_parameters
   BitField(int length);
 
-  /// The dart:html implementation of [bitfield.Bitfield.filled].
+  /// The web implementation of [bitfield.Bitfield.filled].
   // Can remove when we have metaclasses.
   // ignore: avoid_unused_constructor_parameters
   BitField.filled(int length, bool value);

packages/flutter/lib/src/foundation/_isolates_web.dart

@@ -6,7 +6,7 @@ import 'isolates.dart' as isolates;
 
 export 'isolates.dart' show ComputeCallback;
 
-/// The dart:html implementation of [isolate.compute].
+/// The web implementation of [isolate.compute].
 @pragma('dart2js:tryInline')
 Future<R> compute<M, R>(isolates.ComputeCallback<M, R> callback, M message, { String? debugLabel }) async {
   // To avoid blocking the UI immediately for an expensive function call, we

packages/flutter/test/flutter_test_config.dart

@@ -10,7 +10,7 @@ import 'package:flutter/rendering.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:leak_tracker_flutter_testing/leak_tracker_flutter_testing.dart';
 
-import '_goldens_io.dart' if (dart.library.html) '_goldens_web.dart'
+import '_goldens_io.dart' if (dart.library.js_interop) '_goldens_web.dart'
     as flutter_goldens;
 
 /// If true, leak tracking is enabled for all `testWidgets`.

packages/flutter_driver/lib/src/extension/_extension_io.dart

@@ -6,7 +6,7 @@
 ///
 /// See also:
 ///
-///  * [_extension_web.dart], which has the dart:html implementation
+///  * [_extension_web.dart], which has the web implementation
 void registerWebServiceExtension(Future<Map<String, dynamic>> Function(Map<String, String>) call) {
   throw UnsupportedError('Use registerServiceExtension instead');
 }

packages/flutter_driver/lib/src/extension/_extension_web.dart

@@ -3,11 +3,13 @@
 // found in the LICENSE file.
 
 import 'dart:convert';
-import 'dart:html' as html;
-import 'dart:js';
-import 'dart:js_util' as js_util;
+import 'dart:js_interop';
+import 'dart:js_interop_unsafe';
 
-/// The dart:html implementation of [registerWebServiceExtension].
+@JS('window')
+external JSObject get _window;
+
+/// The web implementation of [registerWebServiceExtension].
 ///
 /// Registers Web Service Extension for Flutter Web application.
 ///
@@ -21,13 +23,13 @@ void registerWebServiceExtension(Future<Map<String, dynamic>> Function(Map<Strin
   // Define the result variable because packages/flutter_driver/lib/src/driver/web_driver.dart
   // checks for this value to become non-null when waiting for the result. If this value is
   // undefined at the time of the check, WebDriver throws an exception.
-  context[r'$flutterDriverResult'] = null;
+  _window.setProperty(r'$flutterDriverResult'.toJS, null);
 
-  js_util.setProperty(html.window, r'$flutterDriver', allowInterop((dynamic message) async {
+  _window.setProperty(r'$flutterDriver'.toJS, (JSAny message) {
     final Map<String, String> params = Map<String, String>.from(
-        jsonDecode(message as String) as Map<String, dynamic>);
-    final Map<String, dynamic> result = Map<String, dynamic>.from(
-        await call(params));
-    context[r'$flutterDriverResult'] = json.encode(result);
-  }));
+        jsonDecode((message as JSString).toDart) as Map<String, dynamic>);
+    call(params).then((Map<String, dynamic> result) {
+      _window.setProperty(r'$flutterDriverResult'.toJS, json.encode(result).toJS);
+    });
+  }.toJS);
 }

packages/flutter_driver/lib/src/extension/extension.dart

@@ -20,7 +20,7 @@ import '../common/error.dart';
 import '../common/find.dart';
 import '../common/handler_factory.dart';
 import '../common/message.dart';
-import '_extension_io.dart' if (dart.library.html) '_extension_web.dart';
+import '_extension_io.dart' if (dart.library.js_interop) '_extension_web.dart';
 
 const String _extensionMethodName = 'driver';
 

packages/flutter_driver/test/src/web_tests/web_extension_test.dart

@@ -2,11 +2,15 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:js' as js;
+import 'dart:js_interop';
+import 'dart:js_interop_unsafe';
 
 import 'package:flutter_driver/src/extension/_extension_web.dart';
 import 'package:flutter_test/flutter_test.dart';
 
+@JS('window')
+external JSObject get _window;
+
 void main() {
   group('test web_extension', () {
     late Future<Map<String, dynamic>> Function(Map<String, String>) call;
@@ -21,11 +25,11 @@ void main() {
       expect(() => registerWebServiceExtension(call),
           returnsNormally);
 
-      expect(js.context.hasProperty(r'$flutterDriver'), true);
-      expect(js.context[r'$flutterDriver'], isNotNull);
+      expect(_window.hasProperty(r'$flutterDriver'.toJS).toDart, true);
+      expect(_window.getProperty(r'$flutterDriver'.toJS), isNotNull);
 
-      expect(js.context.hasProperty(r'$flutterDriverResult'), true);
-      expect(js.context[r'$flutterDriverResult'], isNull);
+      expect(_window.hasProperty(r'$flutterDriverResult'.toJS).toDart, true);
+      expect(_window.getProperty(r'$flutterDriverResult'.toJS), isNull);
     });
   });
 }

packages/flutter_test/lib/flutter_test.dart

@@ -55,8 +55,9 @@ library flutter_test;
 
 export 'dart:async' show Future;
 
-export 'src/_goldens_io.dart' if (dart.library.html) 'src/_goldens_web.dart';
-export 'src/_matchers_io.dart' if (dart.library.html) 'src/_matchers_web.dart';
+export 'src/_goldens_io.dart' if (dart.library.js_interop) 'src/_goldens_web.dart';
+export 'src/_matchers_io.dart' if (dart.library.js_interop) 'src/_matchers_web.dart';
+export 'src/_test_selector_io.dart' if (dart.library.js_interop) 'src/_test_selector_web.dart';
 export 'src/accessibility.dart';
 export 'src/animation_sheet.dart';
 export 'src/binding.dart';

packages/flutter_test/lib/src/_goldens_io.dart

@@ -292,6 +292,11 @@ ByteData _invert(ByteData imageBytes) {
 
 /// An unsupported [WebGoldenComparator] that exists for API compatibility.
 class DefaultWebGoldenComparator extends WebGoldenComparator {
+  /// This is provided to prevent warnings from the analyzer.
+  DefaultWebGoldenComparator(Uri _) {
+    throw UnsupportedError('DefaultWebGoldenComparator is only supported on the web.');
+  }
+
   @override
   Future<bool> compare(double width, double height, Uri golden) {
     throw UnsupportedError('DefaultWebGoldenComparator is only supported on the web.');

packages/flutter_test/lib/src/_goldens_web.dart

@@ -3,12 +3,13 @@
 // found in the LICENSE file.
 
 import 'dart:convert';
-import 'dart:html' as html;
+import 'dart:js_interop';
 import 'dart:typed_data';
 
 import 'package:matcher/expect.dart' show fail;
 
 import 'goldens.dart';
+import 'web.dart' as web;
 
 /// An unsupported [GoldenFileComparator] that exists for API compatibility.
 class LocalFileComparator extends GoldenFileComparator {
@@ -58,21 +59,23 @@ class DefaultWebGoldenComparator extends WebGoldenComparator {
   @override
   Future<bool> compare(double width, double height, Uri golden) async {
     final String key = golden.toString();
-    final html.HttpRequest request = await html.HttpRequest.request(
-      'flutter_goldens',
-      method: 'POST',
-      sendData: json.encode(<String, Object>{
-        'testUri': testUri.toString(),
-        'key': key,
-        'width': width.round(),
-        'height': height.round(),
-      }),
-    );
-    final String response = request.response as String;
-    if (response == 'true') {
+    final web.Response response = await web.window.fetch(
+      'flutter_goldens'.toJS,
+      web.RequestInit(
+        method: 'POST',
+        body: json.encode(<String, Object>{
+          'testUri': testUri.toString(),
+          'key': key,
+          'width': width.round(),
+          'height': height.round(),
+        }).toJS,
+      )
+    ).toDart;
+    final String responseText = (await response.text().toDart).toDart;
+    if (responseText == 'true') {
       return true;
     }
-    fail(response);
+    fail(responseText);
   }
 
