Flutter preview device (#135639)

Fixes https://github.com/flutter/flutter/issues/130277

This PR does two things:

1. introduce a hidden `flutter build _preview` command, that will build a debug windows desktop app and copy it into the SDK's binary cache. This command is only intended to be run during packaging.
2. introduce a new device type, called `PreviewDevice`, which relies on the prebuilt desktop debug app from step 1, copies it into the target app's assets build folder, and then hot reloads their dart code into it.

packages/flutter_tools/lib/executable.dart

@@ -173,9 +173,11 @@ List<FlutterCommand> generateCommands({
     fileSystem: globals.fs,
   ),
   BuildCommand(
+    artifacts: globals.artifacts!,
     fileSystem: globals.fs,
     buildSystem: globals.buildSystem,
     osUtils: globals.os,
+    processUtils: globals.processUtils,
     verboseHelp: verboseHelp,
     androidSdk: globals.androidSdk,
     logger: globals.logger,

packages/flutter_tools/lib/src/artifacts.dart

@@ -69,6 +69,9 @@ enum Artifact {
 
   /// The location of file generators.
   flutterToolsFileGenerators,
+
+  /// Pre-built desktop debug app.
+  flutterPreviewDevice,
 }
 
 /// A subset of [Artifact]s that are platform and build mode independent
@@ -213,6 +216,8 @@ String? _artifactToFileName(Artifact artifact, Platform hostPlatform, [ BuildMod
       return 'const_finder.dart.snapshot';
     case Artifact.flutterToolsFileGenerators:
       return '';
+    case Artifact.flutterPreviewDevice:
+      return 'flutter_preview$exe';
   }
 }
 
@@ -573,6 +578,7 @@ class CachedArtifacts implements Artifacts {
       case Artifact.windowsCppClientWrapper:
       case Artifact.windowsDesktopPath:
       case Artifact.flutterToolsFileGenerators:
+      case Artifact.flutterPreviewDevice:
         return _getHostArtifactPath(artifact, platform, mode);
     }
   }
@@ -612,6 +618,7 @@ class CachedArtifacts implements Artifacts {
       case Artifact.windowsCppClientWrapper:
       case Artifact.windowsDesktopPath:
       case Artifact.flutterToolsFileGenerators:
+      case Artifact.flutterPreviewDevice:
         return _getHostArtifactPath(artifact, platform, mode);
     }
   }
@@ -663,6 +670,7 @@ class CachedArtifacts implements Artifacts {
       case Artifact.windowsCppClientWrapper:
       case Artifact.windowsDesktopPath:
       case Artifact.flutterToolsFileGenerators:
+      case Artifact.flutterPreviewDevice:
         return _getHostArtifactPath(artifact, platform, mode);
     }
   }
@@ -745,6 +753,9 @@ class CachedArtifacts implements Artifacts {
         throw StateError('Artifact $artifact not available for platform $platform.');
       case Artifact.flutterToolsFileGenerators:
         return _getFileGeneratorsPath();
+      case Artifact.flutterPreviewDevice:
+        assert(platform == TargetPlatform.windows_x64);
+        return _cache.getArtifactDirectory('flutter_preview').childFile('flutter_preview.exe').path;
     }
   }
 
@@ -1016,6 +1027,8 @@ class CachedLocalEngineArtifacts implements Artifacts {
         return _fileSystem.path.join(_getDartSdkPath(), 'bin', 'utils', artifactFileName);
       case Artifact.flutterToolsFileGenerators:
         return _getFileGeneratorsPath();
+      case Artifact.flutterPreviewDevice:
+        throw UnimplementedError('The preview device is not supported with local engine builds');
     }
   }
 
@@ -1118,7 +1131,6 @@ class CachedLocalWebSdkArtifacts implements Artifacts {
        _platform = platform,
        _operatingSystemUtils = operatingSystemUtils;
 
-
   final Artifacts _parent;
   final String _webSdkPath;
   final FileSystem _fileSystem;
@@ -1169,6 +1181,7 @@ class CachedLocalWebSdkArtifacts implements Artifacts {
         case Artifact.fontSubset:
         case Artifact.constFinder:
         case Artifact.flutterToolsFileGenerators:
+        case Artifact.flutterPreviewDevice:
           break;
       }
     }

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

@@ -5,11 +5,14 @@
 import 'package:meta/meta.dart';
 
 import '../android/android_sdk.dart';
+import '../artifacts.dart';
 import '../base/file_system.dart';
 import '../base/logger.dart';
 import '../base/os.dart';
+import '../base/process.dart';
 import '../build_info.dart';
 import '../build_system/build_system.dart';
+import '../cache.dart';
 import '../commands/build_linux.dart';
 import '../commands/build_macos.dart';
 import '../commands/build_windows.dart';
@@ -21,15 +24,18 @@ import 'build_bundle.dart';
 import 'build_ios.dart';
 import 'build_ios_framework.dart';
 import 'build_macos_framework.dart';
+import 'build_preview.dart';
 import 'build_web.dart';
 
 class BuildCommand extends FlutterCommand {
   BuildCommand({
+    required Artifacts artifacts,
     required FileSystem fileSystem,
     required BuildSystem buildSystem,
     required OperatingSystemUtils osUtils,
     required Logger logger,
     required AndroidSdk? androidSdk,
+    required ProcessUtils processUtils,
     bool verboseHelp = false,
   }){
     _addSubcommand(
@@ -67,6 +73,14 @@ class BuildCommand extends FlutterCommand {
       verboseHelp: verboseHelp
     ));
     _addSubcommand(BuildWindowsCommand(logger: logger, verboseHelp: verboseHelp));
+    _addSubcommand(BuildPreviewCommand(
+      artifacts: artifacts,
+      flutterRoot: Cache.flutterRoot!,
+      fs: fileSystem,
+      logger: logger,
+      processUtils: processUtils,
+      verboseHelp: verboseHelp,
+    ));
   }
 
   void _addSubcommand(BuildSubCommand command) {
@@ -90,14 +104,15 @@ class BuildCommand extends FlutterCommand {
 
 abstract class BuildSubCommand extends FlutterCommand {
   BuildSubCommand({
-    required Logger logger,
+    required this.logger,
     required bool verboseHelp
-  }): _logger = logger {
+  }) {
     requiresPubspecYaml();
     usesFatalWarningsOption(verboseHelp: verboseHelp);
   }
 
-  final Logger _logger;
+  @protected
+  final Logger logger;
 
   @override
   bool get reportNullSafety => true;
@@ -111,15 +126,15 @@ abstract class BuildSubCommand extends FlutterCommand {
   @protected
   void displayNullSafetyMode(BuildInfo buildInfo) {
     if (buildInfo.nullSafetyMode != NullSafetyMode.sound) {
-      _logger.printStatus('');
-      _logger.printStatus(
+      logger.printStatus('');
+      logger.printStatus(
         'Building without sound null safety ⚠️',
         emphasis: true,
       );
-      _logger.printStatus(
+      logger.printStatus(
         'Dart 3 will only support sound null safety, see https://dart.dev/null-safety',
       );
     }
-    _logger.printStatus('');
+    logger.printStatus('');
   }
 }

