Reland "Re-enable the Dart Development Service (DDS) (#64671)" (#64802)

* Reland "Re-enable the Dart Development Service (DDS) (#64671)"

This reverts commit 2ae25cc2.

* Fix MDNS building Observatory URI with port 0 instead of forwarding the device port

* Added MDNS test

packages/flutter_tools/lib/src/android/android_device.dart

@@ -620,7 +620,7 @@ class AndroidDevice extends Device {
       observatoryDiscovery = ProtocolDiscovery.observatory(
         await getLogReader(),
         portForwarder: portForwarder,
-        hostPort: debuggingOptions.hostVmServicePort,
+        hostPort: debuggingOptions.disableDds ? debuggingOptions.hostVmServicePort : 0,
         devicePort: debuggingOptions.deviceVmServicePort,
         ipv6: ipv6,
       );

packages/flutter_tools/lib/src/base/dds.dart

@@ -15,30 +15,24 @@ import 'logger.dart';
 class DartDevelopmentService {
   DartDevelopmentService({@required this.logger});
 
-  // TODO(bkonyi): enable once VM service can handle SSE forwarding for
-  // Devtools (https://github.com/flutter/flutter/issues/62507)
-  static const bool ddsDisabled = true;
   final Logger logger;
   dds.DartDevelopmentService _ddsInstance;
 
+  Uri get uri => _ddsInstance.uri;
+
   Future<void> startDartDevelopmentService(
     Uri observatoryUri,
+    int hostPort,
     bool ipv6,
+    bool disableServiceAuthCodes,
   ) async {
-    if (ddsDisabled) {
-      logger.printTrace(
-        'DDS is currently disabled due to '
-        'https://github.com/flutter/flutter/issues/62507'
-      );
-      return;
-    }
     final Uri ddsUri = Uri(
       scheme: 'http',
       host: (ipv6 ?
         io.InternetAddress.loopbackIPv6 :
         io.InternetAddress.loopbackIPv4
       ).host,
-      port: 0,
+      port: hostPort ?? 0,
     );
     logger.printTrace(
       'Launching a Dart Developer Service (DDS) instance at $ddsUri, '
@@ -48,6 +42,7 @@ class DartDevelopmentService {
       _ddsInstance = await dds.DartDevelopmentService.startDartDevelopmentService(
           observatoryUri,
           serviceUri: ddsUri,
+          enableAuthCodes: !disableServiceAuthCodes,
         );
       logger.printTrace('DDS is listening at ${_ddsInstance.uri}.');
     } on dds.DartDevelopmentServiceException catch (e) {

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

@@ -235,17 +235,22 @@ class DriveCommand extends RunCommandBase {
       }
       observatoryUri = result.observatoryUri.toString();
       // TODO(bkonyi): add web support (https://github.com/flutter/flutter/issues/61259)
-      if (!isWebPlatform) {
+      if (!isWebPlatform && !disableDds) {
         try {
           // If there's another flutter_tools instance still connected to the target
           // application, DDS will already be running remotely and this call will fail.
           // We can ignore this and continue to use the remote DDS instance.
-          await device.dds.startDartDevelopmentService(Uri.parse(observatoryUri), ipv6);
+          await device.dds.startDartDevelopmentService(
+            Uri.parse(observatoryUri),
+            hostVmservicePort,
+            ipv6,
+            disableServiceAuthCodes,
+          );
         } on dds.DartDevelopmentServiceException catch(_) {
           globals.printTrace('Note: DDS is already connected to $observatoryUri.');
         }
       }
-    } else {
+    } else if (isWebPlatform) {
       globals.printStatus('Will connect to already running application instance.');
       observatoryUri = stringArg('use-existing-app');
     }
@@ -478,7 +483,7 @@ Future<LaunchResult> _startApp(
     debuggingOptions: DebuggingOptions.enabled(
       command.getBuildInfo(),
       startPaused: true,
-      hostVmServicePort: command.hostVmservicePort,
+      hostVmServicePort: (webUri != null || command.disableDds) ? command.hostVmservicePort : 0,
       verboseSystemLogs: command.verboseSystemLogs,
       cacheSkSL: command.cacheSkSL,
       dumpSkpOnShaderCompilation: command.dumpSkpOnShaderCompilation,