   @override
@@ -85,20 +88,22 @@ class DefaultWebGoldenComparator extends WebGoldenComparator {
   Future<bool> compareBytes(Uint8List bytes, Uri golden) async {
     final String key = golden.toString();
     final String bytesEncoded = base64.encode(bytes);
-    final html.HttpRequest request = await html.HttpRequest.request(
-      'flutter_goldens',
-      method: 'POST',
-      sendData: json.encode(<String, Object>{
-        'testUri': testUri.toString(),
-        'key': key,
-        'bytes': bytesEncoded,
-      }),
-    );
-    final String response = request.response as String;
-    if (response == 'true') {
+    final web.Response response = await web.window.fetch(
+      'flutter_goldens'.toJS,
+      web.RequestInit(
+        method: 'POST',
+        body: json.encode(<String, Object>{
+          'testUri': testUri.toString(),
+          'key': key,
+          'bytes': bytesEncoded,
+        }).toJS,
+      )
+    ).toDart;
+    final String responseText = (await response.text().toDart).toDart;
+    if (responseText == 'true') {
       return true;
     }
-    fail(response);
+    fail(responseText);
   }
 
   @override

packages/flutter_test/lib/src/_test_selector_io.dart

+// Copyright 2014 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// This is an empty file that is imported instead of web_test_selector.dart on
+// non-web platforms.

packages/flutter_test/lib/src/_test_selector_web.dart

+// Copyright 2014 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'dart:async';
+import 'dart:js_interop';
+import 'dart:ui' as ui;
+import 'dart:ui_web' as ui_web;
+
+import 'package:stream_channel/stream_channel.dart';
+import 'package:test_api/backend.dart';
+
+import '_goldens_web.dart';
+import 'goldens.dart';
+import 'web.dart' as web;
+
+// This file contains APIs that are used by the generated test harness for
+// running flutter unit tests.
+
+/// A `main` entry point for a test.
+typedef EntryPoint = FutureOr<void> Function();
+
+/// An entry point runner provided by a test config file
+typedef EntryPointRunner = Future<void> Function(EntryPoint);
+
+/// Metadata about a web test to run
+typedef WebTest = ({
+  EntryPoint entryPoint,
+  EntryPointRunner? entryPointRunner,
+  Uri goldensUri,
+});
+
+/// Gets the test selector set by the test bootstrapping logic
+String get testSelector {
+  final JSString? jsTestSelector = web.window.testSelector;
+  if (jsTestSelector == null) {
+    throw Exception('Test selector not set');
+  }
+  return  jsTestSelector.toDart;
+}
+
+/// Runs a specific web test
+Future<void> runWebTest(WebTest test) async {
+  ui_web.debugEmulateFlutterTesterEnvironment = true;
+  final Completer<void> completer = Completer<void>();
+  await ui_web.bootstrapEngine(runApp: () => completer.complete());
+  await completer.future;
+  webGoldenComparator = DefaultWebGoldenComparator(test.goldensUri);
+
+  /// This hard-codes the device pixel ratio to 3.0 and a 2400 x 1800 window
+  /// size for the purposes of testing.
+  ui_web.debugOverrideDevicePixelRatio(3.0);
+  ui.window.debugPhysicalSizeOverride = const ui.Size(2400, 1800);
+
+  final EntryPointRunner? entryPointRunner = test.entryPointRunner;
+  final EntryPoint entryPoint = test.entryPoint;
+  _internalBootstrapBrowserTest(() {
+    return entryPointRunner != null ? () => entryPointRunner(entryPoint) : entryPoint;
+  });
+}
+
+void _internalBootstrapBrowserTest(EntryPoint Function() getMain) {
+  final StreamChannel<Object?> channel = _serializeSuite(getMain, hidePrints: false);
+  _postMessageChannel().pipe(channel);
+}
+
+StreamChannel<Object?> _serializeSuite(EntryPoint Function() getMain, {bool hidePrints = true}) => RemoteListener.start(getMain, hidePrints: hidePrints);
+
+StreamChannel<Object?> _postMessageChannel() {
+  final StreamChannelController<Object?> controller = StreamChannelController<Object?>(sync: true);
+  final web.MessageChannel channel = web.MessageChannel();
+  web.window.parent!.postMessage('port'.toJS, web.window.location.origin, <JSObject>[channel.port2].toJS);
+
+  final JSFunction eventCallback = (web.Event event) {
+    controller.local.sink.add(event.data.dartify());
+  }.toJS;
+  channel.port1.addEventListener('message'.toJS, eventCallback);
+  channel.port1.start();
+  controller.local.stream.listen(
+    (Object? message) => channel.port1.postMessage(message.jsify()),
+    onDone: () => channel.port1.removeEventListener('message'.toJS, eventCallback),
+  );
+
+  return controller.foreign;
+}

packages/flutter_test/lib/src/binding.dart

@@ -18,7 +18,7 @@ import 'package:stack_trace/stack_trace.dart' as stack_trace;
 import 'package:test_api/scaffolding.dart' as test_package show Timeout;
 import 'package:vector_math/vector_math_64.dart';
 
-import '_binding_io.dart' if (dart.library.html) '_binding_web.dart' as binding;
+import '_binding_io.dart' if (dart.library.js_interop) '_binding_web.dart' as binding;
 import 'goldens.dart';
 import 'platform.dart';
 import 'restoration.dart';

packages/flutter_test/lib/src/goldens.dart

@@ -8,7 +8,7 @@ import 'dart:ui';
 import 'package:meta/meta.dart';
 import 'package:path/path.dart' as path;
 
-import '_goldens_io.dart' if (dart.library.html) '_goldens_web.dart' as goldens;
+import '_goldens_io.dart' if (dart.library.js_interop) '_goldens_web.dart' as goldens;
 
 /// Compares image pixels against a golden image file.
 ///

packages/flutter_test/lib/src/matchers.dart

@@ -14,7 +14,7 @@ import 'package:matcher/expect.dart';
 import 'package:matcher/src/expect/async_matcher.dart'; // ignore: implementation_imports
 import 'package:vector_math/vector_math_64.dart' show Matrix3;
 
-import '_matchers_io.dart' if (dart.library.html) '_matchers_web.dart' show MatchesGoldenFile, captureImage;
+import '_matchers_io.dart' if (dart.library.js_interop) '_matchers_web.dart' show MatchesGoldenFile, captureImage;
 import 'accessibility.dart';
 import 'binding.dart';
 import 'controller.dart';

