Remove the timeout when launching DevTools (flutter#74859)

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

@@ -103,7 +103,7 @@ class AttachCommand extends FlutterCommand {
       );
     usesTrackWidgetCreation(verboseHelp: verboseHelp);
     addDdsOptions(verboseHelp: verboseHelp);
-    addDevToolsOptions();
+    addDevToolsOptions(verboseHelp: verboseHelp);
     usesDeviceTimeoutOption();
     hotRunnerFactory ??= HotRunnerFactory();
   }
@@ -207,7 +207,8 @@ known, it can be explicitly provided to attach via the command-line, e.g.
       body: () => _attachToDevice(device),
       overrides: <Type, Generator>{
         Artifacts: () => overrideArtifacts,
-    });
+      },
+    );
 
     return FlutterCommandResult.success();
   }
@@ -327,6 +328,7 @@ known, it can be explicitly provided to attach via the command-line, e.g.
                 connectionInfoCompleter: connectionInfoCompleter,
                 appStartedCompleter: appStartedCompleter,
                 allowExistingDdsInstance: true,
+                enableDevTools: boolArg(FlutterCommand.kEnableDevTools),
               );
             },
             device,
@@ -365,6 +367,7 @@ known, it can be explicitly provided to attach via the command-line, e.g.
         result = await runner.attach(
           appStartedCompleter: onAppStart,
           allowExistingDdsInstance: true,
+          enableDevTools: boolArg(FlutterCommand.kEnableDevTools),
         );
         if (result != 0) {
           throwToolExit(null, exitCode: result);

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

@@ -515,6 +515,7 @@ class AppDomain extends Domain {
         return runner.run(
           connectionInfoCompleter: connectionInfoCompleter,
           appStartedCompleter: appStartedCompleter,
+          enableDevTools: true,
           route: route,
         );
       },

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

@@ -136,7 +136,7 @@ abstract class RunCommandBase extends FlutterCommand with DeviceBasedDevelopment
     usesDeviceUserOption();
     usesDeviceTimeoutOption();
     addDdsOptions(verboseHelp: verboseHelp);
-    addDevToolsOptions();
+    addDevToolsOptions(verboseHelp: verboseHelp);
     addAndroidSpecificBuildOptions(hide: !verboseHelp);
   }
 
@@ -621,6 +621,7 @@ class RunCommand extends RunCommandBase {
 
     final int result = await runner.run(
       appStartedCompleter: appStartedTimeRecorder,
+      enableDevTools: stayResident && boolArg(FlutterCommand.kEnableDevTools),
       route: route,
     );
     if (result != 0) {

packages/flutter_tools/lib/src/devtools_launcher.dart

@@ -48,8 +48,7 @@ class DevtoolsServerLauncher extends DevtoolsLauncher {
   @override
   Future<void> launch(Uri vmServiceUri) async {
     // Place this entire method in a try/catch that swallows exceptions because
-    // we do not want to block Flutter run/attach operations on a DevTools
-    // failure.
+    // this method is guaranteed not to return a Future that throws.
     try {
       bool offline = false;
       try {
@@ -109,8 +108,7 @@ class DevtoolsServerLauncher extends DevtoolsLauncher {
           .transform(utf8.decoder)
           .transform(const LineSplitter())
           .listen(_logger.printError);
-      devToolsUri = await completer.future
-        .timeout(const Duration(seconds: 10));
+      devToolsUrl = await completer.future;
     } on Exception catch (e, st) {
       _logger.printError('Failed to launch DevTools: $e', stackTrace: st);
     }
@@ -124,7 +122,6 @@ class DevtoolsServerLauncher extends DevtoolsLauncher {
       'global',
       'list',
     ]);
-
     if (_pubGlobalListProcess.stdout.toString().contains('devtools ')) {
       return true;
     }
@@ -144,7 +141,6 @@ class DevtoolsServerLauncher extends DevtoolsLauncher {
     if (!shouldActivate) {
       return false;
     }
-
     final Status status = _logger.startProgress(
       'Activating Dart DevTools...',
     );
@@ -182,7 +178,7 @@ class DevtoolsServerLauncher extends DevtoolsLauncher {
 