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

@@ -66,7 +66,12 @@ abstract class RunCommandBase extends FlutterCommand with DeviceBasedDevelopment
         help: 'A file to write the attached vmservice uri to after an'
           ' application is started.',
         valueHelp: 'project/example/out.txt'
-      );
+      )
+      ..addFlag('disable-service-auth-codes',
+        negatable: false,
+        hide: !verboseHelp,
+        help: 'No longer require an authentication code to connect to the VM '
+              'service (not recommended).');
     usesWebOptions(hide: !verboseHelp);
     usesTargetOption();
     usesPortOptions();
@@ -75,13 +80,14 @@ abstract class RunCommandBase extends FlutterCommand with DeviceBasedDevelopment
     usesTrackWidgetCreation(verboseHelp: verboseHelp);
     addNullSafetyModeOptions(hide: !verboseHelp);
     usesDeviceUserOption();
+    addDdsOptions(verboseHelp: verboseHelp);
   }
 
   bool get traceStartup => boolArg('trace-startup');
   bool get cacheSkSL => boolArg('cache-sksl');
   bool get dumpSkpOnShaderCompilation => boolArg('dump-skp-on-shader-compilation');
   bool get purgePersistentCache => boolArg('purge-persistent-cache');
-
+  bool get disableServiceAuthCodes => boolArg('disable-service-auth-codes');
   String get route => stringArg('route');
 }
 
@@ -205,11 +211,6 @@ class RunCommand extends RunCommandBase {
               'results out to "refresh_benchmark.json", and exit. This flag is '
               'intended for use in generating automated flutter benchmarks.',
       )
-      ..addFlag('disable-service-auth-codes',
-        negatable: false,
-        hide: !verboseHelp,
-        help: 'No longer require an authentication code to connect to the VM '
-              'service (not recommended).')
       ..addFlag('web-initialize-platform',
         negatable: true,
         defaultsTo: true,
@@ -226,7 +227,6 @@ class RunCommand extends RunCommandBase {
               'Currently this is only supported on Android devices. This option '
               'cannot be paired with --use-application-binary.'
       );
-      addDdsOptions(verboseHelp: verboseHelp);
   }
 
   @override

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

@@ -130,6 +130,7 @@ class TestCommand extends FlutterCommand {
               'This flag is ignored if --start-paused or coverage are requested. '
               'The vmservice will be enabled no matter what in those cases.'
       );
+      addDdsOptions(verboseHelp: verboseHelp);
   }
 
   /// The interface for starting and configuring the tester.
@@ -254,6 +255,7 @@ class TestCommand extends FlutterCommand {
       enableObservatory: collector != null || startPaused || boolArg('enable-vmservice'),
       startPaused: startPaused,
       disableServiceAuthCodes: disableServiceAuthCodes,
+      disableDds: disableDds,
       ipv6: boolArg('ipv6'),
       machine: machine,
       buildMode: BuildMode.debug,

packages/flutter_tools/lib/src/desktop_device.dart

@@ -134,7 +134,7 @@ abstract class DesktopDevice extends Device {
     }
     final ProtocolDiscovery observatoryDiscovery = ProtocolDiscovery.observatory(_deviceLogReader,
       devicePort: debuggingOptions?.deviceVmServicePort,
-      hostPort: debuggingOptions?.hostVmServicePort,
+      hostPort: (debuggingOptions?.disableDds ?? false) ? debuggingOptions?.hostVmServicePort : 0,
       ipv6: ipv6,
     );
     try {

packages/flutter_tools/lib/src/fuchsia/fuchsia_device.dart

@@ -55,8 +55,14 @@ Future<vm_service.VmService> _kDefaultFuchsiaIsolateDiscoveryConnector(Uri uri)
 Future<void> _kDefaultDartDevelopmentServiceStarter(
   Device device,
   Uri observatoryUri,
+  bool disableServiceAuthCodes,
 ) async {
-  await device.dds.startDartDevelopmentService(observatoryUri, true);
+  await device.dds.startDartDevelopmentService(
+    observatoryUri,
+    0,
+    true,
+    disableServiceAuthCodes,
+  );
 }
 