packages/flutter_test/lib/src/web.dart

+// Copyright 2014 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// This code is copied from `package:web` which still needs its own
+// documentation for public members. Since this is a shim that users should not
+// use, we ignore this lint for this file.
+// ignore_for_file: public_member_api_docs
+
+/// A stripped down version of `package:web` to avoid pinning that repo in
+/// Flutter as a dependency.
+///
+/// These are manually copied over from `package:web` as needed, and should stay
+/// in sync with the latest package version as much as possible.
+///
+/// If missing members are needed, copy them over into the corresponding
+/// extension or interface. If missing interfaces/types are needed, copy them
+/// over while excluding unnecessary inheritance to make the copy minimal. These
+/// types are erased at runtime, so excluding supertypes is safe. If a member is
+/// needed that belongs to a supertype, then add the necessary `implements`
+/// clause to the subtype when you add that supertype. Keep extensions next to
+/// the interface they extend.
+library;
+
+import 'dart:js_interop';
+
+@JS()
+external Window get window;
+
+extension type Window._(JSObject _) implements JSObject {
+  external JSPromise<Response> fetch(
+    JSAny input, [
+    RequestInit init,
+  ]);
+  external Location get location;
+  external Window? get parent;
+  external void postMessage(JSAny message, JSString targetOrigin, JSArray<JSAny> transfers);
+
+  external JSString? get testSelector;
+}
+
+extension type Response._(JSObject _) implements JSObject {
+  external JSPromise<JSString> text();
+}
+
+extension type RequestInit._(JSObject _) implements JSObject {
+  external factory RequestInit({
+    String method,
+    JSAny? body,
+  });
+}
+
+extension type Location._(JSObject _) implements JSObject {
+  external JSString get origin;
+}
+
+extension type MessageChannel._(JSObject _) implements JSObject {
+  external factory MessageChannel();
+
+  external MessagePort port1;
+  external MessagePort port2;
+}
+
+extension type MessagePort._(JSObject _) implements JSObject {
+  external void addEventListener(JSString eventName, JSFunction callback);
+  external void removeEventListener(JSString eventName, JSFunction callback);
+  external void postMessage(JSAny? message);
+
+  external void start();
+}
+
+extension type Event._(JSObject _) implements JSObject {
+  external JSObject? get data;
+}

packages/flutter_test/pubspec.yaml

 name: flutter_test
 
 environment:
-  sdk: '>=3.2.0-0 <4.0.0'
+  sdk: '>=3.3.0-0 <4.0.0'
 
 dependencies:
   # To update these, use "flutter update-packages --force-upgrade".

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

@@ -12,6 +12,7 @@ import '../build_info.dart';
 import '../bundle_builder.dart';
 import '../devfs.dart';
 import '../device.dart';
+import '../features.dart';
 import '../globals.dart' as globals;
 import '../native_assets.dart';
 import '../project.dart';
@@ -23,6 +24,7 @@ import '../test/test_time_recorder.dart';
 import '../test/test_wrapper.dart';
 import '../test/watcher.dart';
 import '../web/compile.dart';
+import '../web/web_constants.dart';
 
 /// The name of the directory where Integration Tests are placed.
 ///
@@ -233,7 +235,14 @@ class TestCommand extends FlutterCommand with DeviceBasedDevelopmentArtifacts {
               'in seconds (e.g. "60s"), '
               'as a multiplier of the default timeout (e.g. "2x"), '
               'or as the string "none" to disable the timeout entirely.',
+      )
+      ..addFlag(
+        FlutterOptions.kWebWasmFlag,
+        help: 'Compile to WebAssembly rather than JavaScript.\n$kWasmMoreInfo',
+        negatable: false,
+        hide: !featureFlags.isFlutterWebWasmEnabled,
       );
+
     addDdsOptions(verboseHelp: verboseHelp);
     addServeObservatoryOptions(verboseHelp: verboseHelp);
     usesFatalWarningsOption(verboseHelp: verboseHelp);
@@ -256,6 +265,7 @@ class TestCommand extends FlutterCommand with DeviceBasedDevelopmentArtifacts {
   final Set<Uri> _testFileUris = <Uri>{};
 
   bool get isWeb => stringArg('platform') == 'chrome';
+  bool get useWasm => boolArg(FlutterOptions.kWebWasmFlag);
 
   @override
   Future<Set<DevelopmentArtifact>> get requiredArtifacts async {
@@ -499,6 +509,10 @@ class TestCommand extends FlutterCommand with DeviceBasedDevelopmentArtifacts {
       watcher = collector;
     }
 
+    if (!isWeb && useWasm) {
+      throwToolExit('--wasm is only supported on the web platform');
+    }
+
     Device? integrationTestDevice;
     if (_isIntegrationTest) {
       integrationTestDevice = await findTargetDevice();
@@ -577,6 +591,7 @@ class TestCommand extends FlutterCommand with DeviceBasedDevelopmentArtifacts {
         testAssetDirectory: testAssetDirectory,
         flutterProject: flutterProject,
         web: isWeb,
+        useWasm: useWasm,
         randomSeed: stringArg('test-randomize-ordering-seed'),
         reporter: stringArg('reporter'),
         fileReporter: stringArg('file-reporter'),

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

@@ -37,7 +37,7 @@ import 'flutter_web_goldens.dart';
 import 'test_compiler.dart';
 import 'test_time_recorder.dart';
 
-shelf.Handler createDirectoryHandler(Directory directory) {
+shelf.Handler createDirectoryHandler(Directory directory, { required bool crossOriginIsolated} ) {
   final mime.MimeTypeResolver resolver = mime.MimeTypeResolver();
   final FileSystem fileSystem = directory.fileSystem;
   return (shelf.Request request) async {
@@ -56,10 +56,16 @@ shelf.Handler createDirectoryHandler(Directory directory) {
       return shelf.Response.notFound('Not Found');
     }
     final String? contentType = resolver.lookup(file.path);
+    final bool needsCrossOriginIsolated = crossOriginIsolated && uriPath.endsWith('.html');
     return shelf.Response.ok(
       file.openRead(),
       headers: <String, String>{
-        if (contentType != null) 'Content-Type': contentType
+        if (contentType != null) 'Content-Type': contentType,
+        if (needsCrossOriginIsolated)
+          ...<String, String>{
+            'Cross-Origin-Opener-Policy': 'same-origin',
+            'Cross-Origin-Embedder-Policy': 'require-corp',
+          },
       },
     );
   };
@@ -74,6 +80,7 @@ class FlutterWebPlatform extends PlatformPlugin {
     required this.buildInfo,
     required this.webMemoryFS,
     required FileSystem fileSystem,
+    required Directory buildDirectory,
     required File testDartJs,
     required File testHostDartJs,
     required ChromiumLauncher chromiumLauncher,
@@ -81,8 +88,10 @@ class FlutterWebPlatform extends PlatformPlugin {
     required Artifacts? artifacts,
     required ProcessManager processManager,
     required this.webRenderer,
+    required this.useWasm,
     TestTimeRecorder? testTimeRecorder,
   }) : _fileSystem = fileSystem,
+      _buildDirectory = buildDirectory,
       _testDartJs = testDartJs,
       _testHostDartJs = testHostDartJs,
       _chromiumLauncher = chromiumLauncher,
@@ -92,6 +101,7 @@ class FlutterWebPlatform extends PlatformPlugin {
         .add(_webSocketHandler.handler)
         .add(createDirectoryHandler(
           fileSystem.directory(fileSystem.path.join(Cache.flutterRoot!, 'packages', 'flutter_tools')),
+          crossOriginIsolated: webRenderer == WebRendererMode.skwasm,
         ))
         .add(_handleStaticArtifact)
         .add(_localCanvasKitHandler)
@@ -99,7 +109,8 @@ class FlutterWebPlatform extends PlatformPlugin {
         .add(_wrapperHandler)
         .add(_handleTestRequest)
         .add(createDirectoryHandler(
-          fileSystem.directory(fileSystem.path.join(fileSystem.currentDirectory.path, 'test'))
+          fileSystem.directory(fileSystem.path.join(fileSystem.currentDirectory.path, 'test')),
+          crossOriginIsolated: webRenderer == WebRendererMode.skwasm,
         ))
         .add(_packageFilesHandler);
     _server.mount(cascade.handler);
@@ -116,6 +127,7 @@ class FlutterWebPlatform extends PlatformPlugin {
   final WebMemoryFS webMemoryFS;
   final BuildInfo buildInfo;
   final FileSystem _fileSystem;
+  final Directory _buildDirectory;
   final File _testDartJs;
   final File _testHostDartJs;
   final ChromiumLauncher _chromiumLauncher;
@@ -127,6 +139,7 @@ class FlutterWebPlatform extends PlatformPlugin {
   final AsyncMemoizer<void> _closeMemo = AsyncMemoizer<void>();
   final String _root;
   final WebRendererMode webRenderer;
+  final bool useWasm;
 
