packages/flutter_tools/lib/src/isolated/resident_web_runner.dart

// Copyright 2014 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import 'dart:async';

import 'package:dwds/dwds.dart';
import 'package:package_config/package_config.dart';
import 'package:unified_analytics/unified_analytics.dart';
import 'package:vm_service/vm_service.dart' as vmservice;
import 'package:webkit_inspection_protocol/webkit_inspection_protocol.dart'
    hide StackTrace;

import '../application_package.dart';
import '../base/async_guard.dart';
import '../base/common.dart';
import '../base/file_system.dart';
import '../base/io.dart';
import '../base/logger.dart';
import '../base/net.dart';
import '../base/terminal.dart';
import '../base/time.dart';
import '../base/utils.dart';
import '../build_info.dart';
import '../cache.dart';
import '../dart/language_version.dart';
import '../devfs.dart';
import '../device.dart';
import '../flutter_plugins.dart';
import '../globals.dart' as globals;
import '../project.dart';
import '../reporting/reporting.dart';
import '../resident_devtools_handler.dart';
import '../resident_runner.dart';
import '../run_hot.dart';
import '../vmservice.dart';
import '../web/chrome.dart';
import '../web/compile.dart';
import '../web/file_generators/flutter_service_worker_js.dart';
import '../web/file_generators/main_dart.dart' as main_dart;
import '../web/web_device.dart';
import '../web/web_runner.dart';
import 'devfs_web.dart';

/// Injectable factory to create a [ResidentWebRunner].
class DwdsWebRunnerFactory extends WebRunnerFactory {
  @override
  ResidentRunner createWebRunner(
    FlutterDevice device, {
    String? target,
    required bool stayResident,
    required FlutterProject flutterProject,
    required bool? ipv6,
    required DebuggingOptions debuggingOptions,
    UrlTunneller? urlTunneller,
    required Logger logger,
    required FileSystem fileSystem,
    required SystemClock systemClock,
    required Usage usage,
    required Analytics analytics,
    bool machine = false,
  }) {
    return ResidentWebRunner(
      device,
      target: target,
      flutterProject: flutterProject,
      debuggingOptions: debuggingOptions,
      ipv6: ipv6,
      stayResident: stayResident,
      urlTunneller: urlTunneller,
      machine: machine,
      usage: usage,
      analytics: analytics,
      systemClock: systemClock,
      fileSystem: fileSystem,
      logger: logger,
    );
  }
}

const String kExitMessage = 'Failed to establish connection with the application '
  'instance in Chrome.\nThis can happen if the websocket connection used by the '
  'web tooling is unable to correctly establish a connection, for example due to a firewall.';

class ResidentWebRunner extends ResidentRunner {
  ResidentWebRunner(
    FlutterDevice device, {
    String? target,
    bool stayResident = true,
    bool machine = false,
    required this.flutterProject,
    required bool? ipv6,
    required DebuggingOptions debuggingOptions,
    required FileSystem fileSystem,
    required Logger logger,
    required SystemClock systemClock,
    required Usage usage,
    required Analytics analytics,
    UrlTunneller? urlTunneller,
    ResidentDevtoolsHandlerFactory devtoolsHandler = createDefaultHandler,
  }) : _fileSystem = fileSystem,
       _logger = logger,
       _systemClock = systemClock,
       _usage = usage,
       _analytics = analytics,
       _urlTunneller = urlTunneller,
       super(
          <FlutterDevice>[device],
          target: target ?? fileSystem.path.join('lib', 'main.dart'),
          debuggingOptions: debuggingOptions,
          ipv6: ipv6,
          stayResident: stayResident,
          machine: machine,
          devtoolsHandler: devtoolsHandler,
        );

  final FileSystem _fileSystem;
  final Logger _logger;
  final SystemClock _systemClock;
  final Usage _usage;
  final Analytics _analytics;
  final UrlTunneller? _urlTunneller;

  @override
  Logger get logger => _logger;

  @override
  FileSystem get fileSystem => _fileSystem;

  FlutterDevice? get device => flutterDevices.first;
  final FlutterProject flutterProject;

  // Used with the new compiler to generate a bootstrap file containing plugins
  // and platform initialization.
  Directory? _generatedEntrypointDirectory;

