[ci] Run web tests in wasm (unit + integration). (#8111)

Adds CI configuration to run web integration tests (in the master channel) compiled to Wasm.

It also removes the `build-examples` step from web integration tests, in some isolated testing:

| platform tests shard | With build-examples | Without build-examples |
|---|-----|-----|
| 1 | 30m | 21m |
| 2 | 13m | 11m |
| 3 | 17m | 10m |

## Issues

* Fixes https://github.com/flutter/flutter/issues/151664

.ci.yaml

@@ -245,6 +245,38 @@ targets:
           "PACKAGE_SHARDING": "--shardIndex 1 --shardCount 2"
         }
 
+  # Wasm unit tests in master
+  - name: Linux_web web_dart_unit_test_wasm_shard_1 master
+    bringup: true
+    recipe: packages/packages
+    timeout: 60
+    properties:
+      add_recipes_cq: "true"
+      target_file: web_dart_unit_tests_wasm.yaml
+      channel: master
+      version_file: flutter_master.version
+      package_sharding: "--shardIndex 0 --shardCount 2"
+      env_variables: >-
+        {
+          "CHANNEL": "master",
+          "PACKAGE_SHARDING": "--shardIndex 0 --shardCount 2"
+        }
+
+  - name: Linux_web web_dart_unit_test_wasm_shard_2 master
+    bringup: true
+    recipe: packages/packages
+    timeout: 60
+    properties:
+      target_file: web_dart_unit_tests_wasm.yaml
+      channel: master
+      version_file: flutter_master.version
+      package_sharding: "--shardIndex 1 --shardCount 2"
+      env_variables: >-
+        {
+          "CHANNEL": "master",
+          "PACKAGE_SHARDING": "--shardIndex 1 --shardCount 2"
+        }
+
   - name: Linux analyze master
     recipe: packages/packages
     timeout: 30
@@ -846,6 +878,7 @@ targets:
           "CHANNEL": "stable"
         }
 
+  # JS integration tests in master
   - name: Linux_web web_platform_tests_shard_1 master
     recipe: packages/packages
     timeout: 60
@@ -888,6 +921,53 @@ targets:
           "PACKAGE_SHARDING": "--shardIndex 2 --shardCount 3"
         }
 
+  # Wasm integration tests in master
+  - name: Linux_web web_platform_tests_wasm_shard_1 master
+    bringup: true
+    recipe: packages/packages
+    timeout: 60
+    properties:
+      target_file: web_platform_tests_wasm.yaml
+      version_file: flutter_master.version
+      channel: master
+      package_sharding: "--shardIndex 0 --shardCount 3"
+      env_variables: >-
+        {
+          "CHANNEL": "master",
+          "PACKAGE_SHARDING": "--shardIndex 0 --shardCount 3"
+        }
+
+  - name: Linux_web web_platform_tests_wasm_shard_2 master
+    bringup: true
+    recipe: packages/packages
+    timeout: 60
+    properties:
+      target_file: web_platform_tests_wasm.yaml
+      version_file: flutter_master.version
+      channel: master
+      package_sharding: "--shardIndex 1 --shardCount 3"
+      env_variables: >-
+        {
+          "CHANNEL": "master",
+          "PACKAGE_SHARDING": "--shardIndex 1 --shardCount 3"
+        }
+
+  - name: Linux_web web_platform_tests_wasm_shard_3 master
+    bringup: true
+    recipe: packages/packages
+    timeout: 60
+    properties:
+      target_file: web_platform_tests_wasm.yaml
+      version_file: flutter_master.version
+      channel: master
+      package_sharding: "--shardIndex 2 --shardCount 3"
+      env_variables: >-
+        {
+          "CHANNEL": "master",
+          "PACKAGE_SHARDING": "--shardIndex 2 --shardCount 3"
+        }
+
+  # JS integration tests in stable
   - name: Linux_web web_platform_tests_shard_1 stable
     recipe: packages/packages
     timeout: 60