 /// Read the log for a particular device.
@@ -738,7 +744,7 @@ class FuchsiaIsolateDiscoveryProtocol {
   final String _isolateName;
   final Completer<Uri> _foundUri = Completer<Uri>();
   final Future<vm_service.VmService> Function(Uri) _vmServiceConnector;
-  final Future<void> Function(Device, Uri) _ddsStarter;
+  final Future<void> Function(Device, Uri, bool) _ddsStarter;
   // whether to only poll once.
   final bool _pollOnce;
   Timer _pollingTimer;
@@ -781,8 +787,8 @@ class FuchsiaIsolateDiscoveryProtocol {
         final int localPort = await _device.portForwarder.forward(port);
         try {
           final Uri uri = Uri.parse('http://[$_ipv6Loopback]:$localPort');
-          await _ddsStarter(_device, uri);
-          service = await _vmServiceConnector(uri);
+          await _ddsStarter(_device, uri, true);
+          service = await _vmServiceConnector(_device.dds.uri);
           _ports[port] = service;
         } on SocketException catch (err) {
           globals.printTrace('Failed to connect to $localPort: $err');

packages/flutter_tools/lib/src/ios/devices.dart

@@ -399,7 +399,7 @@ class IOSDevice extends Device {
         observatoryDiscovery = ProtocolDiscovery.observatory(
           getLogReader(app: package),
           portForwarder: portForwarder,
-          hostPort: debuggingOptions.hostVmServicePort,
+          hostPort: debuggingOptions.disableDds ? debuggingOptions.hostVmServicePort : 0,
           devicePort: debuggingOptions.deviceVmServicePort,
           ipv6: ipv6,
         );
@@ -436,7 +436,7 @@ class IOSDevice extends Device {
         assumedDevicePort: assumedObservatoryPort,
         device: this,
         usesIpv6: ipv6,
-        hostVmservicePort: debuggingOptions.hostVmServicePort,
+        hostVmservicePort: debuggingOptions.disableDds ? debuggingOptions.hostVmServicePort : 0,
         packageId: packageId,
         packageName: FlutterProject.current().manifest.appName,
       );

packages/flutter_tools/lib/src/ios/simulators.dart

@@ -424,8 +424,11 @@ class IOSSimulator extends Device {
         if (debuggingOptions.skiaDeterministicRendering) '--skia-deterministic-rendering',
         if (debuggingOptions.useTestFonts) '--use-test-fonts',
         if (debuggingOptions.traceAllowlist != null) '--trace-allowlist="${debuggingOptions.traceAllowlist}"',
-        if (dartVmFlags.isNotEmpty) '--dart-flags=$dartVmFlags'
-        '--observatory-port=${debuggingOptions.hostVmServicePort ?? 0}',
+        if (dartVmFlags.isNotEmpty) '--dart-flags=$dartVmFlags',
+        if (debuggingOptions.disableDds)
+          '--observatory-port=${debuggingOptions.hostVmServicePort ?? 0}'
+        else
+          '--observatory-port=0'
       ],
     ];
 