  // Only non-wasm debug builds of the web support the service protocol.
  @override
  bool get supportsServiceProtocol => !debuggingOptions.webUseWasm && isRunningDebug && deviceIsDebuggable;

  @override
  bool get debuggingEnabled => isRunningDebug && deviceIsDebuggable;

  /// WebServer device is debuggable when running with --start-paused.
  bool get deviceIsDebuggable => device!.device is! WebServerDevice || debuggingOptions.startPaused;

  @override
  bool get supportsWriteSkSL => false;

  @override
  // Web uses a different plugin registry.
  bool get generateDartPluginRegistry => false;

  bool get _enableDwds => debuggingEnabled;

  ConnectionResult? _connectionResult;
  StreamSubscription<vmservice.Event>? _stdOutSub;
  StreamSubscription<vmservice.Event>? _stdErrSub;
  StreamSubscription<vmservice.Event>? _extensionEventSub;
  bool _exited = false;
  WipConnection? _wipConnection;
  ChromiumLauncher? _chromiumLauncher;

  FlutterVmService get _vmService {
    if (_instance != null) {
      return _instance!;
    }
    final vmservice.VmService? service = _connectionResult?.vmService;
    final Uri websocketUri = Uri.parse(_connectionResult!.debugConnection!.uri);
    final Uri httpUri = _httpUriFromWebsocketUri(websocketUri);
    return _instance ??= FlutterVmService(service!, wsAddress: websocketUri, httpAddress: httpUri);
  }

  FlutterVmService? _instance;

  @override
  Future<void> cleanupAfterSignal() async {
    await _cleanup();
  }

  @override
  Future<void> cleanupAtFinish() async {
    await _cleanup();
  }

  Future<void> _cleanup() async {
    if (_exited) {
      return;
    }
    await residentDevtoolsHandler!.shutdown();
    await _stdOutSub?.cancel();
    await _stdErrSub?.cancel();
    await _extensionEventSub?.cancel();
    await device!.device!.stopApp(null);
    try {
      _generatedEntrypointDirectory?.deleteSync(recursive: true);
    } on FileSystemException {
      // Best effort to clean up temp dirs.
      _logger.printTrace(
        'Failed to clean up temp directory: ${_generatedEntrypointDirectory!.path}',
      );
    }
    _exited = true;
  }

  Future<void> _cleanupAndExit() async {
    await _cleanup();
    appFinished();
  }

  @override
  void printHelp({bool details = true}) {
    if (details) {
      return printHelpDetails();
    }
    const String fire = '🔥';
    const String rawMessage =
        '  To hot restart changes while running, press "r" or "R".';
    final String message = _logger.terminal.color(
      fire + _logger.terminal.bolden(rawMessage),
      TerminalColor.red,
    );
    _logger.printStatus(message);
    const String quitMessage = 'To quit, press "q".';
    _logger.printStatus('For a more detailed help message, press "h". $quitMessage');
    _logger.printStatus('');
    printDebuggerList();
  }

  @override
  Future<void> stopEchoingDeviceLog() async {
    // Do nothing for ResidentWebRunner
    await device!.stopEchoingDeviceLog();
  }

  @override
  Future<int> run({
    Completer<DebugConnectionInfo>? connectionInfoCompleter,
    Completer<void>? appStartedCompleter,
    bool enableDevTools = false, // ignored, we don't yet support devtools for web
    String? route,
  }) async {
    final ApplicationPackage? package = await ApplicationPackageFactory.instance!.getPackageForPlatform(
      TargetPlatform.web_javascript,
      buildInfo: debuggingOptions.buildInfo,
    );
    if (package == null) {
      _logger.printStatus('This application is not configured to build on the web.');
      _logger.printStatus('To add web support to a project, run `flutter create .`.');
    }
    final String modeName = debuggingOptions.buildInfo.friendlyModeName;
    _logger.printStatus(
      'Launching ${getDisplayPath(target, _fileSystem)} '
      'on ${device!.device!.name} in $modeName mode...',
    );
    if (device!.device is ChromiumDevice) {
      _chromiumLauncher = (device!.device! as ChromiumDevice).chromeLauncher;
    }

    try {
      return await asyncGuard(() async {
        Future<int> getPort() async {
          if (debuggingOptions.port == null) {
            return globals.os.findFreePort();
          }

          final int? port = int.tryParse(debuggingOptions.port ?? '');