.ci/targets/web_dart_unit_tests.yaml

@@ -4,4 +4,8 @@ tasks:
     infra_step: true # Note infra steps failing prevents "always" from running.
   - name: Dart unit tests - web
     script: .ci/scripts/tool_runner.sh
-    args: ["dart-test", "--exclude=script/configs/dart_unit_tests_exceptions.yaml", "--platform=chrome"]
+    args: [
+      "dart-test",
+      "--platform=chrome",
+      "--exclude=script/configs/dart_unit_tests_exceptions.yaml"
+    ]

.ci/targets/web_dart_unit_tests_wasm.yaml

@@ -0,0 +1,13 @@
+tasks:
+  - name: prepare tool
+    script: .ci/scripts/prepare_tool.sh
+    infra_step: true # Note infra steps failing prevents "always" from running.
+  - name: Dart unit tests - web (wasm)
+    script: .ci/scripts/tool_runner.sh
+    args: [
+      "dart-test",
+      "--platform=chrome",
+      "--wasm",
+      "--exclude=script/configs/dart_unit_tests_exceptions.yaml",
+      "--exclude=script/configs/dart_unit_tests_wasm_exceptions.yaml"
+    ]

.ci/targets/web_platform_tests.yaml

@@ -6,9 +6,11 @@ tasks:
     script: .ci/scripts/tool_runner.sh
     args: ["fetch-deps", "--web", "--supporting-target-platforms-only"]
     infra_step: true
-  - name: build examples
-    script: .ci/scripts/tool_runner.sh
-    args: ["build-examples", "--web"]
   - name: drive examples
     script: .ci/scripts/tool_runner.sh
-    args: ["drive-examples", "--web", "--run-chromedriver", "--exclude=script/configs/exclude_integration_web.yaml"]
+    args: [
+      "drive-examples",
+      "--web",
+      "--run-chromedriver",
+      "--exclude=script/configs/exclude_integration_web.yaml",
+    ]

.ci/targets/web_platform_tests_wasm.yaml

@@ -0,0 +1,18 @@
+tasks:
+  - name: prepare tool
+    script: .ci/scripts/prepare_tool.sh
+    infra_step: true # Note infra steps failing prevents "always" from running.
+  - name: download Dart deps
+    script: .ci/scripts/tool_runner.sh
+    args: ["fetch-deps", "--web", "--supporting-target-platforms-only"]
+    infra_step: true
+  - name: drive examples
+    script: .ci/scripts/tool_runner.sh
+    args: [
+      "drive-examples",
+      "--web",
+      "--wasm",
+      "--run-chromedriver",
+      "--exclude=script/configs/exclude_integration_web.yaml",
+      "--exclude=script/configs/exclude_integration_web_wasm.yaml"
+    ]

packages/animations/.gitignore

@@ -31,9 +31,6 @@
 .pub/
 /build/
 
-# Web related
-lib/generated_plugin_registrant.dart
-
 # Symbolication related
 app.*.symbols
 

packages/animations/example/.gitignore

@@ -30,8 +30,5 @@
 .pub/
 /build/
 
-# Web related
-lib/generated_plugin_registrant.dart
-
 # Exceptions to above rules.
 !/packages/flutter_tools/test/data/dart_dependencies_test/**/.packages

packages/google_adsense/example/integration_test/experimental_ad_unit_widget_test.dart

@@ -205,7 +205,8 @@ Future<void> pumpAdWidget(Widget adUnit, WidgetTester tester) async {
 
   // This extra pump is needed for the platform view to actually render in the DOM.
   await tester.pump();
-
+  // One more for skwasm.
+  await tester.pump();
   // This extra pump is needed to simulate the async behavior of the adsense JS mock.
   await tester.pumpAndSettle();
 }

packages/google_maps_flutter/google_maps_flutter_web/example/integration_test/shape_test.dart

@@ -232,11 +232,11 @@ void main() {
           visualization.HeatmapLayerOptions()
             ..data = <gmaps.LatLng>[gmaps.LatLng(0, 0)].toJS;
 
-      expect(heatmap.data, hasLength(0));
+      expect(heatmap.data.array.toDart, hasLength(0));
 
       controller.update(options);
 
-      expect(heatmap.data, hasLength(1));
+      expect(heatmap.data.array.toDart, hasLength(1));
     });
 
     group('remove', () {

packages/google_maps_flutter/google_maps_flutter_web/example/integration_test/shapes_test.dart

