Allow web server device to use extension if started with --start-paused (#44263)

* Allow web server device to use extension if started with --start-paused

* Fix comment

* Remove browser-launch option that allowed using Chrome without launching Chrome

The web-server device should now be used if you don't want to launch a browser.

* Add tests for WebServerDevice with --start-paused

* Fixes from rebase

* More fixes from rebase

* Fix from rebase

* Fix condition for page refresh in non-debug builds

* Make dwds conditions match with a new getter

* Add missing .device

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

@@ -96,12 +96,15 @@ abstract class ResidentWebRunner extends ResidentRunner {
 
   // Only the debug builds of the web support the service protocol.
   @override
-  bool get supportsServiceProtocol =>
-      isRunningDebug && device.device is! WebServerDevice;
+  bool get supportsServiceProtocol => isRunningDebug && deviceIsDebuggable;
 
   @override
-  bool get debuggingEnabled =>
-      isRunningDebug && device.device is! WebServerDevice;
+  bool get debuggingEnabled => isRunningDebug && deviceIsDebuggable;
+
+  /// WebServer device is debuggable when running with --start-paused.
+  bool get deviceIsDebuggable => device.device is! WebServerDevice || debuggingOptions.startPaused;
+
+  bool get _enableDwds => debuggingEnabled;
 
   WebFs _webFs;
   ConnectionResult _connectionResult;
@@ -602,14 +605,14 @@ class _DwdsResidentWebRunner extends ResidentWebRunner {
           initializePlatform: debuggingOptions.initializePlatform,
           hostname: debuggingOptions.hostname,
           port: debuggingOptions.port,
-          skipDwds: device.device is WebServerDevice || !debuggingOptions.buildInfo.isDebug,
+          skipDwds: !_enableDwds,
           dartDefines: dartDefines,
         );
         // When connecting to a browser, update the message with a seemsSlow notification
         // to handle the case where we fail to connect.
         buildStatus.stop();
         statusActive = false;
-        if (debuggingOptions.browserLaunch && supportsServiceProtocol) {
+        if (supportsServiceProtocol) {
           buildStatus = logger.startProgress(
             'Attempting to connect to browser instance..',
             timeout: const Duration(seconds: 30),
@@ -624,8 +627,9 @@ class _DwdsResidentWebRunner extends ResidentWebRunner {
             'uri': _webFs.uri,
           },
         );
-        if (supportsServiceProtocol) {
-          _connectionResult = await _webFs.connect(debuggingOptions);
+        if (_enableDwds) {
+          final bool useDebugExtension = device.device is WebServerDevice && debuggingOptions.startPaused;
+          _connectionResult = await _webFs.connect(useDebugExtension);
           unawaited(_connectionResult.debugConnection.onDone.whenComplete(_cleanupAndExit));
         }
         if (statusActive) {
@@ -741,7 +745,7 @@ class _DwdsResidentWebRunner extends ResidentWebRunner {
       }
     }
     // Allows browser refresh hot restart on non-debug builds.
-    if (device is ChromeDevice && debuggingOptions.browserLaunch) {
+    if (device.device is ChromeDevice && !isRunningDebug) {
       try {
         final Chrome chrome = await ChromeLauncher.connectedInstance;
         final ChromeTab chromeTab = await chrome.chromeConnection.getTab((ChromeTab chromeTab) {

packages/flutter_tools/lib/src/build_runner/web_fs.dart

@@ -33,7 +33,6 @@ import '../bundle.dart';
 import '../cache.dart';
 import '../dart/package_map.dart';
 import '../dart/pub.dart';
-import '../device.dart';
 import '../globals.dart';
 import '../platform_plugins.dart';
 import '../plugins.dart';
@@ -131,12 +130,12 @@ class WebFs {
   /// Connect and retrieve the [DebugConnection] for the current application.
   ///
   /// Only calls [AppConnection.runMain] on the subsequent connections.
-  Future<ConnectionResult> connect(DebuggingOptions debuggingOptions) {
+  Future<ConnectionResult> connect(bool useDebugExtension) {
     final Completer<ConnectionResult> firstConnection = Completer<ConnectionResult>();
     _connectedApps = _dwds.connectedApps.listen((AppConnection appConnection) async {
-      final DebugConnection debugConnection = debuggingOptions.browserLaunch
-        ? await _dwds.debugConnection(appConnection)
-        : await (_cachedExtensionFuture ??= _dwds.extensionDebugConnections.stream.first);
+      final DebugConnection debugConnection = useDebugExtension
+        ? await (_cachedExtensionFuture ??= _dwds.extensionDebugConnections.stream.first)
+        : await _dwds.debugConnection(appConnection);
       if (!firstConnection.isCompleted) {
         firstConnection.complete(ConnectionResult(appConnection, debugConnection));
       } else {

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

@@ -321,7 +321,6 @@ class RunCommand extends RunCommandBase {
         initializePlatform: boolArg('web-initialize-platform'),
         hostname: featureFlags.isWebEnabled ? stringArg('web-hostname') : '',
         port: featureFlags.isWebEnabled ? stringArg('web-port') : '',
-        browserLaunch: featureFlags.isWebEnabled ? boolArg('web-browser-launch') : null,
         vmserviceOutFile: stringArg('vmservice-out-file'),
       );
     }

packages/flutter_tools/lib/src/device.dart

@@ -506,7 +506,6 @@ class DebuggingOptions {
     this.initializePlatform = true,
     this.hostname,
     this.port,
-    this.browserLaunch = true,
     this.vmserviceOutFile,
    }) : debuggingEnabled = true;
 