   /// Allows only one test suite (typically one test file) to be loaded and run
   /// at any given point in time. Loading more than one file at a time is known
@@ -149,11 +162,13 @@ class FlutterWebPlatform extends PlatformPlugin {
     required BuildInfo buildInfo,
     required WebMemoryFS webMemoryFS,
     required FileSystem fileSystem,
+    required Directory buildDirectory,
     required Logger logger,
     required ChromiumLauncher chromiumLauncher,
     required Artifacts? artifacts,
     required ProcessManager processManager,
     required WebRendererMode webRenderer,
+    required bool useWasm,
     TestTimeRecorder? testTimeRecorder,
     Uri? testPackageUri,
     Future<shelf.Server> Function() serverFactory = defaultServerFactory,
@@ -196,12 +211,14 @@ class FlutterWebPlatform extends PlatformPlugin {
       testDartJs: testDartJs,
       testHostDartJs: testHostDartJs,
       fileSystem: fileSystem,
+      buildDirectory: buildDirectory,
       chromiumLauncher: chromiumLauncher,
       artifacts: artifacts,
       logger: logger,
       nullAssertions: nullAssertions,
       processManager: processManager,
       webRenderer: webRenderer,
+      useWasm: useWasm,
       testTimeRecorder: testTimeRecorder,
     );
   }
@@ -254,6 +271,11 @@ class FlutterWebPlatform extends PlatformPlugin {
     'dart_stack_trace_mapper.js',
   ));
 
+  File get _flutterJs => _fileSystem.file(_fileSystem.path.join(
+    _artifacts!.getHostArtifact(HostArtifact.flutterJsDirectory).path,
+    'flutter.js',
+  ));
+
   File get _dartSdk {
     final Map<WebRendererMode, Map<NullSafetyMode, HostArtifact>> dartSdkArtifactMap = buildInfo.ddcModuleFormat == DdcModuleFormat.ddc ? kDdcDartSdkJsArtifactMap : kAmdDartSdkJsArtifactMap;
     return _fileSystem.file(_artifacts!.getHostArtifact(dartSdkArtifactMap[webRenderer]![_nullSafetyMode]!));
@@ -277,21 +299,20 @@ class FlutterWebPlatform extends PlatformPlugin {
   }
 
   Future<shelf.Response> _handleTestRequest(shelf.Request request) async {
-    if (request.url.path.endsWith('.dart.browser_test.dart.js')) {
-      final String leadingPath = request.url.path.split('.browser_test.dart.js')[0];
-      final String generatedFile = '${_fileSystem.path.split(leadingPath).join('_')}.bootstrap.js';
-      return shelf.Response.ok(generateTestBootstrapFileContents('/$generatedFile', 'require.js', 'dart_stack_trace_mapper.js'), headers: <String, String>{
-        HttpHeaders.contentTypeHeader: 'text/javascript',
-      });
+    if (request.url.path.endsWith('main.dart.browser_test.dart.js')) {
+      return shelf.Response.ok(generateTestBootstrapFileContents(
+        '/main.dart.bootstrap.js', 'require.js', 'dart_stack_trace_mapper.js'),
+        headers: <String, String>{
+          HttpHeaders.contentTypeHeader: 'text/javascript',
+        }
+      );
     }
-    if (request.url.path.endsWith('.dart.bootstrap.js')) {
-      final String leadingPath = request.url.path.split('.dart.bootstrap.js')[0];
-      final String generatedFile = '${_fileSystem.path.split(leadingPath).join('_')}.dart.test.dart.js';
+    if (request.url.path.endsWith('main.dart.bootstrap.js')) {
       return shelf.Response.ok(generateMainModule(
         nullAssertions: nullAssertions!,
         nativeNullAssertions: true,
-        bootstrapModule: '${_fileSystem.path.basename(leadingPath)}.dart.bootstrap',
-        entrypoint: '/$generatedFile'
+        bootstrapModule: 'main.dart.bootstrap',
+        entrypoint: '/main.dart.js'
        ), headers: <String, String>{
         HttpHeaders.contentTypeHeader: 'text/javascript',
       });
@@ -349,6 +370,21 @@ class FlutterWebPlatform extends PlatformPlugin {
         _testHostDartJs.openRead(),
         headers: <String, String>{'Content-Type': 'text/javascript'},
       );
+    } else if (request.requestedUri.path.contains('flutter.js')) {
+      return shelf.Response.ok(
+        _flutterJs.openRead(),
+        headers: <String, String>{'Content-Type': 'text/javascript'},
+      );
+    } else if (request.requestedUri.path.contains('main.dart.mjs')) {
+      return shelf.Response.ok(
+        _buildDirectory.childFile('main.dart.mjs').openRead(),
+        headers: <String, String>{'Content-Type': 'text/javascript'},
+      );
+    } else if (request.requestedUri.path.contains('main.dart.wasm')) {
+      return shelf.Response.ok(
+        _buildDirectory.childFile('main.dart.wasm').openRead(),
+        headers: <String, String>{'Content-Type': 'application/wasm'},
+      );
     } else {
       return shelf.Response.notFound('Not Found');
     }
@@ -363,7 +399,10 @@ class FlutterWebPlatform extends PlatformPlugin {
       if (fileUri != null) {
         final String dirname = _fileSystem.path.dirname(fileUri.toFilePath());
         final String basename = _fileSystem.path.basename(fileUri.toFilePath());
-        final shelf.Handler handler = createDirectoryHandler(_fileSystem.directory(dirname));
+        final shelf.Handler handler = createDirectoryHandler(
+          _fileSystem.directory(dirname),
+          crossOriginIsolated: webRenderer == WebRendererMode.skwasm,
+        );
         final shelf.Request modifiedRequest = shelf.Request(
           request.method,
           request.requestedUri.replace(path: basename),
@@ -452,36 +491,66 @@ class FlutterWebPlatform extends PlatformPlugin {
         return shelf.Response.internalServerError(body: error);
     }
 
+    final File canvasKitFile = _canvasKitFile(relativePath);
     return shelf.Response.ok(
-      _canvasKitFile(relativePath).openRead(),
+      canvasKitFile.openRead(),
       headers: <String, Object>{
         HttpHeaders.contentTypeHeader: contentType,
       },
     );
   }
 
+  String _makeBuildConfigString() {
+    return useWasm ? '''
+      {
+        compileTarget: "dart2wasm",
+        renderer: "${webRenderer.name}",
+        mainWasmPath: "main.dart.wasm",
+        jsSupportRuntimePath: "main.dart.mjs",
+      }
+''' : '''
+      {
+        compileTarget: "dartdevc",
+        renderer: "${webRenderer.name}",
+        mainJsPath: "main.dart.browser_test.dart.js",
+      }
+''';
+  }
+
   // A handler that serves wrapper files used to bootstrap tests.
   shelf.Response _wrapperHandler(shelf.Request request) {
     final String path = _fileSystem.path.fromUri(request.url);
     if (path.endsWith('.html')) {
       final String test = '${_fileSystem.path.withoutExtension(path)}.dart';
-      final String scriptBase = htmlEscape.convert(_fileSystem.path.basename(test));
-      final String link = '<link rel="x-dart-test" href="$scriptBase">';
       return shelf.Response.ok('''
         <!DOCTYPE html>
         <html>
         <head>
           <title>${htmlEscape.convert(test)} Test</title>
+          <script src="flutter.js"></script>
           <script>
-            window.flutterConfiguration = {
-              canvasKitBaseUrl: "/canvaskit/"
-            };
+            _flutter.buildConfig = {
+              builds: [
+                ${_makeBuildConfigString()}
+              ]
+            }
+            window.testSelector = "$test";
+            _flutter.loader.load({
+              config: {
+                canvasKitBaseUrl: "/canvaskit/",
+              }
+            });
           </script>
-          $link
-          <script src="static/dart.js"></script>
         </head>
         </html>
-      ''', headers: <String, String>{'Content-Type': 'text/html'});
+      ''', headers: <String, String>{
+        'Content-Type': 'text/html',
+        if (webRenderer == WebRendererMode.skwasm)
+          ...<String, String>{
+            'Cross-Origin-Opener-Policy': 'same-origin',
+            'Cross-Origin-Embedder-Policy': 'require-corp',
+          }
+      });
     }
     return shelf.Response.notFound('Not found.');
   }