@@ -435,7 +435,7 @@ void main() {
       controller.addHeatmaps(heatmaps);
 
       expect(
-        controller.heatmaps[const HeatmapId('1')]?.heatmap?.data,
+        controller.heatmaps[const HeatmapId('1')]!.heatmap!.data.array.toDart,
         hasLength(0),
       );
 
@@ -450,7 +450,7 @@ void main() {
 
       expect(controller.heatmaps.length, 1);
       expect(
-        controller.heatmaps[const HeatmapId('1')]?.heatmap?.data,
+        controller.heatmaps[const HeatmapId('1')]!.heatmap!.data.array.toDart,
         hasLength(1),
       );
     });
@@ -510,7 +510,9 @@ void main() {
           controller.heatmaps.values.first.heatmap!;
 
       expect(
-        heatmap.get('gradient'),
+        (heatmap.get('gradient')! as JSArray<JSString>)
+            .toDart
+            .map((JSString? value) => value!.toDart),
         <String>['rgba(250, 186, 218, 0.00)', 'rgba(250, 186, 218, 1.00)'],
       );
     });

packages/image_picker/image_picker_platform_interface/CHANGELOG.md

@@ -1,6 +1,7 @@
-## NEXT
+## 2.10.1
 
 * Updates minimum supported SDK version to Flutter 3.22/Dart 3.4.
+* Fixes Wasm tests in internal PickedFile implementation.
 
 ## 2.10.0
 

packages/image_picker/image_picker_platform_interface/lib/src/types/picked_file/picked_file.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.
 
+// TODO(dit): Remove this, https://github.com/flutter/flutter/issues/144286
+
 export 'lost_data.dart';
 export 'unsupported.dart'
-    if (dart.library.html) 'html.dart'
+    if (dart.library.js_interop) 'html.dart'
     if (dart.library.io) 'io.dart';

packages/image_picker/image_picker_platform_interface/pubspec.yaml

@@ -4,7 +4,7 @@ repository: https://github.com/flutter/packages/tree/main/packages/image_picker/
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+image_picker%22
 # NOTE: We strongly prefer non-breaking changes, even at the expense of a
 # less-clean API. See https://flutter.dev/go/platform-interface-breaking-changes
-version: 2.10.0
+version: 2.10.1
 
 environment:
   sdk: ^3.4.0
@@ -20,6 +20,7 @@ dependencies:
 dev_dependencies:
   flutter_test:
     sdk: flutter
+  web: ^1.1.0
 
 topics:
   - image-picker

packages/image_picker/image_picker_platform_interface/test/picked_file_html_test.dart

@@ -6,15 +6,18 @@
 library;
 
 import 'dart:convert';
-import 'dart:html' as html;
+import 'dart:js_interop';
+import 'dart:typed_data';
 
 import 'package:flutter_test/flutter_test.dart';
 import 'package:image_picker_platform_interface/image_picker_platform_interface.dart';
+import 'package:web/web.dart' as web;
 
 const String expectedStringContents = 'Hello, world!';
-final List<int> bytes = utf8.encode(expectedStringContents);
-final html.File textFile = html.File(<List<int>>[bytes], 'hello.txt');
-final String textFileUrl = html.Url.createObjectUrl(textFile);
+final Uint8List bytes = utf8.encode(expectedStringContents);
+final web.File textFile =
+    web.File(<JSUint8Array>[bytes.toJS].toJS, 'hello.txt');
+final String textFileUrl = web.URL.createObjectURL(textFile);
 
 void main() {
   group('Create with an objectUrl', () {

packages/pointer_interceptor/pointer_interceptor_web/example/integration_test/widget_test.dart

@@ -70,7 +70,8 @@ Future<void> _fullyRenderApp(WidgetTester tester) async {
   await tester.pumpWidget(const app.MyApp());
   // Pump 2 frames so the framework injects the platform view into the DOM.
   await tester.pump();
-  await tester.pump();
+  // Give the browser some time to perform DOM operations (for Wasm code)
+  await tester.pump(const Duration(milliseconds: 500));
 }
 
