[flutter_tools] Fix parsing of existing DDS URIs from exceptions (#119506)

* [flutter_tools] Fix parsing of existing DDS URIs from exceptions

Fixes #118609.

* Fix formatting
Co-authored-by: Christopher Fujino <fujino@google.com>

* Fix formatting
Co-authored-by: Christopher Fujino <fujino@google.com>

---------
Co-authored-by: Christopher Fujino <fujino@google.com>

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

@@ -71,9 +71,21 @@ class DartDevelopmentService {
       logger.printTrace('Warning: Failed to start DDS: ${e.message}');
       if (e.errorCode == dds.DartDevelopmentServiceException.existingDdsInstanceError) {
         try {
-          _existingDdsUri = Uri.parse(
-            e.message.split(' ').firstWhere((String e) => e.startsWith('http'))
-          );
+          // First try to use the new field to avoid parsing from the message.
+          _existingDdsUri = e is dds.ExistingDartDevelopmentServiceException ? e.ddsUri : null;
+
+            // Otherwise, fall back to parsing from the exception (old DDS).
+            // This is not completely reliable which is why the new field above
+            // was added.
+            if (_existingDdsUri == null) {
+              String parsedUrl = e.message.split(' ').firstWhere((String e) => e.startsWith('http'));
+              // Trim trailing full stops from the message.
+              // https://github.com/flutter/flutter/issues/118609.
+              if (parsedUrl.endsWith('.')) {
+                parsedUrl = parsedUrl.substring(0, parsedUrl.length - 1);
+              }
+              _existingDdsUri ??= Uri.parse(parsedUrl);
+            }
         } on StateError {
           if (e.message.contains('Existing VM service clients prevent DDS from taking control.')) {
             throwToolExit('${e.message}. Please rebuild your application with a newer version of Flutter.');

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

@@ -2158,6 +2158,73 @@ flutter:
     }) async => FakeVmServiceHost(requests: <VmServiceExpectation>[]).vmService,
   }));
 
+  testUsingContext('Uses existing DDS URI from exception field', () => testbed.run(() async {
+    fakeVmServiceHost = FakeVmServiceHost(requests: <VmServiceExpectation>[]);
+    final FakeDevice device = FakeDevice()
+      ..dds = DartDevelopmentService();
+    ddsLauncherCallback = (Uri uri, {bool enableAuthCodes = true, bool ipv6 = false, Uri? serviceUri, List<String> cachedUserTags = const <String>[], dds.UriConverter? uriConverter}) {
+      throw dds.DartDevelopmentServiceException.existingDdsInstance(
+        'Existing DDS at http://localhost/existingDdsInMessage.',
+        ddsUri: Uri.parse('http://localhost/existingDdsInField'),
+      );
+    };
+    final TestFlutterDevice flutterDevice = TestFlutterDevice(
+      device,
+      observatoryUris: Stream<Uri>.value(testUri),
+    );
+    final Completer<void> done = Completer<void>();
+    await runZonedGuarded(
+      () => flutterDevice.connect(allowExistingDdsInstance: true).then((_) => done.complete()),
+      (_, __) => done.complete(),
+    );
+    await done.future;
+    expect(device.dds.uri, Uri.parse('http://localhost/existingDdsInField'));
+  }, overrides: <Type, Generator>{
+    VMServiceConnector: () => (Uri httpUri, {
+      ReloadSources? reloadSources,
+      Restart? restart,
+      CompileExpression? compileExpression,
+      GetSkSLMethod? getSkSLMethod,
+      PrintStructuredErrorLogMethod? printStructuredErrorLogMethod,
+      io.CompressionOptions? compression,
+      Device? device,
+      required Logger logger,
+    }) async => FakeVmServiceHost(requests: <VmServiceExpectation>[]).vmService,
+  }));
+
+  testUsingContext('Falls back to existing DDS URI from exception message', () => testbed.run(() async {
+    fakeVmServiceHost = FakeVmServiceHost(requests: <VmServiceExpectation>[]);
+    final FakeDevice device = FakeDevice()
+      ..dds = DartDevelopmentService();
+    ddsLauncherCallback = (Uri uri, {bool enableAuthCodes = true, bool ipv6 = false, Uri? serviceUri, List<String> cachedUserTags = const <String>[], dds.UriConverter? uriConverter}) {
+      throw dds.DartDevelopmentServiceException.existingDdsInstance(
+        'Existing DDS at http://localhost/existingDdsInMessage.',
+      );
+    };
+    final TestFlutterDevice flutterDevice = TestFlutterDevice(
+      device,
+      observatoryUris: Stream<Uri>.value(testUri),
+    );
+    final Completer<void>done = Completer<void>();
+    await runZonedGuarded(
+      () => flutterDevice.connect(allowExistingDdsInstance: true).then((_) => done.complete()),
+      (_, __) => done.complete(),
+    );
+    await done.future;
+    expect(device.dds.uri, Uri.parse('http://localhost/existingDdsInMessage'));
+  }, overrides: <Type, Generator>{
+    VMServiceConnector: () => (Uri httpUri, {
+      ReloadSources? reloadSources,
+      Restart? restart,
+      CompileExpression? compileExpression,
+      GetSkSLMethod? getSkSLMethod,
+      PrintStructuredErrorLogMethod? printStructuredErrorLogMethod,
+      io.CompressionOptions? compression,
+      Device? device,
+      required Logger logger,
+    }) async => FakeVmServiceHost(requests: <VmServiceExpectation>[]).vmService,
+  }));
+
   testUsingContext('Host VM service ipv6 defaults', () => testbed.run(() async {
     fakeVmServiceHost = FakeVmServiceHost(requests: <VmServiceExpectation>[]);
     final FakeDevice device = FakeDevice()