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

@@ -52,6 +52,7 @@ abstract class FlutterTestRunner {
     String? icudtlPath,
     Directory? coverageDirectory,
     bool web = false,
+    bool useWasm = false,
     String? randomSeed,
     String? reporter,
     String? fileReporter,
@@ -117,6 +118,7 @@ class _FlutterTestRunnerImpl implements FlutterTestRunner {
     String? icudtlPath,
     Directory? coverageDirectory,
     bool web = false,
+    bool useWasm = false,
     String? randomSeed,
     String? reporter,
     String? fileReporter,
@@ -186,6 +188,7 @@ class _FlutterTestRunnerImpl implements FlutterTestRunner {
         testFiles: testFiles.map((Uri uri) => uri.toFilePath()).toList(),
         buildInfo: debuggingOptions.buildInfo,
         webRenderer: debuggingOptions.webRenderer,
+        useWasm: useWasm,
       );
       testArgs
         ..add('--platform=chrome')
@@ -205,6 +208,7 @@ class _FlutterTestRunnerImpl implements FlutterTestRunner {
             webMemoryFS: result,
             logger: globals.logger,
             fileSystem: globals.fs,
+            buildDirectory: globals.fs.directory(tempBuildDir),
             artifacts: globals.artifacts,
             processManager: globals.processManager,
             chromiumLauncher: ChromiumLauncher(
@@ -217,6 +221,7 @@ class _FlutterTestRunnerImpl implements FlutterTestRunner {
             ),
             testTimeRecorder: testTimeRecorder,
             webRenderer: debuggingOptions.webRenderer,
+            useWasm: useWasm,
           );
         },
       );

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

@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 import 'package:package_config/package_config.dart';
+import 'package:package_config/package_config_types.dart';
 import 'package:process/process.dart';
 
 import '../artifacts.dart';
@@ -11,6 +12,7 @@ import '../base/config.dart';
 import '../base/file_system.dart';
 import '../base/logger.dart';
 import '../base/platform.dart';
+import '../base/process.dart';
 import '../build_info.dart';
 import '../bundle.dart';
 import '../cache.dart';
@@ -44,12 +46,74 @@ class WebTestCompiler {
   final ProcessManager _processManager;
   final Config _config;
 
+  Future<File> _generateTestEntrypoint({
+    required List<String> testFiles,
+    required Directory projectDirectory,
+    required Directory outputDirectory,
+    required LanguageVersion languageVersion,
+  }) async {
+    final List<WebTestInfo> testInfos = testFiles.map((String testFilePath) {
+      final List<String> relativeTestSegments = _fileSystem.path.split(
+        _fileSystem.path.relative(
+          testFilePath,
+          from: projectDirectory.childDirectory('test').path
+        )
+      );
+
+      final File? testConfigFile = findTestConfigFile(_fileSystem.file(testFilePath), _logger);
+      String? testConfigPath;
+      if (testConfigFile != null) {
+        testConfigPath = _fileSystem.path.split(
+          _fileSystem.path.relative(
+            testConfigFile.path,
+            from: projectDirectory.childDirectory('test').path
+          )
+        ).join('/');
+      }
+      return (
+        entryPoint: relativeTestSegments.join('/'),
+        configFile: testConfigPath,
+        goldensUri: Uri.file(testFilePath),
+      );
+    }).toList();
+    return _fileSystem.file(_fileSystem.path.join(outputDirectory.path, 'main.dart'))
+      ..createSync(recursive: true)
+      ..writeAsStringSync(generateTestEntrypoint(
+        testInfos: testInfos,
+        languageVersion: languageVersion
+      )
+    );
+  }
+
   Future<WebMemoryFS> initialize({
     required Directory projectDirectory,
     required String testOutputDir,
     required List<String> testFiles,
     required BuildInfo buildInfo,
     required WebRendererMode webRenderer,
+    required bool useWasm,
+  }) async {
+    return useWasm ? _compileWasm(
+      projectDirectory: projectDirectory,
+      testOutputDir: testOutputDir,
+      testFiles: testFiles,
+      buildInfo: buildInfo,
+      webRenderer: webRenderer,
+    ) : _compileJS(
+      projectDirectory: projectDirectory,
+      testOutputDir: testOutputDir,
+      testFiles: testFiles,
+      buildInfo: buildInfo,
+      webRenderer: webRenderer,
+    );
+  }
+
+  Future<WebMemoryFS> _compileJS({
+    required Directory projectDirectory,
+    required String testOutputDir,
+    required List<String> testFiles,
+    required BuildInfo buildInfo,
+    required WebRendererMode webRenderer,
   }) async {
     LanguageVersion languageVersion = LanguageVersion(2, 8);
     late final String platformDillName;
@@ -78,32 +142,12 @@ class WebTestCompiler {
 
     final Directory outputDirectory = _fileSystem.directory(testOutputDir)
       ..createSync(recursive: true);
-    final List<File> generatedFiles = <File>[];
-    for (final String testFilePath in testFiles) {
-      final List<String> relativeTestSegments = _fileSystem.path.split(
-        _fileSystem.path.relative(testFilePath, from: projectDirectory.childDirectory('test').path));
-      final File generatedFile = _fileSystem.file(
-        _fileSystem.path.join(outputDirectory.path, '${relativeTestSegments.join('_')}.test.dart'));
-      generatedFile
-        ..createSync(recursive: true)
-        ..writeAsStringSync(generateTestEntrypoint(
-            relativeTestPath: relativeTestSegments.join('/'),
-            absolutePath: testFilePath,
-            testConfigPath: findTestConfigFile(_fileSystem.file(testFilePath), _logger)?.path,
-            languageVersion: languageVersion,
-        ));
-      generatedFiles.add(generatedFile);
-    }
-    // Generate a fake main file that imports all tests to be executed. This will force
-    // each of them to be compiled.
-    final StringBuffer buffer = StringBuffer('// @dart=${languageVersion.major}.${languageVersion.minor}\n');
-    for (final File generatedFile in generatedFiles) {
-      buffer.writeln('import "${_fileSystem.path.basename(generatedFile.path)}";');
-    }
-    buffer.writeln('void main() {}');
-    _fileSystem.file(_fileSystem.path.join(outputDirectory.path, 'main.dart'))
-      ..createSync()
-      ..writeAsStringSync(buffer.toString());
+    final File testFile = await _generateTestEntrypoint(
+      testFiles: testFiles,
+      projectDirectory: projectDirectory,
+      outputDirectory: outputDirectory,
+      languageVersion: languageVersion
+    );
 
     final String cachedKernelPath = getDefaultCachedKernelPath(
       trackWidgetCreation: buildInfo.trackWidgetCreation,
@@ -139,7 +183,7 @@ class WebTestCompiler {
     );
 