@@ -434,7 +437,7 @@ class IOSSimulator extends Device {
       observatoryDiscovery = ProtocolDiscovery.observatory(
         getLogReader(app: package),
         ipv6: ipv6,
-        hostPort: debuggingOptions.hostVmServicePort,
+        hostPort: debuggingOptions.disableDds ? debuggingOptions.hostVmServicePort : 0,
         devicePort: debuggingOptions.deviceVmServicePort,
       );
     }

packages/flutter_tools/lib/src/mdns_discovery.dart

@@ -239,7 +239,9 @@ Future<Uri> buildObservatoryUri(
   if (!path.endsWith('/')) {
     path += '/';
   }
-  final int actualHostPort = hostVmservicePort ?? await device
-    .portForwarder.forward(devicePort);
+  hostVmservicePort ??= 0;
+  final int actualHostPort = hostVmservicePort == 0 ?
+    await device.portForwarder.forward(devicePort) :
+    hostVmservicePort;
   return Uri(scheme: 'http', host: host, port: actualHostPort, path: path);
 }

packages/flutter_tools/lib/src/resident_runner.dart

@@ -205,6 +205,8 @@ class FlutterDevice {
     ReloadMethod reloadMethod,
     GetSkSLMethod getSkSLMethod,
     PrintStructuredErrorLogMethod printStructuredErrorLogMethod,
+    int hostVmServicePort,
+    bool disableServiceAuthCodes = false,
     bool disableDds = false,
     bool ipv6 = false,
   }) {
@@ -220,12 +222,14 @@ class FlutterDevice {
       if (!disableDds) {
         await device.dds.startDartDevelopmentService(
           observatoryUri,
+          hostVmServicePort,
           ipv6,
+          disableServiceAuthCodes,
         );
       }
       try {
         service = await connectToVmService(
-          observatoryUri,
+          disableDds ? observatoryUri : device.dds.uri,
           reloadSources: reloadSources,
           restart: restart,
           compileExpression: compileExpression,
@@ -1232,10 +1236,12 @@ abstract class ResidentRunner {
         restart: restart,
         compileExpression: compileExpression,
         disableDds: debuggingOptions.disableDds,
+        hostVmServicePort: debuggingOptions.hostVmServicePort,
         reloadMethod: reloadMethod,
         getSkSLMethod: getSkSLMethod,
         printStructuredErrorLogMethod: printStructuredErrorLog,
         ipv6: ipv6,
+        disableServiceAuthCodes: debuggingOptions.disableServiceAuthCodes
       );
       // This will wait for at least one flutter view before returning.
       final Status status = globals.logger.startProgress(

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

@@ -312,6 +312,8 @@ abstract class FlutterCommand extends Command<void> {
     );
   }
 
+  bool get disableDds => boolArg('disable-dds');
+
   /// Gets the vmservice port provided to in the 'observatory-port' or
   /// 'host-vmservice-port option.
   ///

packages/flutter_tools/lib/src/test/flutter_platform.dart

@@ -4,6 +4,7 @@
 
 import 'dart:async';
 
+import 'package:dds/dds.dart';
 import 'package:meta/meta.dart';
 import 'package:package_config/package_config.dart';
 import 'package:stream_channel/stream_channel.dart';
@@ -52,6 +53,7 @@ FlutterPlatform installHook({
   bool machine = false,
   bool startPaused = false,
   bool disableServiceAuthCodes = false,
+  bool disableDds = false,
   int port = 0,
   String precompiledDillPath,
   Map<String, String> precompiledDillFiles,
@@ -89,6 +91,7 @@ FlutterPlatform installHook({
     enableObservatory: enableObservatory,
     startPaused: startPaused,
     disableServiceAuthCodes: disableServiceAuthCodes,
+    disableDds: disableDds,
     explicitObservatoryPort: observatoryPort,
     host: _kHosts[serverType],
     port: port,
@@ -233,6 +236,7 @@ class FlutterPlatform extends PlatformPlugin {
     this.machine,
     this.startPaused,
     this.disableServiceAuthCodes,
+    this.disableDds,
     this.explicitObservatoryPort,
     this.host,
     this.port,
@@ -255,6 +259,7 @@ class FlutterPlatform extends PlatformPlugin {
   final bool machine;
   final bool startPaused;
   final bool disableServiceAuthCodes;
+  final bool disableDds;
   final int explicitObservatoryPort;
   final InternetAddress host;
   final int port;
@@ -402,7 +407,7 @@ class FlutterPlatform extends PlatformPlugin {
         controllerSinkClosed = true;
       }));
 