   @override
   Future<void> close() async {
-    devToolsUri = null;
+    devToolsUrl = null;
     if (_devToolsProcess != null) {
       _devToolsProcess.kill();
       await _devToolsProcess.exitCode;

packages/flutter_tools/lib/src/drive/web_driver_service.dart

@@ -76,6 +76,7 @@ class WebDriverService extends DriverService {
     final Completer<void> appStartedCompleter = Completer<void>.sync();
     final int result = await _residentRunner.run(
       appStartedCompleter: appStartedCompleter,
+      enableDevTools: false,
       route: route,
     );
     _webUri = _residentRunner.uri;

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

@@ -454,6 +454,7 @@ class _ResidentWebRunner extends ResidentWebRunner {
   Future<int> run({
     Completer<DebugConnectionInfo> connectionInfoCompleter,
     Completer<void> appStartedCompleter,
+    bool enableDevTools = false, // ignored, we don't yet support devtools for web
     String route,
   }) async {
     firstBuildTime = DateTime.now();
@@ -531,6 +532,7 @@ class _ResidentWebRunner extends ResidentWebRunner {
         return attach(
           connectionInfoCompleter: connectionInfoCompleter,
           appStartedCompleter: appStartedCompleter,
+          enableDevTools: enableDevTools,
         );
       });
     } on WebSocketException {
@@ -745,6 +747,7 @@ class _ResidentWebRunner extends ResidentWebRunner {
     Completer<DebugConnectionInfo> connectionInfoCompleter,
     Completer<void> appStartedCompleter,
     bool allowExistingDdsInstance = false,
+    bool enableDevTools = false, // ignored, we don't yet support devtools for web
   }) async {
     if (_chromiumLauncher != null) {
       final Chromium chrome = await _chromiumLauncher.connectedInstance;

packages/flutter_tools/lib/src/resident_runner.dart

@@ -795,6 +795,8 @@ abstract class ResidentRunner {
   final CommandHelp commandHelp;
   final bool machine;
 
+  @visibleForTesting
+  DevtoolsLauncher get devToolsLauncher => _devToolsLauncher;
   DevtoolsLauncher _devToolsLauncher;
 
   bool _exited = false;
@@ -878,13 +880,15 @@ abstract class ResidentRunner {
   Future<int> run({
     Completer<DebugConnectionInfo> connectionInfoCompleter,
     Completer<void> appStartedCompleter,
+    bool enableDevTools = false,
     String route,
   });
 
   Future<int> attach({
     Completer<DebugConnectionInfo> connectionInfoCompleter,
     Completer<void> appStartedCompleter,
     bool allowExistingDdsInstance = false,
+    bool enableDevTools = false,
   });
 
   bool get supportsRestart => false;
@@ -1275,19 +1279,26 @@ abstract class ResidentRunner {
     return _devToolsLauncher.activeDevToolsServer;
   }
 
-  Future<void> serveDevToolsGracefully({
-    Uri devToolsServerAddress
+  // This must be guaranteed not to return a Future that fails.
+  Future<void> serveAndAnnounceDevTools({
+    Uri devToolsServerAddress,
   }) async {
     if (!supportsServiceProtocol) {
       return;
     }
-
     _devToolsLauncher ??= DevtoolsLauncher.instance;
     if (devToolsServerAddress != null) {
-      _devToolsLauncher.devToolsUri = devToolsServerAddress;
+      _devToolsLauncher.devToolsUrl = devToolsServerAddress;
     } else {
-      await _devToolsLauncher.serve();
+      unawaited(_devToolsLauncher.serve());
+    }
+    await _devToolsLauncher.ready;
+    if (_reportedDebuggers) {
+      // Since the DevTools only just became available, we haven't had a chance to
+      // report their URLs yet. Do so now.
+      printDebuggerList(includeObservatory: false);
     }
+    await maybeCallDevToolsUriServiceExtension();
   }
 