packages/flutter_tools/lib/src/commands/build_preview.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 'package:file/file.dart';
+
+import '../artifacts.dart';
+import '../base/common.dart';
+import '../base/io.dart';
+import '../base/process.dart';
+import '../build_info.dart';
+import '../cache.dart';
+import '../globals.dart' as globals;
+import '../project.dart';
+import '../runner/flutter_command.dart' show FlutterCommandResult;
+import '../windows/build_windows.dart';
+import 'build.dart';
+
+class BuildPreviewCommand extends BuildSubCommand {
+  BuildPreviewCommand({
+    required super.logger,
+    required bool verboseHelp,
+    required this.fs,
+    required this.flutterRoot,
+    required this.processUtils,
+    required this.artifacts,
+  }) : super(verboseHelp: verboseHelp) {
+    addCommonDesktopBuildOptions(verboseHelp: verboseHelp);
+  }
+
+  @override
+  final String name = '_preview';
+
+  @override
+  final bool hidden = true;
+
+  @override
+  Future<Set<DevelopmentArtifact>> get requiredArtifacts async => <DevelopmentArtifact>{
+    DevelopmentArtifact.windows,
+  };
+
+  @override
+  final String description = 'Build Flutter preview (desktop) app.';
+
+  final FileSystem fs;
+  final String flutterRoot;
+  final ProcessUtils processUtils;
+  final Artifacts artifacts;
+
+  static const BuildInfo buildInfo = BuildInfo(
+    BuildMode.debug,
+    null, // no flavor
+    // users may add icons later
+    treeShakeIcons: false,
+  );
+
+  @override
+  void requiresPubspecYaml() {}
+
+  static const String appName = 'flutter_preview';
+
+  @override
+  Future<FlutterCommandResult> runCommand() async {
+    if (!globals.platform.isWindows) {
+      throwToolExit('"build _preview" is currently only supported on Windows hosts.');
+    }
+    final Directory targetDir = fs.systemTempDirectory.createTempSync('flutter-build-preview');
+    try {
+      final FlutterProject flutterProject = await _createProject(targetDir);
+      await buildWindows(
+        flutterProject.windows,
+        buildInfo,
+      );
+
+      final File previewDevice = targetDir
+          .childDirectory(getWindowsBuildDirectory(TargetPlatform.windows_x64))
+          .childDirectory('runner')
+          .childDirectory('Debug')
+          .childFile('$appName.exe');
+      if (!previewDevice.existsSync()) {
+        throw StateError('Preview device not found at ${previewDevice.absolute.path}');
+      }
+      final String newPath = artifacts.getArtifactPath(Artifact.flutterPreviewDevice);
+      fs.file(newPath).parent.createSync(recursive: true);
+      previewDevice.copySync(newPath);
+      return FlutterCommandResult.success();
+    } finally {
+      try {
+        targetDir.deleteSync(recursive: true);
+      } on FileSystemException catch (exception) {
+        logger.printError('Failed to delete ${targetDir.path}\n\n$exception');
+      }
+    }
+  }
+
+  Future<FlutterProject> _createProject(Directory targetDir) async {
+    final List<String> cmd = <String>[
+      fs.path.join(flutterRoot, 'bin', 'flutter.bat'),
+      'create',
+      '--empty',
+      '--project-name',
+      'flutter_preview',
+      targetDir.path,
+    ];
+    final RunResult result = await processUtils.run(
+      cmd,
+      allowReentrantFlutter: true,
+    );
+    if (result.exitCode != 0) {
+      final StringBuffer buffer = StringBuffer('${cmd.join(' ')} exited with code ${result.exitCode}\n');
+      buffer.writeln('stdout:\n${result.stdout}\n');
+      buffer.writeln('stderr:\n${result.stderr}');
+      throw ProcessException(cmd.first, cmd.sublist(1), buffer.toString(), result.exitCode);
+    }
+    return FlutterProject.fromDirectory(targetDir);
+  }
+}

packages/flutter_tools/lib/src/features.dart

@@ -53,6 +53,9 @@ abstract class FeatureFlags {
   /// Whether native assets compilation and bundling is enabled.
   bool get isNativeAssetsEnabled => false;
 
+  /// Whether native assets compilation and bundling is enabled.
+  bool get isPreviewDeviceEnabled => true;
+
   /// Whether a particular feature is enabled for the current channel.
   ///
   /// Prefer using one of the specific getters above instead of this API.
@@ -72,6 +75,7 @@ const List<Feature> allFeatures = <Feature>[
   flutterWebWasm,
   cliAnimation,
   nativeAssets,
+  previewDevice,
 ];
 
 /// All current Flutter feature flags that can be configured.
@@ -172,6 +176,19 @@ const Feature nativeAssets = Feature(
   ),
 );
 
+/// Enable Flutter preview prebuilt device.
+const Feature previewDevice = Feature(
+  name: 'Flutter preview prebuilt device',
+  configSetting: 'enable-flutter-preview',
+  environmentOverride: 'FLUTTER_PREVIEW_DEVICE',
+  master: FeatureChannelSetting(
+    available: true,
+  ),
+  beta: FeatureChannelSetting(
+    available: true,
+  ),
+);
+
 /// A [Feature] is a process for conditionally enabling tool features.
 ///
 /// All settings are optional, and if not provided will generally default to

packages/flutter_tools/lib/src/flutter_device_manager.dart

@@ -27,6 +27,7 @@ import 'macos/macos_device.dart';
 import 'macos/macos_ipad_device.dart';
 import 'macos/macos_workflow.dart';
 import 'macos/xcdevice.dart';
+import 'preview_device.dart';
 import 'tester/flutter_tester.dart';
 import 'version.dart';
 import 'web/web_device.dart';
@@ -104,6 +105,14 @@ class FlutterDeviceManager extends DeviceManager {
       fileSystem: fileSystem,
       operatingSystemUtils: operatingSystemUtils,
     ),
+    PreviewDeviceDiscovery(
+      platform: platform,
+      artifacts: artifacts,
+      fileSystem: fileSystem,
+      logger: logger,
+      processManager: processManager,
+      featureFlags: featureFlags,
+    ),
     LinuxDevices(
       platform: platform,
       featureFlags: featureFlags,

packages/flutter_tools/lib/src/flutter_features.dart

@@ -58,6 +58,9 @@ class FlutterFeatureFlags implements FeatureFlags {
   @override
   bool get isNativeAssetsEnabled => isEnabled(nativeAssets);
 
+  @override
+  bool get isPreviewDeviceEnabled => isEnabled(previewDevice);
+
   @override
   bool isEnabled(Feature feature) {
     final String currentChannel = _flutterVersion.channel;

packages/flutter_tools/lib/src/preview_device.dart

@@ -8,17 +8,18 @@ import 'package:meta/meta.dart';
 import 'package:process/process.dart';
 
 import 'application_package.dart';
+import 'artifacts.dart';
 import 'base/file_system.dart';
 import 'base/io.dart';
 import 'base/logger.dart';
 import 'base/platform.dart';
 import 'build_info.dart';
 import 'bundle_builder.dart';
-import 'cache.dart';
 import 'desktop_device.dart';
 import 'devfs.dart';
 import 'device.dart';
 import 'device_port_forwarder.dart';
+import 'features.dart';
 import 'project.dart';
 import 'protocol_discovery.dart';
 
@@ -28,30 +29,99 @@ BundleBuilder _defaultBundleBuilder() {
   return BundleBuilder();
 }
 
+class PreviewDeviceDiscovery extends DeviceDiscovery {
+  PreviewDeviceDiscovery({
+    required Platform platform,
+    required Artifacts artifacts,
+    required FileSystem fileSystem,
+    required Logger logger,
+    required ProcessManager processManager,
+    required FeatureFlags featureFlags,
+  }) : _artifacts = artifacts,
+       _logger = logger,
+       _processManager = processManager,
+       _fileSystem = fileSystem,
+       _platform = platform,
+       _features = featureFlags;
+
+  final Platform _platform;
+  final Artifacts _artifacts;
+  final Logger _logger;
+  final ProcessManager _processManager;
+  final FileSystem _fileSystem;
+  final FeatureFlags _features;
+
+  @override
+  bool get canListAnything => _platform.isWindows;
+
+  @override
+  bool get supportsPlatform => _platform.isWindows;
+
+  @override
+  List<String> get wellKnownIds => <String>['preview'];
+
+  @override
+  Future<List<Device>> devices({
+    Duration? timeout,
+    DeviceDiscoveryFilter? filter,
+  }) async {
+    final File previewBinary = _fileSystem.file(_artifacts.getArtifactPath(Artifact.flutterPreviewDevice));
+    if (!previewBinary.existsSync()) {
+      return const <Device>[];
+    }
+    final PreviewDevice device = PreviewDevice(
+      artifacts: _artifacts,
+      fileSystem: _fileSystem,
+      logger: _logger,
+      processManager: _processManager,
+      previewBinary: previewBinary,
+    );
+    final bool matchesRequirements;
+    if (!_features.isPreviewDeviceEnabled) {
+      matchesRequirements = false;
+    } else if (filter == null) {
+      matchesRequirements = true;
+    } else {
+      matchesRequirements = await filter.matchesRequirements(device);
+    }
+    return <Device>[
+      if (matchesRequirements)
+        device,
+    ];
+  }
+
+  @override
+  Future<List<Device>> discoverDevices({
+    Duration? timeout,
+    DeviceDiscoveryFilter? filter,
+  }) {
+    return devices();
+  }
+}
+
 /// A device type that runs a prebuilt desktop binary alongside a locally compiled kernel file.
-///
-/// This could be used to support debug local development without plugins on machines that
-/// have not completed the SDK setup. These features are not fully implemented and the
-/// device is not currently discoverable.
 class PreviewDevice extends Device {
   PreviewDevice({
-    required Platform platform,
     required ProcessManager processManager,
     required Logger logger,
     required FileSystem fileSystem,
+    required Artifacts artifacts,
+    required File previewBinary,
     @visibleForTesting BundleBuilderFactory builderFactory = _defaultBundleBuilder,
-  }) : _platform = platform,
+  }) : _previewBinary = previewBinary,
        _processManager = processManager,
        _logger = logger,
        _fileSystem = fileSystem,
        _bundleBuilderFactory = builderFactory,
+       _artifacts = artifacts,
        super('preview', ephemeral: false, category: Category.desktop, platformType: PlatformType.custom);
 