-      // Prepare our WebSocket server to talk to the engine subproces.
+      // Prepare our WebSocket server to talk to the engine subprocess.
       final HttpServer server = await bind(host, port);
       finalizers.add(() async {
         globals.printTrace('test $ourTestCount: shutting down test harness socket server');
@@ -496,15 +501,16 @@ class FlutterPlatform extends PlatformPlugin {
           assert(processObservatoryUri == null);
           assert(explicitObservatoryPort == null ||
               explicitObservatoryPort == detectedUri.port);
-          if (startPaused && !machine) {
-            globals.printStatus('The test process has been started.');
-            globals.printStatus('You can now connect to it using observatory. To connect, load the following Web site in your browser:');
-            globals.printStatus('  $detectedUri');
-            globals.printStatus('You should first set appropriate breakpoints, then resume the test in the debugger.');
+          if (!disableDds) {
+            final DartDevelopmentService dds = await DartDevelopmentService.startDartDevelopmentService(
+              detectedUri,
+              enableAuthCodes: !disableServiceAuthCodes,
+            );
+            processObservatoryUri = dds.uri;
+            globals.printTrace('Dart Development Service started at ${dds.uri}, forwarding to VM service at ${dds.remoteVmServiceUri}.');
           } else {
-            globals.printTrace('test $ourTestCount: using observatory uri $detectedUri from pid ${process.pid}');
+            processObservatoryUri = detectedUri;
           }
-          processObservatoryUri = detectedUri;
           {
             globals.printTrace('Connecting to service protocol: $processObservatoryUri');
             final Future<vm_service.VmService> localVmService = connectToVmService(processObservatoryUri,
@@ -513,6 +519,14 @@ class FlutterPlatform extends PlatformPlugin {
               globals.printTrace('Successfully connected to service protocol: $processObservatoryUri');
             }));
           }
+          if (startPaused && !machine) {
+            globals.printStatus('The test process has been started.');
+            globals.printStatus('You can now connect to it using observatory. To connect, load the following Web site in your browser:');
+            globals.printStatus('  $processObservatoryUri');
+            globals.printStatus('You should first set appropriate breakpoints, then resume the test in the debugger.');
+          } else {
+            globals.printTrace('test $ourTestCount: using observatory uri $processObservatoryUri from pid ${process.pid}');
+          }
           gotProcessObservatoryUri.complete();
           watcher?.handleStartedProcess(
               ProcessEvent(ourTestCount, process, processObservatoryUri));

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

@@ -36,6 +36,7 @@ abstract class FlutterTestRunner {
     bool enableObservatory = false,
     bool startPaused = false,
     bool disableServiceAuthCodes = false,
+    bool disableDds = false,
     bool ipv6 = false,
     bool machine = false,
     String precompiledDillPath,
@@ -71,6 +72,7 @@ class _FlutterTestRunnerImpl implements FlutterTestRunner {
     bool enableObservatory = false,
     bool startPaused = false,
     bool disableServiceAuthCodes = false,
+    bool disableDds = false,
     bool ipv6 = false,
     bool machine = false,
     String precompiledDillPath,
@@ -169,6 +171,7 @@ class _FlutterTestRunnerImpl implements FlutterTestRunner {
       machine: machine,
       startPaused: startPaused,
       disableServiceAuthCodes: disableServiceAuthCodes,
+      disableDds: disableDds,
       serverType: serverType,
       precompiledDillPath: precompiledDillPath,
       precompiledDillFiles: precompiledDillFiles,

packages/flutter_tools/lib/src/tester/flutter_tester.dart

@@ -178,7 +178,7 @@ class FlutterTesterDevice extends Device {
       if (debuggingOptions.disableServiceAuthCodes)
         '--disable-service-auth-codes',
       if (debuggingOptions.hasObservatoryPort)
-        '--observatory-port=${debuggingOptions.hostVmServicePort}',
+        '--observatory-port=${debuggingOptions.disableDds ? debuggingOptions.hostVmServicePort : 0}',
       applicationKernelFilePath
     ];
 