     final CompilerOutput? output = await residentCompiler.recompile(
-      Uri.parse('org-dartlang-app:///main.dart'),
+      Uri.parse('org-dartlang-app:///${testFile.basename}'),
       <Uri>[],
       outputPath: outputDirectory.childFile('out').path,
       packageConfig: buildInfo.packageConfig,
@@ -157,7 +201,67 @@ class WebTestCompiler {
     final File manifestFile = outputDirectory.childFile('${output.outputFilename}.json');
     final File sourcemapFile = outputDirectory.childFile('${output.outputFilename}.map');
     final File metadataFile = outputDirectory.childFile('${output.outputFilename}.metadata');
+
     return WebMemoryFS()
       ..write(codeFile, manifestFile, sourcemapFile, metadataFile);
   }
+
+  Future<WebMemoryFS> _compileWasm({
+    required Directory projectDirectory,
+    required String testOutputDir,
+    required List<String> testFiles,
+    required BuildInfo buildInfo,
+    required WebRendererMode webRenderer,
+  }) async {
+    final Directory outputDirectory = _fileSystem.directory(testOutputDir)
+      ..createSync(recursive: true);
+    final File testFile = await _generateTestEntrypoint(
+      testFiles: testFiles,
+      projectDirectory: projectDirectory,
+      outputDirectory: outputDirectory,
+      languageVersion: currentLanguageVersion(_fileSystem, Cache.flutterRoot!),
+    );
+
+    final String dartSdkPath = _artifacts.getArtifactPath(Artifact.engineDartSdkPath, platform: TargetPlatform.web_javascript);
+    final String platformBinariesPath = _artifacts.getHostArtifact(HostArtifact.webPlatformKernelFolder).path;
+    final String platformFilePath = _fileSystem.path.join(platformBinariesPath, 'dart2wasm_platform.dill');
+    final List<String> dartDefines = webRenderer.updateDartDefines(buildInfo.dartDefines);
+    final File outputWasmFile = outputDirectory.childFile('main.dart.wasm');
+
+    final List<String> compilationArgs = <String>[
+      _artifacts.getArtifactPath(Artifact.engineDartBinary, platform: TargetPlatform.web_javascript),
+      'compile',
+      'wasm',
+      '--packages=.dart_tool/package_config.json',
+      '--extra-compiler-option=--dart-sdk=$dartSdkPath',
+      '--extra-compiler-option=--platform=$platformFilePath',
+      '--extra-compiler-option=--multi-root-scheme=org-dartlang-app',
+      '--extra-compiler-option=--multi-root=${projectDirectory.childDirectory('test').path}',
+      '--extra-compiler-option=--multi-root=${outputDirectory.path}',
+      if (webRenderer == WebRendererMode.skwasm) ...<String>[
+        '--extra-compiler-option=--import-shared-memory',
+        '--extra-compiler-option=--shared-memory-max-pages=32768',
+        ],
+      ...buildInfo.extraFrontEndOptions,
+      for (final String dartDefine in dartDefines)
+        '-D$dartDefine',
+
+      '-O1',
+      '-o',
+      outputWasmFile.path,
+      testFile.path, // dartfile
+    ];
+
+    final ProcessUtils processUtils = ProcessUtils(
+      logger: _logger,
+      processManager: _processManager,
+    );
+
+    await processUtils.run(
+      throwOnError: true,
+      compilationArgs,
+    );
+
+    return WebMemoryFS();
+  }
 }

packages/flutter_tools/lib/src/web/bootstrap.dart

@@ -387,59 +387,70 @@ define("$bootstrapModule", ["$entrypoint", "dart_sdk"], function(app, dart_sdk)
 ''';
 }
 
-/// Generates the bootstrap logic required for a flutter test running in a browser.
+typedef WebTestInfo = ({
+  String entryPoint,
+  Uri goldensUri,
+  String? configFile,
+});
+
+/// Generates the bootstrap logic required for running a group of unit test
+/// files in the browser.
 ///
-/// This hard-codes the device pixel ratio to 3.0 and a 2400 x 1800 window size.
+/// This creates one "switchboard" main function that imports all the main
+/// functions of the unit test files that need to be run. The javascript code
+/// that starts the test sets a `window.testSelector` that specifies which main
+/// function to invoke. This allows us to compile all the unit test files as a
+/// single web application and invoke that with a different selector for each
+/// test.
 String generateTestEntrypoint({
-  required String relativeTestPath,
-  required String absolutePath,
-  required String? testConfigPath,
+  required List<WebTestInfo> testInfos,
   required LanguageVersion languageVersion,
 }) {
-  return '''
-  // @dart = ${languageVersion.major}.${languageVersion.minor}
-  import 'org-dartlang-app:///$relativeTestPath' as test;
-  import 'dart:ui' as ui;
-  import 'dart:ui_web' as ui_web;
-  import 'dart:html';
-  import 'dart:js';
-  ${testConfigPath != null ? "import '${Uri.file(testConfigPath)}' as test_config;" : ""}
-  import 'package:stream_channel/stream_channel.dart';
-  import 'package:flutter_test/flutter_test.dart';
-  import 'package:test_api/backend.dart';
-
-  Future<void> main() async {
-    ui_web.debugEmulateFlutterTesterEnvironment = true;
-    await ui_web.bootstrapEngine();
-    webGoldenComparator = DefaultWebGoldenComparator(Uri.parse('${Uri.file(absolutePath)}'));
-    ui_web.debugOverrideDevicePixelRatio(3.0);
-    ui.window.debugPhysicalSizeOverride = const ui.Size(2400, 1800);
-
-    internalBootstrapBrowserTest(() {
-      return ${testConfigPath != null ? "() => test_config.testExecutable(test.main)" : "test.main"};
-    });
+  final List<String> importMainStatements = <String>[];
+  final List<String> importTestConfigStatements = <String>[];
+  final List<String> webTestPairs = <String>[];
+
+  for (int index = 0; index < testInfos.length; index++) {
+    final WebTestInfo testInfo = testInfos[index];
+    final String entryPointPath = testInfo.entryPoint;
+    importMainStatements.add("import 'org-dartlang-app:///${Uri.file(entryPointPath)}' as test_$index show main;");
+
+    final String? testConfigPath = testInfo.configFile;
+    String? testConfigFunction = 'null';
+    if (testConfigPath != null) {
+      importTestConfigStatements.add(
+        "import 'org-dartlang-app:///${Uri.file(testConfigPath)}' as test_config_$index show testExecutable;"
+      );
+      testConfigFunction = 'test_config_$index.testExecutable';
+    }
+    webTestPairs.add('''
+  '$entryPointPath': (
+    entryPoint: test_$index.main,
+    entryPointRunner: $testConfigFunction,
+    goldensUri: Uri.parse('${testInfo.goldensUri}'),
+  ),
+''');
   }
+  return '''
+// @dart = ${languageVersion.major}.${languageVersion.minor}
 
-  void internalBootstrapBrowserTest(Function getMain()) {
-    var channel = serializeSuite(getMain, hidePrints: false);
-    postMessageChannel().pipe(channel);
-  }
+${importMainStatements.join('\n')}
 
-  StreamChannel serializeSuite(Function getMain(), {bool hidePrints = true}) => RemoteListener.start(getMain, hidePrints: hidePrints);
+${importTestConfigStatements.join('\n')}
 
-  StreamChannel postMessageChannel() {
-    var controller = StreamChannelController<Object?>(sync: true);
-    var channel = MessageChannel();
-    window.parent!.postMessage('port', window.location.origin, [channel.port2]);
+import 'package:flutter_test/flutter_test.dart';
 
-    var portSubscription = channel.port1.onMessage.listen((message) {
-      controller.local.sink.add(message.data);
-    });
-    controller.local.stream
-        .listen(channel.port1.postMessage, onDone: portSubscription.cancel);
+Map<String, WebTest> webTestMap = <String, WebTest>{
+  ${webTestPairs.join('\n')}
+};
 
-    return controller.foreign;
+Future<void> main() {
+  final WebTest? webTest = webTestMap[testSelector];
+  if (webTest == null) {
+    throw Exception('Web test for \${testSelector} not found');
   }
+  return runWebTest(webTest);
+}
   ''';
 }
 

packages/flutter_tools/templates/plugin/lib/projectName_web.dart.tmpl

@@ -2,9 +2,9 @@
 // of your plugin as a separate package, instead of inlining it in the same
 // package as the core of your plugin.
 // ignore: avoid_web_libraries_in_flutter
-import 'dart:html' as html show window;
 
 import 'package:flutter_web_plugins/flutter_web_plugins.dart';
+import 'package:web/web.dart' as web;
 
 import '{{projectName}}_platform_interface.dart';
 