-  final Platform _platform;
   final ProcessManager _processManager;
   final Logger _logger;
   final FileSystem _fileSystem;
   final BundleBuilderFactory _bundleBuilderFactory;
+  final Artifacts _artifacts;
+  final File _previewBinary;
 
   @override
   void clearLogs() { }
@@ -116,7 +186,7 @@ class PreviewDevice extends Device {
       await _bundleBuilderFactory().build(
         buildInfo: debuggingOptions.buildInfo,
         mainPath: mainPath,
-        platform: TargetPlatform.tester,
+        platform: TargetPlatform.windows_x64,
         assetDirPath: getAssetBuildDirectory(),
       );
       copyDirectory(_fileSystem.directory(
@@ -128,13 +198,18 @@ class PreviewDevice extends Device {
     }
 
     // Merge with precompiled executable.
-    final Directory precompiledDirectory = _fileSystem.directory(_fileSystem.path.join(Cache.flutterRoot!, 'artifacts_temp', 'Debug'));
-    copyDirectory(precompiledDirectory, assetDirectory);
+    final String copiedPreviewBinaryPath = assetDirectory.childFile(_previewBinary.basename).path;
+    _previewBinary.copySync(copiedPreviewBinaryPath);
+
+    final String windowsPath = _artifacts
+      .getArtifactPath(Artifact.windowsDesktopPath, platform: TargetPlatform.windows_x64, mode: BuildMode.debug);
+    final File windowsDll = _fileSystem.file(_fileSystem.path.join(windowsPath, 'flutter_windows.dll'));
+    final File icu = _fileSystem.file(_fileSystem.path.join(windowsPath, 'icudtl.dat'));
+    windowsDll.copySync(assetDirectory.childFile('flutter_windows.dll').path);
+    icu.copySync(assetDirectory.childDirectory('data').childFile('icudtl.dat').path);
 
     final Process process = await _processManager.start(
-      <String>[
-        assetDirectory.childFile('splash').path,
-      ],
+      <String>[copiedPreviewBinaryPath],
     );
     _process = process;
     _logReader.initializeProcess(process);
@@ -169,10 +244,7 @@ class PreviewDevice extends Device {
 
   @override
   Future<TargetPlatform> get targetPlatform async {
-    if (_platform.isWindows) {
-      return TargetPlatform.windows_x64;
-    }
-    return TargetPlatform.tester;
+    return TargetPlatform.windows_x64;
   }
 
   @override

packages/flutter_tools/lib/src/windows/build_windows.dart

@@ -56,9 +56,10 @@ Future<void> buildWindows(WindowsProject windowsProject, BuildInfo buildInfo, {
 
   // TODO(pbo-linaro): Add support for windows-arm64 platform, https://github.com/flutter/flutter/issues/129807
   const TargetPlatform targetPlatform = TargetPlatform.windows_x64;
-  final Directory buildDirectory = globals.fs.directory(
-    getWindowsBuildDirectory(targetPlatform)
-  );
+  final Directory buildDirectory = globals.fs.directory(globals.fs.path.join(
+    projectPath,
+    getWindowsBuildDirectory(targetPlatform),
+  ));
 
   final List<ProjectMigrator> migrators = <ProjectMigrator>[
     CmakeCustomCommandMigration(windowsProject, globals.logger),

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

@@ -10,6 +10,7 @@ import 'package:flutter_tools/src/artifacts.dart';
 import 'package:flutter_tools/src/base/file_system.dart';
 import 'package:flutter_tools/src/base/logger.dart';
 import 'package:flutter_tools/src/base/platform.dart';
+import 'package:flutter_tools/src/base/process.dart';
 import 'package:flutter_tools/src/build_info.dart';
 import 'package:flutter_tools/src/build_system/build_system.dart';
 import 'package:flutter_tools/src/cache.dart';
@@ -65,7 +66,10 @@ void main() {
   late FileSystem fileSystem;
   late TestUsage usage;
   late FakeProcessManager fakeProcessManager;
+  late ProcessUtils processUtils;
+  late BufferLogger logger;
   late XcodeProjectInterpreter xcodeProjectInterpreter;
+  late Artifacts artifacts;
 
   setUpAll(() {
     Cache.disableLocking();
@@ -73,8 +77,14 @@ void main() {
 
   setUp(() {
     fileSystem = MemoryFileSystem.test();
+    artifacts = Artifacts.test(fileSystem: fileSystem);
+    logger = BufferLogger.test();
     usage = TestUsage();
     fakeProcessManager = FakeProcessManager.empty();
+    processUtils = ProcessUtils(
+      logger: logger,
+      processManager: fakeProcessManager,
+    );
     xcodeProjectInterpreter = FakeXcodeProjectInterpreter();
   });
 
@@ -139,10 +149,12 @@ STDERR STUFF
 
   testUsingContext('macOS build fails when there is no macos project', () async {
     final BuildCommand command = BuildCommand(
+      artifacts: artifacts,
       androidSdk: FakeAndroidSdk(),
       buildSystem: TestBuildSystem.all(BuildResult(success: true)),
-      fileSystem: MemoryFileSystem.test(),
-      logger: BufferLogger.test(),
+      fileSystem: fileSystem,
+      logger: logger,
+      processUtils: processUtils,
       osUtils: FakeOperatingSystemUtils(),
     );
     createCoreMockProjectFiles();
@@ -161,10 +173,12 @@ STDERR STUFF
 
   testUsingContext('macOS build successfully with renamed .xcodeproj/.xcworkspace files', () async {
     final BuildCommand command = BuildCommand(
+      artifacts: artifacts,
       androidSdk: FakeAndroidSdk(),
       buildSystem: TestBuildSystem.all(BuildResult(success: true)),
-      fileSystem: MemoryFileSystem.test(),
-      logger: BufferLogger.test(),
+      fileSystem: fileSystem,
+      logger: logger,
+      processUtils: processUtils,
       osUtils: FakeOperatingSystemUtils(),
     );
 
@@ -184,10 +198,12 @@ STDERR STUFF
 
   testUsingContext('macOS build fails on non-macOS platform', () async {
     final BuildCommand command = BuildCommand(
+      artifacts: artifacts,
       androidSdk: FakeAndroidSdk(),
       buildSystem: TestBuildSystem.all(BuildResult(success: true)),
-      fileSystem: MemoryFileSystem.test(),
-      logger: BufferLogger.test(),
+      fileSystem: fileSystem,
+      logger: logger,
+      processUtils: processUtils,
       osUtils: FakeOperatingSystemUtils(),
     );
     fileSystem.file('pubspec.yaml').createSync();
@@ -206,10 +222,12 @@ STDERR STUFF
 
   testUsingContext('macOS build fails when feature is disabled', () async {
     final BuildCommand command = BuildCommand(
+      artifacts: artifacts,
       androidSdk: FakeAndroidSdk(),
       buildSystem: TestBuildSystem.all(BuildResult(success: true)),
-      fileSystem: MemoryFileSystem.test(),
-      logger: BufferLogger.test(),
+      fileSystem: fileSystem,
+      logger: logger,
+      processUtils: processUtils,
       osUtils: FakeOperatingSystemUtils(),
     );
     fileSystem.file('pubspec.yaml').createSync();
@@ -228,10 +246,12 @@ STDERR STUFF
 
   testUsingContext('macOS build forwards error stdout to status logger error', () async {
     final BuildCommand command = BuildCommand(
+      artifacts: artifacts,
       androidSdk: FakeAndroidSdk(),
       buildSystem: TestBuildSystem.all(BuildResult(success: true)),
-      fileSystem: MemoryFileSystem.test(),
-      logger: BufferLogger.test(),
+      fileSystem: fileSystem,
+      logger: logger,
+      processUtils: processUtils,
       osUtils: FakeOperatingSystemUtils(),
     );
     createMinimalMockProjectFiles();
@@ -258,10 +278,12 @@ STDERR STUFF
 