          if (port == null) {
            logger.printError('''
Received a non-integer value for port: ${debuggingOptions.port}
A randomly-chosen available port will be used instead.
''');
            return globals.os.findFreePort();
          }

          if (port < 0 || port > 65535) {
            throwToolExit('''
Invalid port: ${debuggingOptions.port}
Please provide a valid TCP port (an integer between 0 and 65535, inclusive).
    ''');
          }

          return port;
        }

        final ExpressionCompiler? expressionCompiler =
          debuggingOptions.webEnableExpressionEvaluation
              ? WebExpressionCompiler(device!.generator!, fileSystem: _fileSystem)
              : null;

        device!.devFS = WebDevFS(
          hostname: debuggingOptions.hostname ?? 'localhost',
          port: await getPort(),
          tlsCertPath: debuggingOptions.tlsCertPath,
          tlsCertKeyPath: debuggingOptions.tlsCertKeyPath,
          packagesFilePath: packagesFilePath,
          urlTunneller: _urlTunneller,
          useSseForDebugProxy: debuggingOptions.webUseSseForDebugProxy,
          useSseForDebugBackend: debuggingOptions.webUseSseForDebugBackend,
          useSseForInjectedClient: debuggingOptions.webUseSseForInjectedClient,
          buildInfo: debuggingOptions.buildInfo,
          enableDwds: _enableDwds,
          enableDds: debuggingOptions.enableDds,
          entrypoint: _fileSystem.file(target).uri,
          expressionCompiler: expressionCompiler,
          extraHeaders: debuggingOptions.webHeaders,
          chromiumLauncher: _chromiumLauncher,
          nullAssertions: debuggingOptions.nullAssertions,
          nullSafetyMode: debuggingOptions.buildInfo.nullSafetyMode,
          nativeNullAssertions: debuggingOptions.nativeNullAssertions,
          ddcModuleSystem: debuggingOptions.buildInfo.ddcModuleFormat == DdcModuleFormat.ddc,
          webRenderer: debuggingOptions.webRenderer,
          isWasm: debuggingOptions.webUseWasm,
          rootDirectory: fileSystem.directory(projectRootPath),
        );
        Uri url = await device!.devFS!.create();
        if (debuggingOptions.tlsCertKeyPath != null && debuggingOptions.tlsCertPath != null) {
          url = url.replace(scheme: 'https');
        }
        if (debuggingOptions.buildInfo.isDebug && !debuggingOptions.webUseWasm) {
          await runSourceGenerators();
          final UpdateFSReport report = await _updateDevFS(fullRestart: true);
          if (!report.success) {
            _logger.printError('Failed to compile application.');
            appFailedToStart();
            return 1;
          }
          device!.generator!.accept();
          cacheInitialDillCompilation();
        } else {
          final WebBuilder webBuilder = WebBuilder(
            logger: _logger,
            processManager: globals.processManager,
            buildSystem: globals.buildSystem,
            fileSystem: _fileSystem,
            flutterVersion: globals.flutterVersion,
            usage: globals.flutterUsage,
            analytics: globals.analytics,
          );
          await webBuilder.buildWeb(
            flutterProject,
            target,
            debuggingOptions.buildInfo,
            ServiceWorkerStrategy.none,
            compilerConfigs: <WebCompilerConfig>[_compilerConfig],
          );
        }
        await device!.device!.startApp(
          package,
          mainPath: target,
          debuggingOptions: debuggingOptions,
          platformArgs: <String, Object>{
             'uri': url.toString(),
          },
        );
        return attach(
          connectionInfoCompleter: connectionInfoCompleter,
          appStartedCompleter: appStartedCompleter,
          enableDevTools: enableDevTools,
        );
      });
    } on WebSocketException catch (error, stackTrace) {
      appFailedToStart();
      _logger.printError('$error', stackTrace: stackTrace);
      throwToolExit(kExitMessage);
    } on ChromeDebugException catch (error, stackTrace) {
      appFailedToStart();
      _logger.printError('$error', stackTrace: stackTrace);
      throwToolExit(kExitMessage);
    } on AppConnectionException catch (error, stackTrace) {
      appFailedToStart();
      _logger.printError('$error', stackTrace: stackTrace);
      throwToolExit(kExitMessage);
    } on SocketException catch (error, stackTrace) {
      appFailedToStart();
      _logger.printError('$error', stackTrace: stackTrace);
      throwToolExit(kExitMessage);
    } on Exception {
      appFailedToStart();
      rethrow;
    }
  }