@@ -524,7 +523,6 @@ class DebuggingOptions {
       verboseSystemLogs = false,
       hostVmServicePort = null,
       deviceVmServicePort = null,
-      browserLaunch = true,
       vmserviceOutFile = null;
 
   final bool debuggingEnabled;
@@ -547,7 +545,6 @@ class DebuggingOptions {
   final int deviceVmServicePort;
   final String port;
   final String hostname;
-  final bool browserLaunch;
   /// A file where the vmservice uri should be written after the application is started.
   final String vmserviceOutFile;
 

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

@@ -150,14 +150,6 @@ abstract class FlutterCommand extends Command<void> {
         'will select a random open port on the host.',
       hide: hide,
     );
-    argParser.addFlag('web-browser-launch',
-      defaultsTo: true,
-      negatable: true,
-      help: 'Whether to automatically launch browsers for web devices '
-        'that do so. Setting this to true allows using the Dart debug extension '
-        'on Chrome and other browsers which support extensions.',
-      hide: hide,
-    );
   }
 
   void usesTargetOption() {

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

@@ -134,16 +134,13 @@ class ChromeDevice extends Device {
     // See [ResidentWebRunner.run] in flutter_tools/lib/src/resident_web_runner.dart
     // for the web initialization and server logic.
     final String url = platformArgs['uri'] as String;
-    if (debuggingOptions.browserLaunch) {
-      _chrome = await chromeLauncher.launch(url,
-        dataDir: fs.currentDirectory
-          .childDirectory('.dart_tool')
-          .childDirectory('chrome-device'));
-      logger.sendEvent('app.webLaunchUrl', <String, dynamic>{'url': url, 'launched': true});
-    } else {
-      printStatus('Waiting for connection from Dart debug extension at $url', emphasis: true);
-      logger.sendEvent('app.webLaunchUrl', <String, dynamic>{'url': url, 'launched': false});
-    }
+    _chrome = await chromeLauncher.launch(url,
+      dataDir: fs.currentDirectory
+        .childDirectory('.dart_tool')
+        .childDirectory('chrome-device'));
+
+    logger.sendEvent('app.webLaunchUrl', <String, dynamic>{'url': url, 'launched': true});
+
     return LaunchResult.succeeded(observatoryUri: null);
   }
 
@@ -253,7 +250,11 @@ class WebServerDevice extends Device {
     bool ipv6 = false,
   }) async {
     final String url = platformArgs['uri'] as String;
-    printStatus('$mainPath is being served at $url', emphasis: true);
+    if (debuggingOptions.startPaused) {
+      printStatus('Waiting for connection from Dart debug extension at $url', emphasis: true);
+    } else {
+      printStatus('$mainPath is being served at $url', emphasis: true);
+    }
     logger.sendEvent('app.webLaunchUrl', <String, dynamic>{'url': url, 'launched': false});
     return LaunchResult.succeeded(observatoryUri: null);
   }

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

@@ -130,7 +130,7 @@ void main() {
     when(mockWipConnection.debugger).thenReturn(mockWipDebugger);
   }
 
-  test('runner with web server device does not support debugging', () => testbed.run(() async {
+  test('runner with web server device does not support debugging without --start-paused', () => testbed.run(() {
     when(mockFlutterDevice.device).thenReturn(WebServerDevice());
     final ResidentRunner profileResidentWebRunner = DwdsWebRunnerFactory().createWebRunner(
       mockFlutterDevice,
@@ -144,7 +144,6 @@ void main() {
     expect(profileResidentWebRunner.debuggingEnabled, false);
 
     when(mockFlutterDevice.device).thenReturn(MockChromeDevice());
-
     expect(residentWebRunner.debuggingEnabled, true);
   }));
 
@@ -161,6 +160,45 @@ void main() {
     expect(didSkipDwds, true);
   }));
 
+  test('runner with web server device supports debugging with --start-paused', () => testbed.run(() {
+    when(mockFlutterDevice.device).thenReturn(WebServerDevice());
+    final ResidentRunner profileResidentWebRunner = DwdsWebRunnerFactory().createWebRunner(
+      mockFlutterDevice,
+      flutterProject: FlutterProject.current(),
+      debuggingOptions: DebuggingOptions.enabled(BuildInfo.debug, startPaused: true),
+      ipv6: true,
+      stayResident: true,
+      dartDefines: <String>[],
+    );
+
+    expect(profileResidentWebRunner.debuggingEnabled, true);
+  }));
+
+  test('runner with web server device uses debug extension with --start-paused', () => testbed.run(() async {
+    _setupMocks();
+    when(mockFlutterDevice.device).thenReturn(WebServerDevice());
+    final BufferLogger bufferLogger = logger;
+
+    final ResidentWebRunner runner = DwdsWebRunnerFactory().createWebRunner(
+      mockFlutterDevice,
+      flutterProject: FlutterProject.current(),
+      debuggingOptions: DebuggingOptions.enabled(BuildInfo.debug, startPaused: true),
+      ipv6: true,
+      stayResident: true,
+      dartDefines: <String>[],
+    );
+
+    final Completer<DebugConnectionInfo> connectionInfoCompleter = Completer<DebugConnectionInfo>();
+     unawaited(runner.run(
+      connectionInfoCompleter: connectionInfoCompleter,
+    ));
+    await connectionInfoCompleter.future;
+
+    // Check connect() was told to use the debug extension.
+    verify(mockWebFs.connect(true)).called(1);
+    // And ensure the debug services was started.
+    expect(bufferLogger.statusText, contains('Debug service listening on'));
+  }));
 
   test('profile does not supportsServiceProtocol', () => testbed.run(() {
      when(mockFlutterDevice.device).thenReturn(mockChromeDevice);