   testUsingContext('macOS build invokes xcode build (debug)', () async {
     final BuildCommand command = BuildCommand(
+      artifacts: artifacts,
       androidSdk: FakeAndroidSdk(),
       buildSystem: TestBuildSystem.all(BuildResult(success: true)),
-      fileSystem: MemoryFileSystem.test(),
-      logger: BufferLogger.test(),
+      fileSystem: fileSystem,
+      logger: logger,
+      processUtils: processUtils,
       osUtils: FakeOperatingSystemUtils(),
     );
     createMinimalMockProjectFiles();
@@ -280,10 +302,12 @@ STDERR STUFF
 
   testUsingContext('macOS build invokes xcode build (debug) with verbosity', () async {
     final BuildCommand command = BuildCommand(
+      artifacts: artifacts,
       androidSdk: FakeAndroidSdk(),
       buildSystem: TestBuildSystem.all(BuildResult(success: true)),
-      fileSystem: MemoryFileSystem.test(),
-      logger: BufferLogger.test(),
+      fileSystem: fileSystem,
+      logger: logger,
+      processUtils: processUtils,
       osUtils: FakeOperatingSystemUtils(),
     );
     createMinimalMockProjectFiles();
@@ -303,10 +327,12 @@ STDERR STUFF
 
   testUsingContext('macOS build invokes xcode build (profile)', () async {
     final BuildCommand command = BuildCommand(
+      artifacts: artifacts,
       androidSdk: FakeAndroidSdk(),
       buildSystem: TestBuildSystem.all(BuildResult(success: true)),
-      fileSystem: MemoryFileSystem.test(),
-      logger: BufferLogger.test(),
+      fileSystem: fileSystem,
+      logger: logger,
+      processUtils: processUtils,
       osUtils: FakeOperatingSystemUtils(),
     );
     createMinimalMockProjectFiles();
@@ -326,10 +352,12 @@ STDERR STUFF
 
   testUsingContext('macOS build invokes xcode build (release)', () async {
     final BuildCommand command = BuildCommand(
+      artifacts: artifacts,
       androidSdk: FakeAndroidSdk(),
       buildSystem: TestBuildSystem.all(BuildResult(success: true)),
-      fileSystem: MemoryFileSystem.test(),
-      logger: BufferLogger.test(),
+      fileSystem: fileSystem,
+      logger: logger,
+      processUtils: processUtils,
       osUtils: FakeOperatingSystemUtils(),
     );
     createMinimalMockProjectFiles();
@@ -348,10 +376,12 @@ STDERR STUFF
 
   testUsingContext('macOS build supports standard desktop build options', () async {
     final BuildCommand command = BuildCommand(
+      artifacts: artifacts,
       androidSdk: FakeAndroidSdk(),
       buildSystem: TestBuildSystem.all(BuildResult(success: true)),
-      fileSystem: MemoryFileSystem.test(),
-      logger: BufferLogger.test(),
+      fileSystem: fileSystem,
+      logger: logger,
+      processUtils: processUtils,
       osUtils: FakeOperatingSystemUtils(),
     );
     createMinimalMockProjectFiles();
@@ -439,10 +469,12 @@ STDERR STUFF
     ]);
 
     final BuildCommand command = BuildCommand(
+      artifacts: artifacts,
       androidSdk: FakeAndroidSdk(),
       buildSystem: TestBuildSystem.all(BuildResult(success: true)),
       fileSystem: fileSystem,
-      logger: BufferLogger.test(),
+      logger: logger,
+      processUtils: processUtils,
       osUtils: FakeOperatingSystemUtils(),
     );
 
@@ -461,10 +493,12 @@ STDERR STUFF
 
   testUsingContext('macOS build supports build-name and build-number', () async {
     final BuildCommand command = BuildCommand(
+      artifacts: artifacts,
       androidSdk: FakeAndroidSdk(),
       buildSystem: TestBuildSystem.all(BuildResult(success: true)),
-      fileSystem: MemoryFileSystem.test(),
-      logger: BufferLogger.test(),
+      fileSystem: fileSystem,
+      logger: logger,
+      processUtils: processUtils,
       osUtils: FakeOperatingSystemUtils(),
     );
     createMinimalMockProjectFiles();
@@ -496,10 +530,12 @@ STDERR STUFF
 
   testUsingContext('Refuses to build for macOS when feature is disabled', () {
     final CommandRunner<void> runner = createTestCommandRunner(BuildCommand(
+      artifacts: artifacts,
       androidSdk: FakeAndroidSdk(),
       buildSystem: TestBuildSystem.all(BuildResult(success: true)),
-      fileSystem: MemoryFileSystem.test(),
-      logger: BufferLogger.test(),
+      fileSystem: fileSystem,
+      logger: logger,
+      processUtils: processUtils,
       osUtils: FakeOperatingSystemUtils(),
     ));
 
@@ -526,10 +562,12 @@ STDERR STUFF
 
   testUsingContext('Performs code size analysis and sends analytics', () async {
     final BuildCommand command = BuildCommand(
+      artifacts: artifacts,
       androidSdk: FakeAndroidSdk(),
       buildSystem: TestBuildSystem.all(BuildResult(success: true)),
-      fileSystem: MemoryFileSystem.test(),
-      logger: BufferLogger.test(),
+      fileSystem: fileSystem,
+      logger: logger,
+      processUtils: processUtils,
       osUtils: FakeOperatingSystemUtils(),
     );
     createMinimalMockProjectFiles();

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

@@ -4,8 +4,10 @@
 
 import 'package:args/command_runner.dart';
 import 'package:file/memory.dart';
+import 'package:flutter_tools/src/artifacts.dart';
 import 'package:flutter_tools/src/base/file_system.dart';
 import 'package:flutter_tools/src/base/logger.dart';
+import 'package:flutter_tools/src/base/process.dart';
 import 'package:flutter_tools/src/build_system/build_system.dart';
 import 'package:flutter_tools/src/cache.dart';
 import 'package:flutter_tools/src/commands/build.dart';
@@ -28,23 +30,37 @@ void main() {
     ]), throwsToolExit(message: '"--${FlutterOptions.kDartObfuscationOption}" can only be used in '
         'combination with "--${FlutterOptions.kSplitDebugInfoOption}"'));
   });
+
   group('Fatal Logs', () {
     late FakeBuildCommand command;
     late MemoryFileSystem fs;
+    late BufferLogger logger;
+    late ProcessManager processManager;
+    late ProcessUtils processUtils;
+    late Artifacts artifacts;
 
     setUp(() {
       fs = MemoryFileSystem.test();
+      artifacts = Artifacts.test(fileSystem: fs);
       fs.file('/package/pubspec.yaml').createSync(recursive: true);
       fs.currentDirectory = '/package';
       Cache.disableLocking();
+      logger = BufferLogger.test();
+      processManager = FakeProcessManager.empty();
+      processUtils = ProcessUtils(
+        logger: logger,
+        processManager: processManager,
+      );
     });
 
     testUsingContext("doesn't fail if --fatal-warnings specified and no warnings occur", () async {
       command = FakeBuildCommand(
+        artifacts: artifacts,
         androidSdk: FakeAndroidSdk(),
         buildSystem: TestBuildSystem.all(BuildResult(success: true)),
-        fileSystem: MemoryFileSystem.test(),
-        logger: BufferLogger.test(),
+        fileSystem: fs,
+        logger: logger,
+        processUtils: processUtils,
         osUtils: FakeOperatingSystemUtils(),
       );
       try {
@@ -58,15 +74,17 @@ void main() {
       }
     }, overrides: <Type, Generator>{
       FileSystem: () => fs,
-      ProcessManager: () => FakeProcessManager.any(),
+      ProcessManager: () => processManager,
     });
 
     testUsingContext("doesn't fail if --fatal-warnings not specified", () async {
       command = FakeBuildCommand(
+        artifacts: artifacts,
         androidSdk: FakeAndroidSdk(),
         buildSystem: TestBuildSystem.all(BuildResult(success: true)),
-        fileSystem: MemoryFileSystem.test(),
-        logger: BufferLogger.test(),
+        fileSystem: fs,
+        logger: logger,
+        processUtils: processUtils,
         osUtils: FakeOperatingSystemUtils(),
       );
       testLogger.printWarning('Warning: Mild annoyance Will Robinson!');
@@ -80,15 +98,17 @@ void main() {
       }
     }, overrides: <Type, Generator>{
       FileSystem: () => fs,
-      ProcessManager: () => FakeProcessManager.any(),
+      ProcessManager: () => processManager,
     });
 