  WebCompilerConfig get _compilerConfig => (debuggingOptions.webUseWasm)
    ? WasmCompilerConfig(
        optimizationLevel: 0,
        stripWasm: false,
        renderer: debuggingOptions.webRenderer
      )
    : JsCompilerConfig.run(
        nativeNullAssertions: debuggingOptions.nativeNullAssertions,
        renderer: debuggingOptions.webRenderer,
      );

  @override
  Future<OperationResult> restart({
    bool fullRestart = false,
    bool? pause = false,
    String? reason,
    bool benchmarkMode = false,
  }) async {
    final DateTime start = _systemClock.now();
    final Status status = _logger.startProgress(
      'Performing hot restart...',
      progressId: 'hot.restart',
    );

    if (debuggingOptions.buildInfo.isDebug && !debuggingOptions.webUseWasm) {
      await runSourceGenerators();
      // Full restart is always false for web, since the extra recompile is wasteful.
      final UpdateFSReport report = await _updateDevFS();
      if (report.success) {
        device!.generator!.accept();
      } else {
        status.stop();
        await device!.generator!.reject();
        return OperationResult(1, 'Failed to recompile application.');
      }
    } else {
      try {
        final WebBuilder webBuilder = WebBuilder(
          logger: _logger,
          processManager: globals.processManager,
          buildSystem: globals.buildSystem,
          fileSystem: _fileSystem,
          flutterVersion: globals.flutterVersion,
          usage: globals.flutterUsage,
          analytics: globals.analytics,
        );
        await webBuilder.buildWeb(
          flutterProject,
          target,
          debuggingOptions.buildInfo,
          ServiceWorkerStrategy.none,
          compilerConfigs: <WebCompilerConfig>[_compilerConfig],
        );
      } on ToolExit {
        return OperationResult(1, 'Failed to recompile application.');
      }
    }

    try {
      if (!deviceIsDebuggable) {
        _logger.printStatus('Recompile complete. Page requires refresh.');
      } else if (isRunningDebug) {
        await _vmService.service.callMethod('hotRestart');
      } else {
        // On non-debug builds, a hard refresh is required to ensure the
        // up to date sources are loaded.
        await _wipConnection?.sendCommand('Page.reload', <String, Object>{
          'ignoreCache': !debuggingOptions.buildInfo.isDebug,
        });
      }
    } on Exception catch (err) {
      return OperationResult(1, err.toString(), fatal: true);
    } finally {
      status.stop();
    }

    final Duration elapsed = _systemClock.now().difference(start);
    final String elapsedMS = getElapsedAsMilliseconds(elapsed);
    _logger.printStatus('Restarted application in $elapsedMS.');
    unawaited(residentDevtoolsHandler!.hotRestart(flutterDevices));

    // Don't track restart times for dart2js builds or web-server devices.
    if (debuggingOptions.buildInfo.isDebug && deviceIsDebuggable) {
      _usage.sendTiming('hot', 'web-incremental-restart', elapsed);
      _analytics.send(Event.timing(
        workflow: 'hot',
        variableName: 'web-incremental-restart',
        elapsedMilliseconds: elapsed.inMilliseconds,
      ));
      final String sdkName = await device!.device!.sdkNameAndVersion;
      HotEvent(
        'restart',
        targetPlatform: getNameForTargetPlatform(TargetPlatform.web_javascript),
        sdkName: sdkName,
        emulator: false,
        fullRestart: true,
        reason: reason,
        overallTimeInMs: elapsed.inMilliseconds,
      ).send();
      _analytics.send(Event.hotRunnerInfo(
        label: 'restart',
        targetPlatform: getNameForTargetPlatform(TargetPlatform.web_javascript),
        sdkName: sdkName,
        emulator: false,
        fullRestart: true,
        reason: reason,
        overallTimeInMs: elapsed.inMilliseconds
      ));
    }
    return OperationResult.ok;
  }