@@ -20,7 +20,7 @@ class {{pluginDartClass}}Web extends {{pluginDartClass}}Platform {
   /// Returns a [String] containing the version of the platform.
   @override
   Future<String?> getPlatformVersion() async {
-    final version = html.window.navigator.userAgent;
+    final version = web.window.navigator.userAgent;
     return version;
   }
 }

packages/flutter_tools/templates/plugin_shared/pubspec.yaml.tmpl

@@ -13,6 +13,7 @@ dependencies:
 {{#web}}
   flutter_web_plugins:
     sdk: flutter
+  web: ^0.5.1
 {{/web}}
   plugin_platform_interface: ^2.0.2
 

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

@@ -87,11 +87,13 @@ void main() {
       buildInfo: const BuildInfo(BuildMode.debug, '', treeShakeIcons: false),
       webMemoryFS: WebMemoryFS(),
       fileSystem: fileSystem,
+      buildDirectory: fileSystem.directory('build'),
       logger: logger,
       chromiumLauncher: chromiumLauncher,
       artifacts: artifacts,
       processManager: processManager,
       webRenderer: WebRendererMode.canvaskit,
+      useWasm: false,
       serverFactory: () async => server,
       testPackageUri: Uri.parse('test'),
     );
@@ -134,11 +136,13 @@ void main() {
       ),
       webMemoryFS: WebMemoryFS(),
       fileSystem: fileSystem,
+      buildDirectory: fileSystem.directory('build'),
       logger: logger,
       chromiumLauncher: chromiumLauncher,
       artifacts: artifacts,
       processManager: processManager,
       webRenderer: WebRendererMode.canvaskit,
+      useWasm: false,
       serverFactory: () async => server,
       testPackageUri: Uri.parse('test'),
     );

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

@@ -1386,6 +1386,7 @@ class FakeFlutterTestRunner implements FlutterTestRunner {
     String? icudtlPath,
     Directory? coverageDirectory,
     bool web = false,
+    bool useWasm = false,
     String? randomSeed,
     String? reporter,
     String? fileReporter,

packages/flutter_tools/test/general.shard/test/web_test_compiler_test.dart

@@ -91,6 +91,7 @@ void main() {
       testFiles: <String>['project/test/fake_test.dart'],
       buildInfo: buildInfo,
       webRenderer: WebRendererMode.canvaskit,
+      useWasm: false,
     );
 
     expect(processManager.hasRemainingExpectations, isFalse);

packages/flutter_tools/test/general.shard/web/bootstrap_test.dart

@@ -138,37 +138,18 @@ void main() {
     expect(result, contains('el.setAttribute("data-main", \'foo.dart.js\');'));
   });
 
-  test('generateTestEntrypoint does not generate test config wrappers when testConfigPath is not passed', () {
+  test('generateTestEntrypoint generates proper imports and mappings for tests', () {
     final String result = generateTestEntrypoint(
-      relativeTestPath: 'relative_path.dart',
-      absolutePath: 'absolute_path.dart',
-      testConfigPath: null,
+      testInfos: <WebTestInfo>[
+        (entryPoint: 'foo.dart', goldensUri: Uri.parse('foo.dart'), configFile: null),
+        (entryPoint: 'bar.dart', goldensUri: Uri.parse('bar.dart'), configFile: 'bar_config.dart'),
+      ],
       languageVersion: LanguageVersion(2, 8),
     );
 
-    expect(result, isNot(contains('test_config.testExecutable')));
-  });
-
-  test('generateTestEntrypoint generates test config wrappers when testConfigPath is passed', () {
-    final String result = generateTestEntrypoint(
-      relativeTestPath: 'relative_path.dart',
-      absolutePath: 'absolute_path.dart',
-      testConfigPath: 'test_config_path.dart',
-      languageVersion: LanguageVersion(2, 8),
-    );
-
-    expect(result, contains('test_config.testExecutable'));
-  });
-
-  test('generateTestEntrypoint embeds urls correctly', () {
-    final String result = generateTestEntrypoint(
-      relativeTestPath: 'relative_path.dart',
-      absolutePath: '/test/absolute_path.dart',
-      testConfigPath: null,
-      languageVersion: LanguageVersion(2, 8),
-    );
-
-    expect(result, contains("Uri.parse('file:///test/absolute_path.dart')"));
+    expect(result, contains("import 'org-dartlang-app:///foo.dart'"));
+    expect(result, contains("import 'org-dartlang-app:///bar.dart'"));
+    expect(result, contains("import 'org-dartlang-app:///bar_config.dart'"));
   });
 
   group('Using the DDC module system', () {
@@ -299,38 +280,5 @@ void main() {
 
       expect(result, contains('el.setAttribute("data-main", \'foo.dart.js\');'));
     });
-
-    test('generateTestEntrypoint does not generate test config wrappers when testConfigPath is not passed', () {
-      final String result = generateTestEntrypoint(
-        relativeTestPath: 'relative_path.dart',
-        absolutePath: 'absolute_path.dart',
-        testConfigPath: null,
-        languageVersion: LanguageVersion(2, 8),
-      );
-
-      expect(result, isNot(contains('test_config.testExecutable')));
-    });
-
-    test('generateTestEntrypoint generates test config wrappers when testConfigPath is passed', () {
-      final String result = generateTestEntrypoint(
-        relativeTestPath: 'relative_path.dart',
-        absolutePath: 'absolute_path.dart',
-        testConfigPath: 'test_config_path.dart',
-        languageVersion: LanguageVersion(2, 8),
-      );
-
-      expect(result, contains('test_config.testExecutable'));
-    });
-
-    test('generateTestEntrypoint embeds urls correctly', () {
-      final String result = generateTestEntrypoint(
-        relativeTestPath: 'relative_path.dart',
-        absolutePath: '/test/absolute_path.dart',
-        testConfigPath: null,
-        languageVersion: LanguageVersion(2, 8),
-      );
-
-      expect(result, contains("Uri.parse('file:///test/absolute_path.dart')"));
-    });
   });
 }

packages/integration_test/example/integration_test/_example_test_web.dart

@@ -9,12 +9,11 @@
 // gestures. You can also use WidgetTester to find child widgets in the widget
 // tree, read text, and verify that the values of widget properties are correct.
 
-import 'dart:html' as html;
 import 'package:flutter/material.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:integration_test/integration_test.dart';
-
 import 'package:integration_test_example/main.dart' as app;
+import 'package:web/web.dart' as web;
 
 void main() {
   IntegrationTestWidgetsFlutterBinding.ensureInitialized();
@@ -31,7 +30,7 @@ void main() {
         (Widget widget) =>
             widget is Text &&
             widget.data!
-                .startsWith('Platform: ${html.window.navigator.platform}\n'),
+                .startsWith('Platform: ${web.window.navigator.platform}\n'),
       ),
       findsOneWidget,
     );

packages/integration_test/example/integration_test/_extended_test_web.dart

@@ -9,12 +9,12 @@
 // gestures. You can also use WidgetTester to find child widgets in the widget
 // tree, read text, and verify that the values of widget properties are correct.
 