     testUsingContext('fails if --fatal-warnings specified and warnings emitted', () async {
       command = FakeBuildCommand(
+        artifacts: artifacts,
         androidSdk: FakeAndroidSdk(),
         buildSystem: TestBuildSystem.all(BuildResult(success: true)),
-        fileSystem: MemoryFileSystem.test(),
-        logger: BufferLogger.test(),
+        fileSystem: fs,
+        logger: logger,
+        processUtils: processUtils,
         osUtils: FakeOperatingSystemUtils(),
       );
       testLogger.printWarning('Warning: Mild annoyance Will Robinson!');
@@ -99,15 +119,17 @@ void main() {
       ]), throwsToolExit(message: 'Logger received warning output during the run, and "--${FlutterOptions.kFatalWarnings}" is enabled.'));
     }, overrides: <Type, Generator>{
       FileSystem: () => fs,
-      ProcessManager: () => FakeProcessManager.any(),
+      ProcessManager: () => processManager,
     });
 
     testUsingContext('fails if --fatal-warnings specified and errors emitted', () async {
       command = FakeBuildCommand(
+        artifacts: artifacts,
         androidSdk: FakeAndroidSdk(),
         buildSystem: TestBuildSystem.all(BuildResult(success: true)),
-        fileSystem: MemoryFileSystem.test(),
-        logger: BufferLogger.test(),
+        fileSystem: fs,
+        logger: logger,
+        processUtils: processUtils,
         osUtils: FakeOperatingSystemUtils(),
       );
       testLogger.printError('Error: Danger Will Robinson!');
@@ -118,7 +140,7 @@ void main() {
       ]), throwsToolExit(message: 'Logger received error output during the run, and "--${FlutterOptions.kFatalWarnings}" is enabled.'));
     }, overrides: <Type, Generator>{
       FileSystem: () => fs,
-      ProcessManager: () => FakeProcessManager.any(),
+      ProcessManager: () => processManager,
     });
   });
 }
@@ -149,8 +171,10 @@ class FakeBuildCommand extends BuildCommand {
     required super.osUtils,
     required Logger logger,
     required super.androidSdk,
+    required super.processUtils,
+    required super.artifacts,
     bool verboseHelp = false,
-  }) : super(logger: logger, verboseHelp: verboseHelp,) {
+  }) : super(logger: logger) {
     addSubcommand(FakeBuildSubcommand(logger: logger, verboseHelp: verboseHelp));
   }
 

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

@@ -4,9 +4,11 @@
 
 import 'package:args/command_runner.dart';
 import 'package:file/memory.dart';
+import 'package:flutter_tools/src/artifacts.dart';
 import 'package:flutter_tools/src/base/file_system.dart';
 import 'package:flutter_tools/src/base/logger.dart';
 import 'package:flutter_tools/src/base/platform.dart';
+import 'package:flutter_tools/src/base/process.dart';
 import 'package:flutter_tools/src/build_info.dart';
 import 'package:flutter_tools/src/build_system/build_system.dart';
 import 'package:flutter_tools/src/cache.dart';
@@ -28,6 +30,10 @@ void main() {
       'FLUTTER_ROOT': '/',
     },
   );
+  late ProcessUtils processUtils;
+  late BufferLogger logger;
+  late ProcessManager processManager;
+  late Artifacts artifacts;
 
   setUpAll(() {
     Cache.flutterRoot = '';
@@ -42,15 +48,24 @@ void main() {
     fileSystem.file('.packages').createSync();
     fileSystem.file(fileSystem.path.join('web', 'index.html')).createSync(recursive: true);
     fileSystem.file(fileSystem.path.join('lib', 'main.dart')).createSync(recursive: true);
+    artifacts = Artifacts.test(fileSystem: fileSystem);
+    logger = BufferLogger.test();
+    processManager = FakeProcessManager.empty();
+    processUtils = ProcessUtils(
+      logger: logger,
+      processManager: processManager,
+    );
   });
 
   testUsingContext('Refuses to build for web when missing index.html', () async {
     fileSystem.file(fileSystem.path.join('web', 'index.html')).deleteSync();
     final CommandRunner<void> runner = createTestCommandRunner(BuildCommand(
+      artifacts: artifacts,
       androidSdk: FakeAndroidSdk(),
       buildSystem: TestBuildSystem.all(BuildResult(success: true)),
-      fileSystem: MemoryFileSystem.test(),
-      logger: BufferLogger.test(),
+      fileSystem: fileSystem,
+      logger: logger,
+      processUtils: processUtils,
       osUtils: FakeOperatingSystemUtils(),
     ));
 
@@ -62,15 +77,17 @@ void main() {
     Platform: () => fakePlatform,
     FileSystem: () => fileSystem,
     FeatureFlags: () => TestFeatureFlags(isWebEnabled: true),
-    ProcessManager: () => FakeProcessManager.any(),
+    ProcessManager: () => processManager,
   });
 
   testUsingContext('Refuses to build a debug build for web', () async {
     final CommandRunner<void> runner = createTestCommandRunner(BuildCommand(
+      artifacts: artifacts,
       androidSdk: FakeAndroidSdk(),
       buildSystem: TestBuildSystem.all(BuildResult(success: true)),
       fileSystem: fileSystem,
-      logger: BufferLogger.test(),
+      logger: logger,
+      processUtils: processUtils,
       osUtils: FakeOperatingSystemUtils(),
     ));
 
@@ -79,15 +96,17 @@ void main() {
   }, overrides: <Type, Generator>{
     Platform: () => fakePlatform,
     FeatureFlags: () => TestFeatureFlags(isWebEnabled: true),
-    ProcessManager: () => FakeProcessManager.any(),
+    ProcessManager: () => processManager,
   });
 
   testUsingContext('Refuses to build for web when feature is disabled', () async {
     final CommandRunner<void> runner = createTestCommandRunner(BuildCommand(
+      artifacts: artifacts,
       androidSdk: FakeAndroidSdk(),
       buildSystem: TestBuildSystem.all(BuildResult(success: true)),
       fileSystem: MemoryFileSystem.test(),
-      logger: BufferLogger.test(),
+      logger: logger,
+      processUtils: processUtils,
       osUtils: FakeOperatingSystemUtils(),
     ));
 
@@ -99,15 +118,17 @@ void main() {
     Platform: () => fakePlatform,
     FileSystem: () => fileSystem,
     FeatureFlags: () => TestFeatureFlags(),
-    ProcessManager: () => FakeProcessManager.any(),
+    ProcessManager: () => processManager,
   });
 
   testUsingContext('Setup for a web build with default output directory', () async {
     final BuildCommand buildCommand = BuildCommand(
+      artifacts: artifacts,
       androidSdk: FakeAndroidSdk(),
       buildSystem: TestBuildSystem.all(BuildResult(success: true)),
       fileSystem: fileSystem,
-      logger: BufferLogger.test(),
+      logger: logger,
+      processUtils: processUtils,
       osUtils: FakeOperatingSystemUtils(),
     );
     final CommandRunner<void> runner = createTestCommandRunner(buildCommand);
@@ -121,7 +142,7 @@ void main() {
     Platform: () => fakePlatform,
     FileSystem: () => fileSystem,
     FeatureFlags: () => TestFeatureFlags(isWebEnabled: true),
-    ProcessManager: () => FakeProcessManager.any(),
+    ProcessManager: () => processManager,
     BuildSystem: () => TestBuildSystem.all(BuildResult(success: true), (Target target, Environment environment) {
       expect(environment.defines, <String, String>{
         'TargetFile': 'lib/main.dart',
@@ -144,11 +165,13 @@ void main() {
 
   testUsingContext('Does not allow -O0 optimization level', () async {
     final BuildCommand buildCommand = BuildCommand(
+      artifacts: artifacts,
       androidSdk: FakeAndroidSdk(),
       buildSystem: TestBuildSystem.all(BuildResult(success: true)),
       fileSystem: fileSystem,
       logger: BufferLogger.test(),
       osUtils: FakeOperatingSystemUtils(),
+      processUtils: processUtils,
     );
     final CommandRunner<void> runner = createTestCommandRunner(buildCommand);
     setupFileSystemForEndToEndTest(fileSystem);
@@ -191,10 +214,12 @@ void main() {
   testUsingContext('Setup for a web build with a user specified output directory',
       () async {
     final BuildCommand buildCommand = BuildCommand(
+      artifacts: artifacts,
       androidSdk: FakeAndroidSdk(),
       buildSystem: TestBuildSystem.all(BuildResult(success: true)),
       fileSystem: fileSystem,
-      logger: BufferLogger.test(),
+      logger: logger,
+      processUtils: processUtils,
       osUtils: FakeOperatingSystemUtils(),
     );
     final CommandRunner<void> runner = createTestCommandRunner(buildCommand);
@@ -219,7 +244,7 @@ void main() {
     Platform: () => fakePlatform,
     FileSystem: () => fileSystem,
     FeatureFlags: () => TestFeatureFlags(isWebEnabled: true),
-    ProcessManager: () => FakeProcessManager.any(),
+    ProcessManager: () => processManager,
     BuildSystem: () => TestBuildSystem.all(BuildResult(success: true), (Target target, Environment environment) {
       expect(environment.defines, <String, String>{
         'TargetFile': 'lib/main.dart',
@@ -246,7 +271,7 @@ void main() {
     Platform: () => fakePlatform,
     FileSystem: () => fileSystem,
     FeatureFlags: () => TestFeatureFlags(),
-    ProcessManager: () => FakeProcessManager.any(),
+    ProcessManager: () => processManager,
   });
 