  // Flutter web projects need to include a generated main entrypoint to call the
  // appropriate bootstrap method and inject plugins.
  // Keep this in sync with build_system/targets/web.dart.
  Future<Uri> _generateEntrypoint(Uri mainUri, PackageConfig? packageConfig) async {
    File? result = _generatedEntrypointDirectory?.childFile('web_entrypoint.dart');
    if (_generatedEntrypointDirectory == null) {
      _generatedEntrypointDirectory ??= _fileSystem.systemTempDirectory.createTempSync('flutter_tools.')
        ..createSync();
      result = _generatedEntrypointDirectory!.childFile('web_entrypoint.dart');

      // Generates the generated_plugin_registrar
      await injectBuildTimePluginFiles(flutterProject, webPlatform: true, destination: _generatedEntrypointDirectory!);
      // The below works because `injectBuildTimePluginFiles` is configured to write
      // the web_plugin_registrant.dart file alongside the generated main.dart
      const String generatedImport = 'web_plugin_registrant.dart';

      Uri? importedEntrypoint = packageConfig!.toPackageUri(mainUri);
      // Special handling for entrypoints that are not under lib, such as test scripts.
      if (importedEntrypoint == null) {
        final String parent = _fileSystem.file(mainUri).parent.path;
        flutterDevices.first.generator!
          ..addFileSystemRoot(parent)
          ..addFileSystemRoot(_fileSystem.directory('test').absolute.path);
        importedEntrypoint = Uri(
          scheme: 'org-dartlang-app',
          path: '/${mainUri.pathSegments.last}',
        );
      }
      final LanguageVersion languageVersion = determineLanguageVersion(
        _fileSystem.file(mainUri),
        packageConfig[flutterProject.manifest.appName],
        Cache.flutterRoot!,
      );

      final String entrypoint = main_dart.generateMainDartFile(importedEntrypoint.toString(),
        languageVersion: languageVersion,
        pluginRegistrantEntrypoint: generatedImport,
      );

      result.writeAsStringSync(entrypoint);
    }
    return result!.absolute.uri;
  }

  Future<UpdateFSReport> _updateDevFS({bool fullRestart = false}) async {
    final bool isFirstUpload = !assetBundle.wasBuiltOnce();
    final bool rebuildBundle = assetBundle.needsBuild();
    if (rebuildBundle) {
      _logger.printTrace('Updating assets');
      final int result = await assetBundle.build(
        packagesPath: debuggingOptions.buildInfo.packagesPath,
        targetPlatform: TargetPlatform.web_javascript,
      );
      if (result != 0) {
        return UpdateFSReport();
      }
    }
    final InvalidationResult invalidationResult = await projectFileInvalidator.findInvalidated(
      lastCompiled: device!.devFS!.lastCompiled,
      urisToMonitor: device!.devFS!.sources,
      packagesPath: packagesFilePath,
      packageConfig: device!.devFS!.lastPackageConfig
        ?? debuggingOptions.buildInfo.packageConfig,
    );
    final Status devFSStatus = _logger.startProgress(
      'Waiting for connection from debug service on ${device!.device!.name}...',
    );
    final UpdateFSReport report = await device!.devFS!.update(
      mainUri: await _generateEntrypoint(
        _fileSystem.file(mainPath).absolute.uri,
        invalidationResult.packageConfig,
      ),
      target: target,
      bundle: assetBundle,
      bundleFirstUpload: isFirstUpload,
      generator: device!.generator!,
      fullRestart: fullRestart,
      dillOutputPath: dillOutputPath,
      pathToReload: getReloadPath(fullRestart: fullRestart, swap: false),
      invalidatedFiles: invalidationResult.uris!,
      packageConfig: invalidationResult.packageConfig!,
      trackWidgetCreation: debuggingOptions.buildInfo.trackWidgetCreation,
      shaderCompiler: device!.developmentShaderCompiler,
    );
    devFSStatus.stop();
    _logger.printTrace('Synced ${getSizeAsPlatformMB(report.syncedBytes)}.');
    return report;
  }