 // Calls [_getHtmlElementAt] passing it the center of the widget identified by

packages/rfw/test/material_widgets_test.dart

@@ -13,6 +13,12 @@ import 'tolerant_comparator.dart'
     if (dart.library.js_interop) 'tolerant_comparator_web.dart';
 import 'utils.dart';
 
+/// A const to tell apart Wasm from JS web.
+///
+/// This is used below to do comparisons of numbers, where in JS a whole double
+/// is serialized as "2", in Wasm (and non-web platforms) it's "2.0".
+const bool kIsJS = kIsWeb && !kIsWasm;
+
 void main() {
   const LibraryName coreName = LibraryName(<String>['core']);
   const LibraryName materialName = LibraryName(<String>['material']);
@@ -229,7 +235,7 @@ void main() {
     await tester.pumpAndSettle();
     expect(eventLog, contains('menu_item {args: second}'));
     expect(eventLog,
-        contains(kIsWeb ? 'dropdown {value: 2}' : 'dropdown {value: 2.0}'));
+        contains(kIsJS ? 'dropdown {value: 2}' : 'dropdown {value: 2.0}'));
 
     await tester.tapAt(const Offset(20.0, 20.0));
     await tester.pump();
@@ -682,15 +688,15 @@ void main() {
     await _slideToValue(tester, sliderFinder, 20.0);
     await tester.pumpAndSettle();
     expect(eventLog,
-        contains(kIsWeb ? 'slider {value: 20}' : 'slider {value: 20.0}'));
+        contains(kIsJS ? 'slider {value: 20}' : 'slider {value: 20.0}'));
     expect(
         eventLog,
         contains(
-            kIsWeb ? 'slider.start {value: 0}' : 'slider.start {value: 0.0}'));
+            kIsJS ? 'slider.start {value: 0}' : 'slider.start {value: 0.0}'));
     expect(
         eventLog,
         contains(
-            kIsWeb ? 'slider.end {value: 20}' : 'slider.end {value: 20.0}'));
+            kIsJS ? 'slider.end {value: 20}' : 'slider.end {value: 20.0}'));
   });
 }
 

packages/url_launcher/url_launcher_web/example/integration_test/link_widget_test.dart

@@ -34,6 +34,7 @@ void main() {
       ));
       // Platform view creation happens asynchronously.
       await tester.pumpAndSettle();
+      await tester.pump();
 
       final html.Element anchor = _findSingleAnchor();
       expect(anchor.getAttribute('href'), uri.toString());
@@ -51,6 +52,7 @@ void main() {
         )),
       ));
       await tester.pumpAndSettle();
+      await tester.pump();
 
       // Check that the same anchor has been updated.
       expect(anchor.getAttribute('href'), uri2.toString());
@@ -68,6 +70,7 @@ void main() {
         )),
       ));
       await tester.pumpAndSettle();
+      await tester.pump();
 
       // Check that internal route properly prepares using the default
       // [UrlStrategy]
@@ -102,6 +105,7 @@ void main() {
         ),
       ));
       await tester.pumpAndSettle();
+      await tester.pump();
 
       final Size containerSize = tester.getSize(find.byKey(containerKey));
       // The Stack widget inserted by the `WebLinkDelegate` shouldn't loosen the
@@ -130,6 +134,7 @@ void main() {
       ));
       // Platform view creation happens asynchronously.
       await tester.pumpAndSettle();
+      await tester.pump();
 
       final html.Element anchor = _findSingleAnchor();
       expect(anchor.hasAttribute('href'), false);
@@ -161,6 +166,7 @@ void main() {
       );
 
       await tester.pumpAndSettle();
+      await tester.pump();
 
       await tester.scrollUntilVisible(
         find.text('#${itemCount - 1}'),
@@ -213,6 +219,7 @@ void main() {
       ));
       // Platform view creation happens asynchronously.
       await tester.pumpAndSettle();
+      await tester.pump();
 