-import 'dart:html' as html;
 import 'package:flutter/material.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:integration_test/integration_test.dart';
 
 import 'package:integration_test_example/main.dart' as app;
+import 'package:web/web.dart' as web;
 
 void main() {
   final IntegrationTestWidgetsFlutterBinding binding =
@@ -47,7 +47,7 @@ void main() {
         (Widget widget) =>
             widget is Text &&
             widget.data!
-                .startsWith('Platform: ${html.window.navigator.platform}\n'),
+                .startsWith('Platform: ${web.window.navigator.platform}\n'),
       ),
       findsOneWidget,
     );

packages/integration_test/example/integration_test/example_test.dart

@@ -11,7 +11,7 @@
 
 import 'package:integration_test/integration_test.dart';
 
-import '_example_test_io.dart' if (dart.library.html) '_example_test_web.dart' as tests;
+import '_example_test_io.dart' if (dart.library.js_interop) '_example_test_web.dart' as tests;
 
 void main() {
   IntegrationTestWidgetsFlutterBinding.ensureInitialized();

packages/integration_test/example/integration_test/extended_test.dart

@@ -13,7 +13,7 @@
 
 import 'package:integration_test/integration_test.dart';
 
-import '_extended_test_io.dart' if (dart.library.html) '_extended_test_web.dart' as tests;
+import '_extended_test_io.dart' if (dart.library.js_interop) '_extended_test_web.dart' as tests;
 
 void main() {
   IntegrationTestWidgetsFlutterBinding.ensureInitialized();

packages/integration_test/example/lib/main.dart

@@ -2,6 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'my_app.dart' if (dart.library.html) 'my_web_app.dart';
+import 'my_app.dart' if (dart.library.js_interop) 'my_web_app.dart';
 
 void main() => startApp();

packages/integration_test/example/lib/my_web_app.dart

@@ -2,9 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'dart:html' as html;
 import 'package:flutter/material.dart';
 
+import 'package:web/web.dart' as web;
+
 // ignore_for_file: public_member_api_docs
 
 void startApp() => runApp(const MyWebApp());
@@ -26,7 +27,7 @@ class _MyWebAppState extends State<MyWebApp> {
         ),
         body: Center(
           key: const Key('mainapp'),
-          child: Text('Platform: ${html.window.navigator.platform}\n'),
+          child: Text('Platform: ${web.window.navigator.platform}\n'),
         ),
       ),
     );

packages/integration_test/example/pubspec.yaml

@@ -11,6 +11,7 @@ dependencies:
     sdk: flutter
 
   cupertino_icons: 1.0.6
+  web: 0.5.1
 
   characters: 1.3.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   collection: 1.18.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
@@ -78,7 +79,6 @@ dev_dependencies:
   typed_data: 1.3.2 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   vm_service: 14.2.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   watcher: 1.1.0 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
-  web: 0.5.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   web_socket_channel: 2.4.4 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   webdriver: 3.0.3 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"
   webkit_inspection_protocol: 1.2.1 # THIS LINE IS AUTOGENERATED - TO UPDATE USE "flutter update-packages --force-upgrade"

packages/integration_test/lib/src/_callback_io.dart

@@ -15,7 +15,7 @@ import 'channel.dart';
 ///
 /// See also:
 ///
-///  * `_callback_web.dart`, which has the dart:html implementation
+///  * `_callback_web.dart`, which has the web implementation
 CallbackManager get callbackManager => _singletonCallbackManager;
 
 /// IOCallbackManager singleton.

packages/integration_test/lib/src/_callback_web.dart

@@ -6,7 +6,7 @@ import 'dart:async';
 
 import '../common.dart';
 
-/// The dart:html implementation of [CallbackManager].
+/// The web implementation of [CallbackManager].
 ///
 /// See also:
 ///

packages/integration_test/lib/src/_extension_io.dart

@@ -6,7 +6,7 @@
 ///
 /// See also:
 ///
-///  * `_extension_web.dart`, which has the dart:html implementation
+///  * `_extension_web.dart`, which has the web implementation
 void registerWebServiceExtension(
     Future<Map<String, dynamic>> Function(Map<String, String>) call) {
   throw UnsupportedError('Use registerServiceExtension instead');

packages/integration_test/lib/src/_extension_web.dart

@@ -4,9 +4,11 @@
 
 import 'dart:async';
 import 'dart:convert';
-import 'dart:html' as html;
-import 'dart:js';
-import 'dart:js_util' as js_util;
+import 'dart:js_interop';
+import 'dart:js_interop_unsafe';
+
+@JS('window')
+external JSObject get _window;
 
 /// The web implementation of [registerWebServiceExtension].
 ///
@@ -20,21 +22,25 @@ void registerWebServiceExtension(Future<Map<String, dynamic>> Function(Map<Strin
   // Define the result variable because packages/flutter_driver/lib/src/driver/web_driver.dart
   // checks for this value to become non-null when waiting for the result. If this value is
   // undefined at the time of the check, WebDriver throws an exception.
-  context[r'$flutterDriverResult'] = null;
+  _window.setProperty(r'$flutterDriverResult'.toJS, null);
 
-  js_util.setProperty(html.window, r'$flutterDriver', allowInterop((dynamic message) async {
-    try {
-      final Map<String, dynamic> messageJson = jsonDecode(message as String) as Map<String, dynamic>;
-      final Map<String, String> params = messageJson.cast<String, String>();
-      final Map<String, dynamic> result = await callback(params);
-      context[r'$flutterDriverResult'] = json.encode(result);
-    } catch (error, stackTrace) {
-      // Encode the error in the same format the FlutterDriver extension uses.
-      // See //packages/flutter_driver/lib/src/extension/extension.dart
-      context[r'$flutterDriverResult'] = json.encode(<String, dynamic>{
-        'isError': true,
-        'response': '$error\n$stackTrace',
-      });
-    }
-  }));
+  _window.setProperty(r'$flutterDriver'.toJS, (JSAny message) {
+    (() async {
+      try {
+        final Map<String, dynamic> messageJson = jsonDecode((message as JSString).toDart) as Map<String, dynamic>;
+        final Map<String, String> params = messageJson.cast<String, String>();
+        final Map<String, dynamic> result = await callback(params);
+        _window.setProperty(r'$flutterDriverResult'.toJS, json.encode(result).toJS);
+      } catch (error, stackTrace) {
+        // Encode the error in the same format the FlutterDriver extension uses.
+        // See //packages/flutter_driver/lib/src/extension/extension.dart
+        _window.setProperty(r'$flutterDriverResult'.toJS,
+          json.encode(<String, dynamic>{
+            'isError': true,
+            'response': '$error\n$stackTrace',
+          }).toJS
+        );
+      }
+    })();
+  }.toJS);
 }

packages/integration_test/lib/src/callback.dart

@@ -2,4 +2,4 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-export '_callback_io.dart' if (dart.library.html) '_callback_web.dart';
+export '_callback_io.dart' if (dart.library.js_interop) '_callback_web.dart';

packages/integration_test/lib/src/extension.dart

@@ -2,4 +2,4 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-export '_extension_io.dart' if (dart.library.html) '_extension_web.dart';
+export '_extension_io.dart' if (dart.library.js_interop) '_extension_web.dart';

packages/integration_test/test/web_extension_test.dart

@@ -5,19 +5,23 @@
 @Tags(<String>['web'])
 library;
 
-import 'dart:js' as js;
+import 'dart:js_interop';
+import 'dart:js_interop_unsafe';
 
 import 'package:flutter_test/flutter_test.dart';
 import 'package:integration_test/integration_test.dart';
 
+@JS('window')
+external JSObject get _window;
+
 void main() {
   IntegrationTestWidgetsFlutterBinding();
 
   test('IntegrationTestWidgetsFlutterBinding on the web should register certain global properties', () {
-    expect(js.context.hasProperty(r'$flutterDriver'), true);
-    expect(js.context[r'$flutterDriver'], isNotNull);
+    expect(_window.hasProperty(r'$flutterDriver'.toJS).toDart, true);
+    expect(_window.getProperty(r'$flutterDriver'.toJS), isNotNull);
 
-    expect(js.context.hasProperty(r'$flutterDriverResult'), true);
-    expect(js.context[r'$flutterDriverResult'], isNull);
+    expect(_window.hasProperty(r'$flutterDriverResult'.toJS).toDart, true);
+    expect(_window.getProperty(r'$flutterDriverResult'.toJS), isNull);
   });
 }