@@ -205,7 +205,7 @@ class FlutterTesterDevice extends Device {
 
       observatoryDiscovery = ProtocolDiscovery.observatory(
         getLogReader(),
-        hostPort: debuggingOptions.hostVmServicePort,
+        hostPort: debuggingOptions.disableDds ? debuggingOptions.hostVmServicePort : 0,
         devicePort: debuggingOptions.deviceVmServicePort,
         ipv6: ipv6,
       );

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

@@ -90,8 +90,8 @@ void main() {
         when(portForwarder.unforward(any))
           .thenAnswer((_) async {});
         when(device.dds).thenReturn(mockDds);
-        when(mockDds.startDartDevelopmentService(any, false)).thenReturn(null);
-
+        when(mockDds.startDartDevelopmentService(any, any, false, any)).thenReturn(null);
+        when(mockDds.uri).thenReturn(Uri.parse('http://localhost:8181'));
         final HttpClientRequest httpClientRequest = MockHttpClientRequest();
         httpClient = MockHttpClient();
         when(httpClient.putUrl(any))
@@ -317,7 +317,8 @@ void main() {
       )).thenReturn(mockHotRunner);
       when(mockHotRunner.exited).thenReturn(false);
       when(mockHotRunner.isWaitingForObservatory).thenReturn(false);
-      when(mockDds.startDartDevelopmentService(any, false)).thenReturn(null);
+      when(mockDds.startDartDevelopmentService(any, any, false, any)).thenReturn(null);
+      when(mockDds.uri).thenReturn(Uri.parse('http://localhost:8181'));
 
       testDeviceManager.addDevice(device);
       when(device.getLogReader(includePastLogs: anyNamed('includePastLogs')))
@@ -396,7 +397,8 @@ void main() {
       )).thenReturn(mockHotRunner);
       when(mockHotRunner.exited).thenReturn(false);
       when(mockHotRunner.isWaitingForObservatory).thenReturn(false);
-      when(mockDds.startDartDevelopmentService(any, false)).thenReturn(null);
+      when(mockDds.startDartDevelopmentService(any, any, false, any)).thenReturn(null);
+      when(mockDds.uri).thenReturn(Uri.parse('http://localhost:8181'));
 
       testDeviceManager.addDevice(device);
 
@@ -442,8 +444,9 @@ void main() {
           .thenAnswer((_) async {});
         when(device.dds)
           .thenReturn(mockDds);
-        when(mockDds.startDartDevelopmentService(any, any))
+        when(mockDds.startDartDevelopmentService(any, any, any, any))
           .thenReturn(null);
+        when(mockDds.uri).thenReturn(Uri.parse('http://localhost:8181'));
       });
 
       testUsingContext('succeeds in ipv4 mode', () async {

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

@@ -71,7 +71,8 @@ void main() {
     void applyDdsMocks(Device device) {
       final MockDartDevelopmentService mockDds = MockDartDevelopmentService();
       when(device.dds).thenReturn(mockDds);
-      when(mockDds.startDartDevelopmentService(any, any)).thenReturn(null);
+      when(mockDds.startDartDevelopmentService(any, any, any, any)).thenReturn(null);
+      when(mockDds.uri).thenReturn(Uri.parse('http://localhost:8181'));
     }
 
     testUsingContext('returns 1 when test file is not found', () async {

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

@@ -168,6 +168,7 @@ class FakeFlutterTestRunner implements FlutterTestRunner {
     String excludeTags,
     bool enableObservatory = false,
     bool startPaused = false,
+    bool disableDds = false,
     bool disableServiceAuthCodes = false,
     bool ipv6 = false,
     bool machine = false,