       expect(observer.currentRouteName, '/');
       expect(testPlugin.launches, isEmpty);
@@ -227,10 +234,6 @@ void main() {
       // should be no calls to `launchUrl`.
       expect(observer.currentRouteName, '/foobar');
       expect(testPlugin.launches, isEmpty);
-
-      // Needed when testing on on Chrome98 headless in CI.
-      // See https://github.com/flutter/flutter/issues/121161
-      await tester.pumpAndSettle();
     });
 
     testWidgets('keydown to navigate to internal link',
@@ -258,6 +261,7 @@ void main() {
       ));
       // Platform view creation happens asynchronously.
       await tester.pumpAndSettle();
+      await tester.pump();
 
       expect(observer.currentRouteName, '/');
       expect(testPlugin.launches, isEmpty);
@@ -272,10 +276,6 @@ void main() {
       // should be no calls to `launchUrl`.
       expect(observer.currentRouteName, '/foobar');
       expect(testPlugin.launches, isEmpty);
-
-      // Needed when testing on on Chrome98 headless in CI.
-      // See https://github.com/flutter/flutter/issues/121161
-      await tester.pumpAndSettle();
     });
 
     testWidgets('click to navigate to external link',
@@ -300,6 +300,7 @@ void main() {
       ));
       // Platform view creation happens asynchronously.
       await tester.pumpAndSettle();
+      await tester.pump();
 
       expect(observer.currentRouteName, '/');
       expect(testPlugin.launches, isEmpty);
@@ -315,10 +316,6 @@ void main() {
       // no calls to `launchUrl`.
       expect(observer.currentRouteName, '/');
       expect(testPlugin.launches, isEmpty);
-
-      // Needed when testing on on Chrome98 headless in CI.
-      // See https://github.com/flutter/flutter/issues/121161
-      await tester.pumpAndSettle();
     });
 
     testWidgets('keydown to navigate to external link',
@@ -343,6 +340,7 @@ void main() {
       ));
       // Platform view creation happens asynchronously.
       await tester.pumpAndSettle();
+      await tester.pump();
 
       expect(observer.currentRouteName, '/');
       expect(testPlugin.launches, isEmpty);
@@ -357,17 +355,13 @@ void main() {
       // `launchUrl`, and there's no change to the app's route name.
       expect(observer.currentRouteName, '/');
       expect(testPlugin.launches, <String>['https://google.com']);
-
-      // Needed when testing on on Chrome98 headless in CI.
-      // See https://github.com/flutter/flutter/issues/121161
-      await tester.pumpAndSettle();
     });
   });
 }
 
 html.Element _findSingleAnchor() {
   final List<html.Element> foundAnchors = <html.Element>[];
-  html.NodeList anchors = html.document.querySelectorAll('a');
+  final html.NodeList anchors = html.document.querySelectorAll('a');
   for (int i = 0; i < anchors.length; i++) {
     final html.Element anchor = anchors.item(i)! as html.Element;
     if (anchor.hasProperty(linkViewIdProperty.toJS).toDart) {
@@ -375,27 +369,24 @@ html.Element _findSingleAnchor() {
     }
   }
 
-  // Search inside the shadow DOM as well.
-  final html.ShadowRoot? shadowRoot =
-      html.document.querySelector('flt-glass-pane')?.shadowRoot;
-  if (shadowRoot != null) {
-    anchors = shadowRoot.querySelectorAll('a');
-    for (int i = 0; i < anchors.length; i++) {
-      final html.Element anchor = anchors.item(i)! as html.Element;
-      if (anchor.hasProperty(linkViewIdProperty.toJS).toDart) {
-        foundAnchors.add(anchor);
-      }
-    }
-  }
-
   return foundAnchors.single;
 }
 
 void _simulateClick(html.Element target) {
+  // Stop the browser from navigating away from the test suite.
+  target.addEventListener(
+      'click',
+      (html.Event e) {
+        e.preventDefault();
+      }.toJS);
+  // Synthesize a click event.
   target.dispatchEvent(
     html.MouseEvent(
       'click',
-      html.MouseEventInit()..bubbles = true,
+      html.MouseEventInit(
+        bubbles: true,
+        cancelable: true,
+      ),
     ),
   );
 }
@@ -404,7 +395,11 @@ void _simulateKeydown(html.Element target) {
   target.dispatchEvent(
     html.KeyboardEvent(
       'keydown',
-      html.KeyboardEventInit()..bubbles = true,
+      html.KeyboardEventInit(
+        bubbles: true,
+        cancelable: true,
+        code: 'Space',
+      ),
     ),
   );
 }

packages/vector_graphics_codec/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 1.1.13
+
+* Works around a subtle Wasm bug in `writeRadialGradient`.
+
 ## 1.1.12
 
