Fix assert due to VSCode passing in an isolateId as well as the expected args...

Fix assert due to VSCode passing in an isolateId as well as the expected args to setPubRootDirectories. (#68721)

packages/flutter/lib/src/widgets/widget_inspector.dart

@@ -891,7 +891,9 @@ mixin WidgetInspectorService {
           }
           index++;
         }
-        assert(index == parameters.length);
+        // Verify that the only arguments other than perhaps 'isolateId' are
+        // arguments we have already handled.
+        assert(index == parameters.length || (index == parameters.length - 1 && parameters.containsKey('isolateId')));
         return <String, Object?>{'result': await callback(args)};
       },
     );

packages/flutter/test/widgets/widget_inspector_test.dart

@@ -1697,6 +1697,58 @@ class _TestWidgetInspectorService extends TestWidgetInspectorService {
       expect(await service.testExtension('getSelectedWidget', <String, String>{'objectGroup': 'my-group'}), contains('createdByLocalProject'));
     }, skip: !WidgetInspectorService.instance.isWidgetCreationTracked() || isBrowser); // Test requires --track-widget-creation flag.
 
+    testWidgets('ext.flutter.inspector.setPubRootDirectories extra args regression test', (WidgetTester tester) async {
+      // Ensure that passing the isolate id as an argument won't break
+      // setPubRootDirectories command.
+      await tester.pumpWidget(
+        Directionality(
+          textDirection: TextDirection.ltr,
+          child: Stack(
+            children: const <Widget>[
+              Text('a'),
+              Text('b', textDirection: TextDirection.ltr),
+              Text('c', textDirection: TextDirection.ltr),
+            ],
+          ),
+        ),
+      );
+      final Element elementA = find.text('a').evaluate().first;
+
+      await service.testExtension('setPubRootDirectories', <String, String>{'isolateId': '34'});
+      service.setSelection(elementA, 'my-group');
+      final Map<String, Object?> jsonObject = (await service.testExtension('getSelectedWidget', <String, String>{'objectGroup': 'my-group'}))! as Map<String, Object?>;
+      final Map<String, Object?> creationLocation = jsonObject['creationLocation']! as Map<String, Object?>;
+      expect(creationLocation, isNotNull);
+      final String fileA = creationLocation['file']! as String;
+      expect(fileA, endsWith('widget_inspector_test.dart'));
+      expect(jsonObject, isNot(contains('createdByLocalProject')));
+      final List<String> segments = Uri.parse(fileA).pathSegments;
+      // Strip a couple subdirectories away to generate a plausible pub root
+      // directory.
+      final String pubRootTest = '/' + segments.take(segments.length - 2).join('/');
+      await service.testExtension('setPubRootDirectories', <String, String>{'arg0': pubRootTest, 'isolateId': '34'});
+
+      service.setSelection(elementA, 'my-group');
+      expect(await service.testExtension('getSelectedWidget', <String, String>{'objectGroup': 'my-group'}), contains('createdByLocalProject'));
+
+      await service.testExtension('setPubRootDirectories', <String, String>{'arg0': '/invalid/$pubRootTest', 'isolateId': '34'});
+      expect(await service.testExtension('getSelectedWidget', <String, String>{'objectGroup': 'my-group'}), isNot(contains('createdByLocalProject')));
+
+      await service.testExtension('setPubRootDirectories', <String, String>{'arg0': 'file://$pubRootTest', 'isolateId': '34'});
+      expect(await service.testExtension('getSelectedWidget', <String, String>{'objectGroup': 'my-group'}), contains('createdByLocalProject'));
+
+      await service.testExtension('setPubRootDirectories', <String, String>{'arg0': '$pubRootTest/different', 'isolateId': '34'});
+      expect(await service.testExtension('getSelectedWidget', <String, String>{'objectGroup': 'my-group'}), isNot(contains('createdByLocalProject')));
+
+      await service.testExtension('setPubRootDirectories', <String, String>{
+        'arg0': '/unrelated/$pubRootTest',
+        'isolateId': '34',
+        'arg1': 'file://$pubRootTest',
+      });
+
+      expect(await service.testExtension('getSelectedWidget', <String, String>{'objectGroup': 'my-group'}), contains('createdByLocalProject'));
+    }, skip: !WidgetInspectorService.instance.isWidgetCreationTracked() || isBrowser); // Test requires --track-widget-creation flag.
+
     testWidgets('ext.flutter.inspector.trackRebuildDirtyWidgets', (WidgetTester tester) async {
       service.rebuildCount = 0;