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

@@ -140,6 +140,8 @@ class TestFlutterDevice extends FlutterDevice {
     GetSkSLMethod getSkSLMethod,
     PrintStructuredErrorLogMethod printStructuredErrorLogMethod,
     bool disableDds = false,
+    bool disableServiceAuthCodes = false,
+    int hostVmServicePort,
     bool ipv6 = false,
   }) async {
     throw exception;

packages/flutter_tools/test/general.shard/fuchsia/fuchsia_device_test.dart

@@ -10,6 +10,7 @@ import 'package:flutter_tools/src/application_package.dart';
 import 'package:flutter_tools/src/artifacts.dart';
 import 'package:flutter_tools/src/base/common.dart';
 import 'package:flutter_tools/src/base/context.dart';
+import 'package:flutter_tools/src/base/dds.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';
@@ -769,10 +770,13 @@ void main() {
         fuchsiaDevice,
         expectedIsolateName,
         (Uri uri) async => fakeVmServiceHost.vmService,
-        (Device device, Uri uri) => null,
+        (Device device, Uri uri, bool enableServiceAuthCodes) => null,
         true, // only poll once.
       );
-
+      final MockDartDevelopmentService mockDds = MockDartDevelopmentService();
+      when(fuchsiaDevice.dds).thenReturn(mockDds);
+      when(mockDds.startDartDevelopmentService(any, any, any, any)).thenReturn(null);
+      when(mockDds.uri).thenReturn(Uri.parse('example'));
       when(fuchsiaDevice.servicePorts())
           .thenAnswer((Invocation invocation) async => <int>[1]);
       when(portForwarder.forward(1))
@@ -1600,5 +1604,6 @@ class MockFuchsiaSdk extends Mock implements FuchsiaSdk {
   final FuchsiaDevFinder fuchsiaDevFinder;
 }
 
+class MockDartDevelopmentService extends Mock implements DartDevelopmentService {}
 class MockFuchsiaWorkflow extends Mock implements FuchsiaWorkflow {}
 class MockCache extends Mock implements Cache {}

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

@@ -578,8 +578,10 @@ class TestFlutterDevice extends FlutterDevice {
     ReloadMethod reloadMethod,
     GetSkSLMethod getSkSLMethod,
     PrintStructuredErrorLogMethod printStructuredErrorLogMethod,
+    bool disableServiceAuthCodes = false,
     bool disableDds = false,
     bool ipv6 = false,
+    int hostVmServicePort
   }) async {
     throw exception;
   }

packages/flutter_tools/test/general.shard/ios/ios_device_start_prebuilt_test.dart

@@ -7,6 +7,7 @@ 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/dds.dart';
 import 'package:flutter_tools/src/base/file_system.dart';
 import 'package:flutter_tools/src/base/io.dart' as io;
 import 'package:flutter_tools/src/base/logger.dart';
@@ -135,7 +136,8 @@ void main() {
     when(MDnsObservatoryDiscovery.instance.getObservatoryUri(
       any,
       any,
-      usesIpv6: anyNamed('usesIpv6')
+      usesIpv6: anyNamed('usesIpv6'),
+      hostVmservicePort: anyNamed('hostVmservicePort')
     )).thenAnswer((Invocation invocation) async => uri);
 
     final LaunchResult launchResult = await device.startApp(iosApp,
@@ -367,6 +369,7 @@ void main() {
       any,
       any,
       usesIpv6: anyNamed('usesIpv6'),
+      hostVmservicePort: anyNamed('hostVmservicePort')
     )).thenAnswer((Invocation invocation) async => uri);
 
     final LaunchResult launchResult = await device.startApp(iosApp,
@@ -454,3 +457,4 @@ class MockMDnsObservatoryDiscovery extends Mock implements MDnsObservatoryDiscov
 class MockArtifacts extends Mock implements Artifacts {}
 class MockCache extends Mock implements Cache {}
 class MockVmService extends Mock implements VmService {}
+class MockDartDevelopmentService extends Mock implements DartDevelopmentService {}
\ No newline at end of file