   testUsingContext('not hidden if feature flag is enabled', () async {
@@ -255,7 +280,7 @@ void main() {
     Platform: () => fakePlatform,
     FileSystem: () => fileSystem,
     FeatureFlags: () => TestFeatureFlags(isWebEnabled: true),
-    ProcessManager: () => FakeProcessManager.any(),
+    ProcessManager: () => processManager,
   });
 
   testUsingContext('Defaults to web renderer auto mode when no option is specified', () async {
@@ -270,7 +295,7 @@ void main() {
     Platform: () => fakePlatform,
     FileSystem: () => fileSystem,
     FeatureFlags: () => TestFeatureFlags(isWebEnabled: true),
-    ProcessManager: () => FakeProcessManager.any(),
+    ProcessManager: () => processManager,
     BuildSystem: () => TestBuildSystem.all(BuildResult(success: true)),
   });
 
@@ -295,7 +320,7 @@ void main() {
     Platform: () => fakePlatform,
     FileSystem: () => fileSystem,
     FeatureFlags: () => TestFeatureFlags(isWebEnabled: true),
-    ProcessManager: () => FakeProcessManager.any(),
+    ProcessManager: () => processManager,
     BuildSystem: () => TestBuildSystem.all(BuildResult(success: true)),
   });
 
@@ -311,7 +336,7 @@ void main() {
     Platform: () => fakePlatform,
     FileSystem: () => fileSystem,
     FeatureFlags: () => TestFeatureFlags(isWebEnabled: true),
-    ProcessManager: () => FakeProcessManager.any(),
+    ProcessManager: () => processManager,
     BuildSystem: () => TestBuildSystem.all(BuildResult(success: true)),
   });
 
@@ -327,7 +352,7 @@ void main() {
     Platform: () => fakePlatform,
     FileSystem: () => fileSystem,
     FeatureFlags: () => TestFeatureFlags(isWebEnabled: true),
-    ProcessManager: () => FakeProcessManager.any(),
+    ProcessManager: () => processManager,
     BuildSystem: () => TestBuildSystem.all(BuildResult(success: true)),
   });
 }

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

@@ -82,7 +82,7 @@ void main() {
         '-S',
         fileSystem.path.absolute(fileSystem.path.dirname(buildFilePath)),
         '-B',
-        r'build\windows\x64',
+        r'C:\build\windows\x64',
         '-G',
         generator,
         '-A',
@@ -103,7 +103,7 @@ void main() {
       command: <String>[
         _cmakePath,
         '--build',
-        r'build\windows\x64',
+        r'C:\build\windows\x64',
         '--config',
         buildMode,
         ...<String>['--target', 'INSTALL'],

packages/flutter_tools/test/commands.shard/permeable/build_preview_test.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 'package:args/command_runner.dart';
+import 'package:file_testing/file_testing.dart';
+import 'package:flutter_tools/src/base/file_system.dart';
+import 'package:flutter_tools/src/base/logger.dart';
+import 'package:flutter_tools/src/base/platform.dart';
+import 'package:flutter_tools/src/cache.dart';
+import 'package:flutter_tools/src/commands/build_preview.dart';
+import 'package:flutter_tools/src/globals.dart' as globals;
+
+import '../../src/common.dart';
+import '../../src/context.dart';
+import '../../src/test_flutter_command_runner.dart';
+
+void main() {
+  Cache.disableLocking();
+
+  late Directory tempDir;
+  late BufferLogger logger;
+  final FileSystem fs = LocalFileSystemBlockingSetCurrentDirectory();
+
+  setUp(() {
+    tempDir = fs.systemTempDirectory.createTempSync('flutter_tools_packages_test.');
+    logger = BufferLogger.test();
+  });
+
+  tearDown(() {
+    tryToDelete(tempDir);
+  });
+
+  testUsingContext('flutter build _preview creates preview device', () async {
+    final String projectPath = await createProject(
+      tempDir,
+      arguments: <String>['--no-pub', '--template=app'],
+    );
+    final BuildPreviewCommand command = BuildPreviewCommand(
+      logger: logger,
+      verboseHelp: true,
+      fs: fs,
+      processUtils: globals.processUtils,
+      flutterRoot: Cache.flutterRoot!,
+      artifacts: globals.artifacts!,
+    );
+    final CommandRunner<void> runner = createTestCommandRunner(command);
+    await runner.run(<String>[
+      '_preview',
+      '--no-pub',
+      fs.path.join(projectPath, 'lib', 'main.dart'),
+    ]);
+    expect(
+      fs
+          .directory(Cache.flutterRoot)
+          .childDirectory('bin')
+          .childDirectory('cache')
+          .childDirectory('artifacts')
+          .childDirectory('flutter_preview')
+          .childFile('flutter_preview.exe'),
+      exists,
+    );
+  }, skip: !const LocalPlatform().isWindows); // [intended] Flutter Preview only supported on Windows currently
+}

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

@@ -6,11 +6,13 @@ import 'package:args/command_runner.dart';
 import 'package:file/memory.dart';
 import 'package:flutter_tools/src/android/android_studio.dart';
 import 'package:flutter_tools/src/android/android_workflow.dart';
+import 'package:flutter_tools/src/artifacts.dart';
 import 'package:flutter_tools/src/base/config.dart';
 import 'package:flutter_tools/src/base/file_system.dart';
 import 'package:flutter_tools/src/base/io.dart';
 import 'package:flutter_tools/src/base/logger.dart';
 import 'package:flutter_tools/src/base/platform.dart';
+import 'package:flutter_tools/src/base/process.dart';
 import 'package:flutter_tools/src/base/time.dart';
 import 'package:flutter_tools/src/build_system/build_system.dart';
 import 'package:flutter_tools/src/cache.dart';
@@ -42,6 +44,7 @@ void main() {
     late Directory tempDir;
     late Config testConfig;
     late FileSystem fs;
+
     const String flutterRoot = '/path/to/flutter';
 
     setUp(() {
@@ -161,6 +164,9 @@ void main() {
     late FakeClock fakeClock;
     late FakeDoctor doctor;
     late FakeAndroidStudio androidStudio;
+    late ProcessManager processManager;
+    late BufferLogger logger;
+    late ProcessUtils processUtils;
 
     setUp(() {
       memoryFileSystem = MemoryFileSystem.test();
@@ -169,6 +175,9 @@ void main() {
       fakeClock = FakeClock();
       doctor = FakeDoctor();
       androidStudio = FakeAndroidStudio();
+      processManager = FakeProcessManager.empty();
+      logger = BufferLogger.test();
+      processUtils = ProcessUtils(logger: logger, processManager: processManager);
     });
 
     testUsingContext('flutter commands send timing events', () async {
@@ -220,17 +229,17 @@ void main() {
 
     testUsingContext('compound command usage path', () async {
       final BuildCommand buildCommand = BuildCommand(
+        artifacts: Artifacts.test(fileSystem: memoryFileSystem),
         androidSdk: FakeAndroidSdk(),
         buildSystem: TestBuildSystem.all(BuildResult(success: true)),
-        fileSystem: MemoryFileSystem.test(),
-        logger: BufferLogger.test(),
+        fileSystem: memoryFileSystem,
+        logger: logger,
+        processUtils: processUtils,
         osUtils: FakeOperatingSystemUtils(),
       );
       final FlutterCommand buildApkCommand = buildCommand.subcommands['apk']! as FlutterCommand;
 
       expect(await buildApkCommand.usagePath, 'build/apk');
-    }, overrides: <Type, Generator>{
-      Usage: () => testUsage,
     });
 
