[PropertyEditor] Do not send requests to getEditableArguments for non-Dart files

packages/devtools_app/lib/src/standalone_ui/ide_shared/property_editor/property_editor_controller.dart

@@ -16,7 +16,12 @@ import '../../../shared/utils/utils.dart';
 import 'property_editor_types.dart';
 
 typedef EditableWidgetData =
-    ({List<EditableProperty> properties, String? name, String? documentation});
+    ({
+      List<EditableProperty> properties,
+      String? name,
+      String? documentation,
+      String? fileUri,
+    });
 
 typedef EditArgumentFunction =
     Future<EditArgumentResponse?> Function<T>({
@@ -84,6 +89,15 @@ class PropertyEditorController extends DisposableController
             cursorPosition == _currentCursorPosition) {
           return;
         }
+        if (!textDocument.uriAsString.endsWith('.dart')) {
+          _editableWidgetData.value = (
+            properties: [],
+            name: null,
+            documentation: null,
+            fileUri: textDocument.uriAsString,
+          );
+          return;
+        }
         _editableArgsDebouncer.run(
           () => _updateWithEditableArgs(
             textDocument: textDocument,
@@ -148,6 +162,7 @@ class PropertyEditorController extends DisposableController
       properties: properties,
       name: name,
       documentation: result?.documentation,
+      fileUri: _currentDocument?.uriAsString,
     );
     filterData(activeFilter.value);
     // Register impression.
@@ -180,6 +195,7 @@ class PropertyEditorController extends DisposableController
             editableArgsResult.args.map(argToProperty).nonNulls.toList(),
         name: editableArgsResult.name,
         documentation: editableArgsResult.documentation,
+        fileUri: document?.uriAsString,
       );
     }
     if (document != null) {

packages/devtools_app/lib/src/standalone_ui/ide_shared/property_editor/property_editor_view.dart

@@ -50,8 +50,15 @@ class PropertyEditorView extends StatelessWidget {
           );
         }
 
+        final (:properties, :name, :documentation, :fileUri) =
+            editableWidgetData;
+        if (fileUri != null && !fileUri.endsWith('.dart')) {
+          return const CenteredMessage(
+            message: 'No Dart code found at the current cursor location.',
+          );
+        }
+
         final filteredProperties = values.fourth as List<EditableProperty>;
-        final (:properties, :name, :documentation) = editableWidgetData;
         return Column(
           crossAxisAlignment: CrossAxisAlignment.start,
           children: [

packages/devtools_app/test/standalone_ui/ide_shared/property_editor/property_editor_test.dart

@@ -57,6 +57,7 @@ void main() {
 
   group('on cursor location change', () {
     void Function()? listener;
+    Completer? getEditableArgsCalled;
 
     Future<List<EditableArgument>> waitForEditableArgs() {
       final argsCompleter = Completer<List<EditableArgument>>();
@@ -87,6 +88,7 @@ void main() {
     }
 
     setUp(() {
+      getEditableArgsCalled = Completer<void>();
       for (final MapEntry(key: location, value: result)
           in locationToArgsResult.entries) {
         when(
@@ -95,7 +97,11 @@ void main() {
             textDocument: location.document,
             position: location.position,
           ),
-        ).thenAnswer((realInvocation) => Future.value(result));
+        ).thenAnswer((realInvocation) {
+          getEditableArgsCalled?.complete();
+          getEditableArgsCalled = Completer<void>();
+          return Future.value(result);
+        });
       }
     });
 
@@ -175,6 +181,38 @@ void main() {
         expect(titleValue, equals('Hello world!'));
       });
     });
+
+    testWidgets('verify does not fetch editable arguments for non-Dart files', (
+      tester,
+    ) async {
+      return await tester.runAsync(() async {
+        // Load the property editor.
+        await tester.pumpWidget(wrap(propertyEditor));
+        final getEditableArgsCalledFuture = getEditableArgsCalled!.future;
+
+        // Send an active location changed event.
+        eventController.add(activeLocationChangedEventNotDart);
+
+        // Verify it doesn't trigger a request to getEditableArgs.
+        try {
+          await getEditableArgsCalledFuture.timeout(
+            const Duration(milliseconds: 100),
+          );
+          fail('getEditableArgs was unexpectedly called.');
+        } on TimeoutException catch (e) {
+          expect(e, isA<TimeoutException>());
+        }
+
+        // Verify "No Dart code" message is shown.
+        await tester.pumpAndSettle();
+        expect(
+          find.textContaining(
+            'No Dart code found at the current cursor location.',
+          ),
+          findsOneWidget,
+        );
+      });
+    });
   });
 
   group('inputs for editable arguments', () {
@@ -1020,6 +1058,15 @@ final activeLocationChangedEvent4 = ActiveLocationChangedEvent(
   textDocument: textDocument1,
 );
 
+final notADartDocument = TextDocument(
+  uriAsString: '/my/fake/other.js',
+  version: 1,
+);
+final activeLocationChangedEventNotDart = ActiveLocationChangedEvent(
+  selections: [editorSelection1],
+  textDocument: notADartDocument,
+);
+
 // Widget name and documentation
 const widgetName = 'MyFlutterWidget';