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

@@ -5,6 +5,7 @@
 import 'dart:async';
 
 import 'package:flutter_tools/src/base/io.dart';
+import 'package:flutter_tools/src/device.dart';
 import 'package:flutter_tools/src/mdns_discovery.dart';
 import 'package:mockito/mockito.dart';
 import 'package:multicast_dns/multicast_dns.dart';
@@ -207,6 +208,25 @@ void main() {
         throwsA(isA<Exception>()),
       );
     });
+
+    testUsingContext('Correctly builds Observatory URI with hostVmservicePort == 0', () async {
+      final MDnsClient client = getMockClient(
+        <PtrResourceRecord>[
+          PtrResourceRecord('foo', year3000, domainName: 'bar'),
+        ],
+        <String, List<SrvResourceRecord>>{
+          'bar': <SrvResourceRecord>[
+            SrvResourceRecord('bar', year3000, port: 123, weight: 1, priority: 1, target: 'appId'),
+          ],
+        },
+      );
+
+      final MockIOSDevice mockDevice = MockIOSDevice();
+      when(mockDevice.portForwarder).thenReturn(const NoOpDevicePortForwarder());
+      final MDnsObservatoryDiscovery portDiscovery = MDnsObservatoryDiscovery(mdnsClient: client);
+      final Uri uri = await portDiscovery.getObservatoryUri('bar', mockDevice, hostVmservicePort: 0);
+      expect(uri.toString(), 'http://127.0.0.1:123/');
+    });
   });
 }
 

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

@@ -2095,7 +2095,8 @@ void main() {
     final MockDeviceLogReader mockLogReader = MockDeviceLogReader();
     when(mockDevice.getLogReader(app: anyNamed('app'))).thenReturn(mockLogReader);
     when(mockDevice.dds).thenReturn(mockDds);
-    when(mockDds.startDartDevelopmentService(any, any)).thenReturn(null);
+    when(mockDds.startDartDevelopmentService(any, any, any, any)).thenReturn(null);
+    when(mockDds.uri).thenReturn(Uri.parse('http://localhost:8181'));
 
     final TestFlutterDevice flutterDevice = TestFlutterDevice(
       mockDevice,
@@ -2182,10 +2183,12 @@ class FakeFlutterDevice extends FlutterDevice {
     ReloadSources reloadSources,
     Restart restart,
     bool disableDds = false,
+    bool disableServiceAuthCodes = false,
     bool ipv6 = false,
     CompileExpression compileExpression,
     ReloadMethod reloadMethod,
     GetSkSLMethod getSkSLMethod,
+    int hostVmServicePort,
     PrintStructuredErrorLogMethod printStructuredErrorLogMethod,
   }) async { }
 

packages/flutter_tools/test/integration.shard/vmservice_integration_test.dart

@@ -6,7 +6,6 @@ import 'dart:async';
 import 'dart:io'; // ignore: dart_io_import
 
 import 'package:file/file.dart';
-import 'package:flutter_tools/src/base/dds.dart';
 import 'package:flutter_tools/src/base/file_system.dart';
 import 'package:matcher/matcher.dart';
 import 'package:vm_service/vm_service.dart';
@@ -47,7 +46,7 @@ void main() {
       for (final Protocol protocol in protocolList.protocols) {
         expect(protocol.protocolName, anyOf('VM Service', 'DDS'));
       }
-    }, skip: DartDevelopmentService.ddsDisabled);
+    });
 
     test('flutterVersion can be called', () async {
       final Response response =