     testUsingContext('command sends localtime', () async {
@@ -253,7 +262,7 @@ void main() {
       expect(log.contains(formatDateTime(dateTime)), isTrue);
     }, overrides: <Type, Generator>{
       FileSystem: () => memoryFileSystem,
-      ProcessManager: () => FakeProcessManager.any(),
+      ProcessManager: () => processManager,
       SystemClock: () => fakeClock,
       Platform: () => FakePlatform(
         environment: <String, String>{
@@ -283,7 +292,7 @@ void main() {
       expect(log.contains(formatDateTime(dateTime)), isTrue);
     }, overrides: <Type, Generator>{
       FileSystem: () => memoryFileSystem,
-      ProcessManager: () => FakeProcessManager.any(),
+      ProcessManager: () => processManager,
       SystemClock: () => fakeClock,
       Platform: () => FakePlatform(
         environment: <String, String>{

packages/flutter_tools/test/general.shard/base/os_utils_test.dart

@@ -6,10 +6,10 @@ import 'package:flutter_tools/src/base/file_system.dart';
 import 'package:flutter_tools/src/base/logger.dart';
 import 'package:flutter_tools/src/base/os.dart';
 import 'package:flutter_tools/src/base/platform.dart';
-import 'package:flutter_tools/src/base/signals.dart';
 import 'package:process/process.dart';
 
 import '../../src/common.dart';
+import '../../src/context.dart';
 
 void main() {
   group('OperatingSystemUtils', () {
@@ -17,7 +17,7 @@ void main() {
     late FileSystem fileSystem;
 
     setUp(() {
-      fileSystem = LocalFileSystem.test(signals: Signals.test());
+      fileSystem = LocalFileSystem.test(signals: FakeSignals());
       tempDir = fileSystem.systemTempDirectory.createTempSync('flutter_tools_os_utils_test.');
     });
 

packages/flutter_tools/test/general.shard/commands/build_test.dart

@@ -5,10 +5,12 @@
 import 'package:args/args.dart';
 import 'package:args/command_runner.dart';
 import 'package:file/memory.dart';
+import 'package:flutter_tools/src/artifacts.dart';
 import 'package:flutter_tools/src/base/file_system.dart';
 import 'package:flutter_tools/src/base/io.dart';
 import 'package:flutter_tools/src/base/logger.dart';
 import 'package:flutter_tools/src/base/platform.dart';
+import 'package:flutter_tools/src/base/process.dart';
 import 'package:flutter_tools/src/base/signals.dart';
 import 'package:flutter_tools/src/base/terminal.dart';
 import 'package:flutter_tools/src/build_info.dart';
@@ -111,11 +113,19 @@ void main() {
   });
 
   testUsingContext('Include only supported sub commands', () {
+    final BufferLogger logger = BufferLogger.test();
+    final ProcessUtils processUtils = ProcessUtils(
+      logger: logger,
+      processManager: FakeProcessManager.empty(),
+    );
+    final MemoryFileSystem fs = MemoryFileSystem.test();
     final BuildCommand command = BuildCommand(
+      artifacts: Artifacts.test(fileSystem: fs),
       androidSdk: FakeAndroidSdk(),
       buildSystem: TestBuildSystem.all(BuildResult(success: true)),
-      fileSystem: MemoryFileSystem.test(),
-      logger: BufferLogger.test(),
+      fileSystem: fs,
+      logger: logger,
+      processUtils: processUtils,
       osUtils: FakeOperatingSystemUtils(),
     );
     for (final Command<void> x in command.subcommands.values) {

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

@@ -6,6 +6,7 @@ import 'dart:async';
 
 import 'package:file/memory.dart';
 import 'package:flutter_tools/src/application_package.dart';
+import 'package:flutter_tools/src/artifacts.dart';
 import 'package:flutter_tools/src/base/file_system.dart';
 import 'package:flutter_tools/src/base/logger.dart';
 import 'package:flutter_tools/src/base/platform.dart';
@@ -22,20 +23,38 @@ import 'package:test/fake.dart';
 
 import '../src/common.dart';
 import '../src/context.dart';
+import '../src/fakes.dart';
 
 void main() {
+  String? flutterRootBackup;
+  late MemoryFileSystem fs;
+  late File previewBinary;
+
+  setUp(() {
+    fs = MemoryFileSystem.test(style: FileSystemStyle.windows);
+    Cache.flutterRoot = r'C:\path\to\flutter';
+    previewBinary = fs.file('${Cache.flutterRoot}\\bin\\cache\\artifacts\\flutter_preview\\flutter_preview.exe');
+    previewBinary.createSync(recursive: true);
+    flutterRootBackup = Cache.flutterRoot;
+  });
+
+  tearDown(() {
+    Cache.flutterRoot = flutterRootBackup;
+  });
+
   testWithoutContext('PreviewDevice defaults', () async {
     final PreviewDevice device = PreviewDevice(
-      fileSystem: MemoryFileSystem.test(),
+      artifacts: Artifacts.test(),
+      fileSystem: fs,
       processManager: FakeProcessManager.any(),
+      previewBinary: previewBinary,
       logger: BufferLogger.test(),
-      platform: FakePlatform(),
     );
 
     expect(await device.isLocalEmulator, false);
     expect(device.name, 'preview');
     expect(await device.sdkNameAndVersion, 'preview');
-    expect(await device.targetPlatform, TargetPlatform.tester);
+    expect(await device.targetPlatform, TargetPlatform.windows_x64);
     expect(device.category, Category.desktop);
     expect(device.ephemeral, false);
     expect(device.id, 'preview');
@@ -48,29 +67,29 @@ void main() {
   });
 
   testUsingContext('Can build a simulator app', () async {
-    Cache.flutterRoot = '';
     final Completer<void> completer = Completer<void>();
-    final FileSystem fileSystem = MemoryFileSystem.test();
     final BufferLogger logger = BufferLogger.test();
     final PreviewDevice device = PreviewDevice(
-      fileSystem: fileSystem,
+      artifacts: Artifacts.test(),
+      fileSystem: fs,
+      previewBinary: previewBinary,
       processManager: FakeProcessManager.list(<FakeCommand>[
         FakeCommand(
           command: const <String>[
-            '/.tmp_rand0/flutter_preview.rand0/splash',
+            r'C:\.tmp_rand0\flutter_preview.rand0\flutter_preview.exe',
           ],
           stdout: 'The Dart VM service is listening on http://127.0.0.1:64494/fZ_B2N6JRwY=/\n',
           completer: completer,
         ),
       ]),
       logger: logger,
-      platform: FakePlatform(),
-      builderFactory: () => FakeBundleBuilder(fileSystem),
+      builderFactory: () => FakeBundleBuilder(fs),
     );
-    fileSystem
-      .directory('artifacts_temp')
-      .childDirectory('Debug')
-      .createSync(recursive: true);
+    final Directory previewDeviceCacheDir = fs
+      .directory('Artifact.windowsDesktopPath.TargetPlatform.windows_x64.debug')
+      ..createSync(recursive: true);
+    previewDeviceCacheDir.childFile('flutter_windows.dll').writeAsStringSync('1010101');
+    previewDeviceCacheDir.childFile('icudtl.dat').writeAsStringSync('1010101');
 
     final LaunchResult result = await device.startApp(
       FakeApplicationPackage(),
@@ -80,6 +99,84 @@ void main() {
     expect(result.started, true);
     expect(result.vmServiceUri, Uri.parse('http://127.0.0.1:64494/fZ_B2N6JRwY=/'));
   });
+
+  group('PreviewDeviceDiscovery', () {
+    late Artifacts artifacts;
+    late ProcessManager processManager;
+    final FakePlatform windowsPlatform = FakePlatform(operatingSystem: 'windows');
+    final FakePlatform macPlatform = FakePlatform(operatingSystem: 'macos');
+    final FakePlatform linuxPlatform = FakePlatform();
+    final TestFeatureFlags featureFlags = TestFeatureFlags(isPreviewDeviceEnabled: true);
+
+    setUp(() {
+      artifacts = Artifacts.test(fileSystem: fs);
+      processManager = FakeProcessManager.empty();
+    });
+
+    testWithoutContext('PreviewDeviceDiscovery on linux', () async {
+      final PreviewDeviceDiscovery discovery = PreviewDeviceDiscovery(
+        artifacts: artifacts,
+        fileSystem: fs,
+        logger: BufferLogger.test(),
+        processManager: processManager,
+        platform: linuxPlatform,
+        featureFlags: featureFlags,
+      );
+
+      final List<Device> devices = await discovery.devices();
+
+      expect(devices, isEmpty);
+    });
+
+    testWithoutContext('PreviewDeviceDiscovery on macOS', () async {
+      final PreviewDeviceDiscovery discovery = PreviewDeviceDiscovery(
+        artifacts: artifacts,
+        fileSystem: fs,
+        logger: BufferLogger.test(),
+        processManager: processManager,
+        platform: macPlatform,
+        featureFlags: featureFlags,
+      );
+
+      final List<Device> devices = await discovery.devices();
+
+      expect(devices, isEmpty);
+    });
+
+    testWithoutContext('PreviewDeviceDiscovery on Windows returns preview when binary exists', () async {
+      // ensure Flutter preview binary exists in cache.
+      fs.file(artifacts.getArtifactPath(Artifact.flutterPreviewDevice)).writeAsBytesSync(<int>[1, 0, 0, 1]);
+      final PreviewDeviceDiscovery discovery = PreviewDeviceDiscovery(
+        artifacts: artifacts,
+        fileSystem: fs,
+        logger: BufferLogger.test(),
+        processManager: processManager,
+        platform: windowsPlatform,
+        featureFlags: featureFlags,
+      );
+
+      final List<Device> devices = await discovery.devices();
+
+      expect(devices, hasLength(1));
+      final Device previewDevice = devices.first;
+      expect(previewDevice, isA<PreviewDevice>());
+    });
+
+    testWithoutContext('PreviewDeviceDiscovery on Windows returns nothing when binary does not exist', () async {
+      final PreviewDeviceDiscovery discovery = PreviewDeviceDiscovery(
+        artifacts: artifacts,
+        fileSystem: fs,
+        logger: BufferLogger.test(),
+        processManager: processManager,
+        platform: windowsPlatform,
+        featureFlags: featureFlags,
+      );
+
+      final List<Device> devices = await discovery.devices();
+
+      expect(devices, isEmpty);
+    });
+  });
 }
 