 * Transfers the package source from https://github.com/dnfield/vector_graphics

packages/vector_graphics_codec/lib/vector_graphics_codec.dart

@@ -394,10 +394,10 @@ class VectorGraphicsCodec {
     buffer._putFloat32(centerY);
     buffer._putFloat32(radius);
 
-    if (focalX != null) {
+    if (focalX != null && focalY != null) {
       buffer._putUint8(1);
       buffer._putFloat32(focalX);
-      buffer._putFloat32(focalY!);
+      buffer._putFloat32(focalY);
     } else {
       buffer._putUint8(0);
     }
@@ -710,7 +710,7 @@ class VectorGraphicsCodec {
     return id;
   }
 
-  /// Write a new path to the [buffer], returing the identifier
+  /// Write a new path to the [buffer], returning the identifier
   /// assigned to it.
   ///
   /// The [fillType] argument is either `1` for a fill or `0` for a stroke.

packages/vector_graphics_codec/pubspec.yaml

@@ -2,7 +2,7 @@ name: vector_graphics_codec
 description: An encoding library for the binary format used in `package:vector_graphics`
 repository: https://github.com/flutter/packages/tree/main/packages/vector_graphics_codec
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+vector_graphics%22
-version: 1.1.12
+version: 1.1.13
 
 environment:
   sdk: ^3.4.0

packages/video_player/video_player/example/integration_test/video_player_test.dart

@@ -199,6 +199,10 @@ void main() {
         expect(controller.value.position,
             lessThanOrEqualTo(controller.value.duration));
       },
+      // Flaky on the web, headless browsers don't like to seek to non-buffered
+      // positions of a video (and since this isn't even injecting the video
+      // element on the page, the video never starts buffering with the test)
+      skip: kIsWeb,
     );
 
     testWidgets('test video player view with local asset',

script/configs/dart_unit_tests_wasm_exceptions.yaml

@@ -0,0 +1,10 @@
+# Packages that are excluded from dart unit tests (compiled to Wasm)
+# 
+# This list should be kept as short as possible, and things should remain here
+# only as long as necessary, since in general all web packages should work with
+# Wasm.
+#
+# This is only used for the rare case where a package fails in Wasm, but works
+# in JS mode.
+
+[] # Needed so the contents of this file are an empty array, not `null`!

script/configs/exclude_all_packages_app_wasm.yaml

@@ -1,8 +1,8 @@
 # This list should be kept as short as possible, and things should remain here
 # only as long as necessary, since in general the goal is for all of the latest
 # versions of packages to be mutually compatible, and compilable with Wasm.
-
-# This is only used for wasm compilation. Once all packages in the repo have
-# been migrated, remove this file and use `exclude_all_packages_app.yaml` only.
+#
+# This is only used for the rare case where a package fails in Wasm, but works
+# in JS mode.
 
 [] # Needed so the contents of this file are an empty array, not `null`!

script/configs/exclude_integration_web_wasm.yaml

@@ -0,0 +1,8 @@
+# This list should be kept as short as possible, and things should remain here
+# only as long as necessary, since in general all web packages should work with
+# Wasm.
+#
+# This is only used for the rare case where a package fails in Wasm, but works
+# in JS mode.
+
+[] # Needed so the contents of this file are an empty array, not `null`!

script/tool/lib/src/dart_test_command.dart

@@ -41,6 +41,8 @@ class DartTestCommand extends PackageLoopingCommand {
       help: 'Runs tests on the given platform instead of the default platform '
           '("vm" in most cases, "chrome" for web plugin implementations).',
     );
+    argParser.addFlag(kWebWasmFlag,
+        help: 'Compile to WebAssembly rather than JavaScript');
   }
 
   static const String _platformFlag = 'platform';
@@ -108,18 +110,21 @@ class DartTestCommand extends PackageLoopingCommand {
       platform = 'chrome';
     }
 