  @override
  Future<int> attach({
    Completer<DebugConnectionInfo>? connectionInfoCompleter,
    Completer<void>? appStartedCompleter,
    bool allowExistingDdsInstance = false,
    bool enableDevTools = false, // ignored, we don't yet support devtools for web
    bool needsFullRestart = true,
  }) async {
    if (_chromiumLauncher != null) {
      final Chromium chrome = await _chromiumLauncher!.connectedInstance;
      final ChromeTab? chromeTab = await chrome.chromeConnection.getTab((ChromeTab chromeTab) {
        return !chromeTab.url.startsWith('chrome-extension');
      }, retryFor: const Duration(seconds: 5));
      if (chromeTab == null) {
        throwToolExit('Failed to connect to Chrome instance.');
      }
      _wipConnection = await chromeTab.connect();
    }
    Uri? websocketUri;
    if (supportsServiceProtocol) {
      final WebDevFS webDevFS = device!.devFS! as WebDevFS;
      final bool useDebugExtension = device!.device is WebServerDevice && debuggingOptions.startPaused;
      _connectionResult = await webDevFS.connect(useDebugExtension);
      unawaited(_connectionResult!.debugConnection!.onDone.whenComplete(_cleanupAndExit));

      void onLogEvent(vmservice.Event event) {
        final String message = processVmServiceMessage(event);
        _logger.printStatus(message);
      }

      _stdOutSub = _vmService.service.onStdoutEvent.listen(onLogEvent);
      _stdErrSub = _vmService.service.onStderrEvent.listen(onLogEvent);
      try {
        await _vmService.service.streamListen(vmservice.EventStreams.kStdout);
      } on vmservice.RPCError {
        // It is safe to ignore this error because we expect an error to be
        // thrown if we're not already subscribed.
      }
      try {
        await _vmService.service.streamListen(vmservice.EventStreams.kStderr);
      } on vmservice.RPCError {
        // It is safe to ignore this error because we expect an error to be
        // thrown if we're not already subscribed.
      }
      try {
        await _vmService.service.streamListen(vmservice.EventStreams.kIsolate);
      } on vmservice.RPCError {
        // It is safe to ignore this error because we expect an error to be
        // thrown if we're not already subscribed.
      }
      await setUpVmService(
        reloadSources: (String isolateId, {bool? force, bool? pause}) async {
          await restart(pause: pause);
        },
        device: device!.device,
        flutterProject: flutterProject,
        printStructuredErrorLogMethod: printStructuredErrorLog,
        vmService: _vmService.service,
      );

      websocketUri = Uri.parse(_connectionResult!.debugConnection!.uri);
      device!.vmService = _vmService;

      // Run main immediately if the app is not started paused or if there
      // is no debugger attached. Otherwise, runMain when a resume event
      // is received.
      if (!debuggingOptions.startPaused || !supportsServiceProtocol) {
        _connectionResult!.appConnection!.runMain();
      } else {
        late StreamSubscription<void> resumeSub;
        resumeSub = _vmService.service.onDebugEvent.listen((vmservice.Event event) {
          if (event.type == vmservice.EventKind.kResume) {
            _connectionResult!.appConnection!.runMain();
            resumeSub.cancel();
          }
        });
      }
      if (enableDevTools) {
        // The method below is guaranteed never to return a failing future.
        unawaited(residentDevtoolsHandler!.serveAndAnnounceDevTools(
          devToolsServerAddress: debuggingOptions.devToolsServerAddress,
          flutterDevices: flutterDevices,
        ));
      }
    }
    if (websocketUri != null) {
      if (debuggingOptions.vmserviceOutFile != null) {
        _fileSystem.file(debuggingOptions.vmserviceOutFile)
          ..createSync(recursive: true)
          ..writeAsStringSync(websocketUri.toString());
      }
      _logger.printStatus('Debug service listening on $websocketUri');
      if (debuggingOptions.buildInfo.nullSafetyMode != NullSafetyMode.sound) {
        _logger.printStatus('');
        _logger.printStatus(
          'Running without sound null safety ⚠️',
          emphasis: true,
        );
        _logger.printStatus(
          'Dart 3 will only support sound null safety, see https://dart.dev/null-safety',
        );
      }
    }
    appStartedCompleter?.complete();
    connectionInfoCompleter?.complete(DebugConnectionInfo(wsUri: websocketUri));
    if (stayResident) {
      await waitForAppToFinish();
    } else {
      await stopEchoingDeviceLog();
      await exitApp();
    }
    await cleanupAtFinish();
    return 0;
  }

  @override
  Future<void> exitApp() async {
    await device!.exitApps();
    appFinished();
  }
}

Uri _httpUriFromWebsocketUri(Uri websocketUri) {
  const String wsPath = '/ws';
  final String path = websocketUri.path;
  return websocketUri.replace(scheme: 'http', path: path.substring(0, path.length - wsPath.length));
}