[ci] Add LUCI web platform tests

.ci.yaml

@@ -281,6 +281,50 @@ targets:
       target_file: web_build_all_packages.yaml
       channel: stable
 
+  - name: Linux_web web_platform_tests_shard_1 master
+    bringup: true # New target
+    recipe: packages/packages
+    timeout: 60
+    properties:
+      target_file: web_platform_tests.yaml
+      cores: "32"
+      version_file: flutter_master.version
+      channel: master
+      package_sharding: "--shardIndex 0 --shardCount 2"
+
+  - name: Linux_web web_platform_tests_shard_2 master
+    bringup: true # New target
+    recipe: packages/packages
+    timeout: 60
+    properties:
+      target_file: web_platform_tests.yaml
+      cores: "32"
+      version_file: flutter_master.version
+      channel: master
+      package_sharding: "--shardIndex 1 --shardCount 2"
+
+  - name: Linux_web web_platform_tests_shard_1 stable
+    bringup: true # New target
+    recipe: packages/packages
+    timeout: 60
+    properties:
+      target_file: web_platform_tests.yaml
+      cores: "32"
+      version_file: flutter_stable.version
+      channel: stable
+      package_sharding: "--shardIndex 0 --shardCount 2"
+
+  - name: Linux_web web_platform_tests_shard_2 stable
+    bringup: true # New target
+    recipe: packages/packages
+    timeout: 60
+    properties:
+      target_file: web_platform_tests.yaml
+      cores: "32"
+      version_file: flutter_stable.version
+      channel: stable
+      package_sharding: "--shardIndex 1 --shardCount 2"
+
   ### Linux desktop tasks
   - name: Linux_desktop build_all_packages master
     recipe: packages/packages

.ci/targets/web_platform_tests.yaml

@@ -0,0 +1,9 @@
+tasks:
+  - name: prepare tool
+    script: .ci/scripts/prepare_tool.sh
+  - name: build examples
+    script: script/tool_runner.sh
+    args: ["build-examples", "--web"]
+  - name: drive examples
+    script: script/tool_runner.sh
+    args: ["drive-examples", "--web", "--run-chromedriver", "--exclude=script/configs/exclude_integration_web.yaml"]

script/tool/lib/src/drive_examples_command.dart

@@ -2,6 +2,7 @@
 // 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:convert';
 import 'dart:io';
 
@@ -17,6 +18,9 @@ import 'common/repository_package.dart';
 const int _exitNoPlatformFlags = 2;
 const int _exitNoAvailableDevice = 3;
 
+// From https://docs.flutter.dev/testing/integration-tests#running-in-a-browser
+const int _chromeDriverPort = 4444;
+
 /// A command to run the integration tests for a package's example applications.
 class DriveExamplesCommand extends PackageLoopingCommand {
   /// Creates an instance of the drive command.
@@ -44,8 +48,13 @@ class DriveExamplesCommand extends PackageLoopingCommand {
       help:
           'Runs the driver tests in Dart VM with the given experiments enabled.',
     );
+    argParser.addFlag(_chromeDriverFlag,
+        help: 'Runs chromedriver for the duration of the test.\n\n'
+            'Requires the correct version of chromedriver to be in your path.');
   }
 
+  static const String _chromeDriverFlag = 'run-chromedriver';
+
   @override
   final String name = 'drive-examples';
 
@@ -197,6 +206,12 @@ class DriveExamplesCommand extends PackageLoopingCommand {
 
       testsRan = true;
       if (useFlutterDrive) {
+        Process? chromedriver;
+        if (getBoolArg(_chromeDriverFlag)) {
+          print('Starting chromedriver on port $_chromeDriverPort');
+          chromedriver = await processRunner
+              .start('chromedriver', <String>['--port=$_chromeDriverPort']);
+        }
         for (final File driver in drivers) {
           final List<File> failingTargets = await _driveTests(
               example, driver, testTargets,
@@ -206,6 +221,10 @@ class DriveExamplesCommand extends PackageLoopingCommand {
                 getRelativePosixPath(failingTarget, from: package.directory));
           }
         }
+        if (chromedriver != null) {
+          print('Stopping chromedriver');
+          chromedriver.kill();
+        }
       } else {
         if (!await _runTests(example, deviceFlags: deviceFlags)) {
           errors.add('Integration tests failed.');

script/tool/test/drive_examples_command_test.dart

@@ -520,6 +520,54 @@ void main() {
           ]));
     });
 
+    test('runs chromedriver when requested', () async {
+      final RepositoryPackage plugin = createFakePlugin(
+        'plugin',
+        packagesDir,
+        extraFiles: <String>[
+          'example/integration_test/plugin_test.dart',
+          'example/test_driver/integration_test.dart',
+          'example/web/index.html',
+        ],
+        platformSupport: <String, PlatformDetails>{
+          platformWeb: const PlatformDetails(PlatformSupport.inline),
+        },
+      );
+
+      final Directory pluginExampleDirectory = getExampleDir(plugin);
+
+      final List<String> output = await runCapturingPrint(
+          runner, <String>['drive-examples', '--web', '--run-chromedriver']);
+
+      expect(
+        output,
+        containsAllInOrder(<Matcher>[
+          contains('Running for plugin'),
+          contains('No issues found!'),
+        ]),
+      );
+
+      expect(
+          processRunner.recordedCalls,
+          orderedEquals(<ProcessCall>[
+            const ProcessCall('chromedriver', <String>['--port=4444'], null),
+            ProcessCall(
+                getFlutterCommand(mockPlatform),
+                const <String>[
+                  'drive',
+                  '-d',
+                  'web-server',
+                  '--web-port=7357',
+                  '--browser-name=chrome',
+                  '--driver',
+                  'test_driver/integration_test.dart',
+                  '--target',
+                  'integration_test/plugin_test.dart',
+                ],
+                pluginExampleDirectory.path),
+          ]));
+    });
+
     test('drives a web plugin with CHROME_EXECUTABLE', () async {
       final RepositoryPackage plugin = createFakePlugin(
         'plugin',

script/tool/test/mocks.dart

@@ -79,6 +79,9 @@ class MockProcess extends Mock implements io.Process {
 
   @override
   IOSink get stdin => stdinMock;
+
+  @override
+  bool kill([io.ProcessSignal signal = io.ProcessSignal.sigterm]) => true;
 }
 
 class MockIOSink extends Mock implements IOSink {