+    // Whether to run web tests compiled to wasm.
+    final bool wasm = platform != 'vm' && getBoolArg(kWebWasmFlag);
+
     bool passed;
     if (package.requiresFlutter()) {
-      passed = await _runFlutterTests(package, platform: platform);
+      passed = await _runFlutterTests(package, platform: platform, wasm: wasm);
     } else {
-      passed = await _runDartTests(package, platform: platform);
+      passed = await _runDartTests(package, platform: platform, wasm: wasm);
     }
     return passed ? PackageResult.success() : PackageResult.fail();
   }
 
   /// Runs the Dart tests for a Flutter package, returning true on success.
   Future<bool> _runFlutterTests(RepositoryPackage package,
-      {String? platform}) async {
+      {String? platform, bool wasm = false}) async {
     final String experiment = getStringArg(kEnableExperiment);
 
     final int exitCode = await processRunner.runAndStream(
@@ -131,6 +136,7 @@ class DartTestCommand extends PackageLoopingCommand {
         // Flutter defaults to VM mode (under a different name) and explicitly
         // setting it is deprecated, so pass nothing in that case.
         if (platform != null && platform != 'vm') '--platform=$platform',
+        if (wasm) '--wasm',
       ],
       workingDir: package.directory,
     );
@@ -139,7 +145,7 @@ class DartTestCommand extends PackageLoopingCommand {
 
   /// Runs the Dart tests for a non-Flutter package, returning true on success.
   Future<bool> _runDartTests(RepositoryPackage package,
-      {String? platform}) async {
+      {String? platform, bool wasm = false}) async {
     // Unlike `flutter test`, `dart run test` does not automatically get
     // packages
     if (!await runPubGet(package, processRunner, super.platform)) {
@@ -156,6 +162,7 @@ class DartTestCommand extends PackageLoopingCommand {
         if (experiment.isNotEmpty) '--enable-experiment=$experiment',
         'test',
         if (platform != null) '--platform=$platform',
+        if (wasm) '--compiler=dart2wasm',
       ],
       workingDir: package.directory,
     );

script/tool/test/dart_test_command_test.dart

@@ -337,6 +337,33 @@ test_on: vm && browser
       );
     });
 
+    test('runs in Chrome (wasm) when requested for Flutter package', () async {
+      final RepositoryPackage package = createFakePackage(
+        'a_package',
+        packagesDir,
+        isFlutter: true,
+        extraFiles: <String>['test/empty_test.dart'],
+      );
+
+      await runCapturingPrint(
+          runner, <String>['dart-test', '--platform=chrome', '--wasm']);
+
+      expect(
+        processRunner.recordedCalls,
+        orderedEquals(<ProcessCall>[
+          ProcessCall(
+              getFlutterCommand(mockPlatform),
+              const <String>[
+                'test',
+                '--color',
+                '--platform=chrome',
+                '--wasm',
+              ],
+              package.path),
+        ]),
+      );
+    });
+
     test('runs in Chrome by default for Flutter plugins that implement web',
         () async {
       final RepositoryPackage plugin = createFakePlugin(
@@ -517,6 +544,33 @@ test_on: vm && browser
       );
     });
 
+    test('runs in Chrome (wasm) when requested for Dart package', () async {
+      final RepositoryPackage package = createFakePackage(
+        'package',
+        packagesDir,
+        extraFiles: <String>['test/empty_test.dart'],
+      );
+
+      await runCapturingPrint(
+          runner, <String>['dart-test', '--platform=chrome', '--wasm']);
+
+      expect(
+        processRunner.recordedCalls,
+        orderedEquals(<ProcessCall>[
+          ProcessCall('dart', const <String>['pub', 'get'], package.path),
+          ProcessCall(
+              'dart',
+              const <String>[
+                'run',
+                'test',
+                '--platform=chrome',
+                '--compiler=dart2wasm',
+              ],
+              package.path),
+        ]),
+      );
+    });
+
     test('skips running in browser mode if package opts out', () async {
       final RepositoryPackage package = createFakePackage(
         'a_package',