 class FakeFlutterProject extends Fake implements FlutterProject { }

packages/flutter_tools/test/general.shard/web/migrations/scrub_generated_plugin_registrant_test.dart

@@ -3,8 +3,10 @@
 // found in the LICENSE file.
 
 import 'package:file/memory.dart';
+import 'package:flutter_tools/src/artifacts.dart';
 import 'package:flutter_tools/src/base/file_system.dart';
 import 'package:flutter_tools/src/base/logger.dart';
+import 'package:flutter_tools/src/base/process.dart';
 import 'package:flutter_tools/src/build_system/build_system.dart';
 import 'package:flutter_tools/src/cache.dart';
 import 'package:flutter_tools/src/commands/build.dart';
@@ -26,14 +28,24 @@ void main() {
     late File registrant;
 
     // Environment overrides
+    late Artifacts artifacts;
     late FileSystem fileSystem;
     late ProcessManager processManager;
     late BuildSystem buildSystem;
+    late ProcessUtils processUtils;
+    late BufferLogger logger;
 
     setUp(() {
       // Prepare environment overrides
       fileSystem = MemoryFileSystem.test();
+      artifacts = Artifacts.test(fileSystem: fileSystem);
       processManager = FakeProcessManager.any();
+      logger = BufferLogger.test();
+      processUtils = ProcessUtils(
+        processManager: processManager,
+        logger: logger,
+      );
+
       buildSystem = TestBuildSystem.all(BuildResult(success: true));
       // Write some initial state into our testing filesystem
       setupFileSystemForEndToEndTest(fileSystem);
@@ -47,11 +59,13 @@ void main() {
       expect(registrant.existsSync(), isFalse);
 
       await createTestCommandRunner(BuildCommand(
+        artifacts: artifacts,
         androidSdk: FakeAndroidSdk(),
         buildSystem: buildSystem,
         fileSystem: fileSystem,
         logger: BufferLogger.test(),
         osUtils: FakeOperatingSystemUtils(),
+        processUtils: processUtils,
       ))
           .run(<String>['build', 'web', '--no-pub']);
 
@@ -70,11 +84,13 @@ void main() {
       expect(contentsBeforeBuild, isNot(contains('lib/generated_plugin_registrant.dart')));
 
       await createTestCommandRunner(BuildCommand(
+        artifacts: artifacts,
         androidSdk: FakeAndroidSdk(),
         buildSystem: buildSystem,
         fileSystem: fileSystem,
-        logger: BufferLogger.test(),
+        logger: logger,
         osUtils: FakeOperatingSystemUtils(),
+        processUtils: processUtils,
       ))
           .run(<String>['build', 'web', '--no-pub']);
 
@@ -92,10 +108,12 @@ void main() {
       expect(gitignore.readAsStringSync(), contains('lib/generated_plugin_registrant.dart'));
 
       await createTestCommandRunner(BuildCommand(
+        artifacts: artifacts,
         androidSdk: FakeAndroidSdk(),
         buildSystem: buildSystem,
         fileSystem: fileSystem,
-        logger: BufferLogger.test(),
+        logger: logger,
+        processUtils: processUtils,
         osUtils: FakeOperatingSystemUtils(),
       ))
           .run(<String>['build', 'web', '--no-pub']);
@@ -113,10 +131,12 @@ void main() {
       expect(registrant.existsSync(), isTrue);
 
       await createTestCommandRunner(BuildCommand(
+        artifacts: artifacts,
         androidSdk: FakeAndroidSdk(),
         buildSystem: buildSystem,
         fileSystem: fileSystem,
-        logger: BufferLogger.test(),
+        logger: logger,
+        processUtils: processUtils,
         osUtils: FakeOperatingSystemUtils(),
       ))
           .run(<String>['build', 'web', '--no-pub']);
@@ -136,10 +156,12 @@ void main() {
       expect(gitignore.readAsStringSync(), contains('lib/generated_plugin_registrant.dart'));
 
       await createTestCommandRunner(BuildCommand(
+        artifacts: artifacts,
         androidSdk: FakeAndroidSdk(),
         buildSystem: buildSystem,
         fileSystem: fileSystem,
-        logger: BufferLogger.test(),
+        logger: logger,
+        processUtils: processUtils,
         osUtils: FakeOperatingSystemUtils(),
       ))
           .run(<String>['build', 'web', '--no-pub']);

packages/flutter_tools/test/src/context.dart

@@ -382,7 +382,8 @@ class NoopCrashReporter implements CrashReporter {
 }
 
 class LocalFileSystemBlockingSetCurrentDirectory extends LocalFileSystem {
-  // Use [FakeSignals] so developers running the test suite can kill the test runner.
+  // Use [FakeSignals] so developers running the test suite can kill the test
+  // runner.
   LocalFileSystemBlockingSetCurrentDirectory() : super.test(signals: FakeSignals());
 
   @override

packages/flutter_tools/test/src/fakes.dart

@@ -462,6 +462,7 @@ class TestFeatureFlags implements FeatureFlags {
     this.isFlutterWebWasmEnabled = false,
     this.isCliAnimationEnabled = true,
     this.isNativeAssetsEnabled = false,
+    this.isPreviewDeviceEnabled = false,
   });
 
   @override
@@ -497,31 +498,24 @@ class TestFeatureFlags implements FeatureFlags {
   @override
   final bool isNativeAssetsEnabled;
 
+  @override
+  final bool isPreviewDeviceEnabled;
+
   @override
   bool isEnabled(Feature feature) {
-    switch (feature) {
-      case flutterWebFeature:
-        return isWebEnabled;
-      case flutterLinuxDesktopFeature:
-        return isLinuxEnabled;
-      case flutterMacOSDesktopFeature:
-        return isMacOSEnabled;
-      case flutterWindowsDesktopFeature:
-        return isWindowsEnabled;
-      case flutterAndroidFeature:
-        return isAndroidEnabled;
-      case flutterIOSFeature:
-        return isIOSEnabled;
-      case flutterFuchsiaFeature:
-        return isFuchsiaEnabled;
-      case flutterCustomDevicesFeature:
-        return areCustomDevicesEnabled;
-      case cliAnimation:
-        return isCliAnimationEnabled;
-      case nativeAssets:
-        return isNativeAssetsEnabled;
-    }
-    return false;
+    return switch (feature) {
+      flutterWebFeature => isWebEnabled,
+      flutterLinuxDesktopFeature => isLinuxEnabled,
+      flutterMacOSDesktopFeature => isMacOSEnabled,
+      flutterWindowsDesktopFeature => isWindowsEnabled,
+      flutterAndroidFeature => isAndroidEnabled,
+      flutterIOSFeature => isIOSEnabled,
+      flutterFuchsiaFeature => isFuchsiaEnabled,
+      flutterCustomDevicesFeature => areCustomDevicesEnabled,
+      cliAnimation => isCliAnimationEnabled,
+      nativeAssets => isNativeAssetsEnabled,
+      _ => false,
+    };
   }
 }