   Future<void> maybeCallDevToolsUriServiceExtension() async {
@@ -1417,6 +1428,39 @@ abstract class ResidentRunner {
     appFinished();
   }
 
+  bool _reportedDebuggers = false;
+
+  void printDebuggerList({ bool includeObservatory = true, bool includeDevtools = true }) {
+    final DevToolsServerAddress devToolsServerAddress = activeDevToolsServer();
+    if (devToolsServerAddress == null) {
+      includeDevtools = false;
+    }
+    for (final FlutterDevice device in flutterDevices) {
+      if (device.vmService == null) {
+        continue;
+      }
+      if (includeObservatory) {
+        // Caution: This log line is parsed by device lab tests.
+        globals.printStatus(
+          'An Observatory debugger and profiler on ${device.device.name} is available at: '
+          '${device.vmService.httpAddress}',
+        );
+      }
+      if (includeDevtools) {
+        final Uri uri = devToolsServerAddress.uri?.replace(
+          queryParameters: <String, dynamic>{'uri': '${device.vmService.httpAddress}'},
+        );
+        if (uri != null) {
+          globals.printStatus(
+            'The Flutter DevTools debugger and profiler '
+            'on ${device.device.name} is available at: $uri',
+          );
+        }
+      }
+    }
+    _reportedDebuggers = true;
+  }
+
   /// Called to print help to the terminal.
   void printHelp({ @required bool details });
 
@@ -1763,24 +1807,51 @@ String nextPlatform(String currentPlatform, FeatureFlags featureFlags) {
 
 /// A launcher for the devtools debugger and analysis tool.
 abstract class DevtoolsLauncher {
-  Uri devToolsUri;
+  static DevtoolsLauncher get instance => context.get<DevtoolsLauncher>();
+
+  /// Serve Dart DevTools and return the host and port they are available on.
+  ///
+  /// This method must return a future that is guaranteed not to fail, because it
+  /// will be used in unawaited contexts. It may, however, return null.
+  Future<DevToolsServerAddress> serve();
 
   /// Launch a Dart DevTools process, optionally targeting a specific VM Service
   /// URI if [vmServiceUri] is non-null.
+  ///
+  /// This method must return a future that is guaranteed not to fail, because it
+  /// will be used in unawaited contexts.
+  @visibleForTesting
   Future<void> launch(Uri vmServiceUri);
 
-  /// Serve Dart DevTools and return the host and port they are available on.
-  Future<DevToolsServerAddress> serve();
-
   Future<void> close();
 
-  static DevtoolsLauncher get instance => context.get<DevtoolsLauncher>();
+  /// Returns a future that completes when the DevTools server is ready.
+  ///
+  /// Completes when [devToolsUrl] is set. That can be set either directly, or
+  /// by calling [serve].
+  Future<void> get ready => _readyCompleter.future;
+  Completer<void> _readyCompleter = Completer<void>();
+
+  Uri get devToolsUrl => _devToolsUrl;
+  Uri _devToolsUrl;
+  set devToolsUrl(Uri value) {
+    assert((_devToolsUrl == null) != (value == null));
+    _devToolsUrl = value;
+    if (_devToolsUrl != null) {
+      _readyCompleter.complete();
+    } else {
+      _readyCompleter = Completer<void>();
+    }
+  }
 
+  /// The URL of the current DevTools server.
+  ///
+  /// Returns null if [ready] is not complete.
   DevToolsServerAddress get activeDevToolsServer {
-    if (devToolsUri == null) {
+    if (_devToolsUrl == null) {
       return null;
     }
-    return DevToolsServerAddress(devToolsUri.host, devToolsUri.port);
+    return DevToolsServerAddress(devToolsUrl.host, devToolsUrl.port);
   }
 }