Accept Diagnosticable as input in inspector API. (#128962)

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

@@ -1762,7 +1762,7 @@ mixin WidgetInspectorService {
 
   DiagnosticsNode? _idToDiagnosticsNode(String? diagnosticsOrDiagnosticableId) {
     // TODO(polina-c): start always assuming Diagnosticable, when DevTools stops sending DiagnosticsNode to
-    // getChildrenSummaryTree and getProperties.
+    // APIs that invoke this method.
     // https://github.com/flutter/devtools/issues/3951
     final Object? theObject = toObject(diagnosticsOrDiagnosticableId);
     if (theObject is DiagnosticsNode) {
@@ -1788,17 +1788,17 @@ mixin WidgetInspectorService {
   }
 
   /// Returns a JSON representation of the children of the [DiagnosticsNode]
-  /// object that `diagnosticsNodeId` references providing information needed
+  /// object that [diagnosticsOrDiagnosticableId] references providing information needed
   /// for the details subtree view.
   ///
   /// The details subtree shows properties inline and includes all children
   /// rather than a filtered set of important children.
-  String getChildrenDetailsSubtree(String diagnosticsNodeId, String groupName) {
+  String getChildrenDetailsSubtree(String diagnosticsOrDiagnosticableId, String groupName) {
-    return _safeJsonEncode(_getChildrenDetailsSubtree(diagnosticsNodeId, groupName));
+    return _safeJsonEncode(_getChildrenDetailsSubtree(diagnosticsOrDiagnosticableId, groupName));
   }
 
-  List<Object> _getChildrenDetailsSubtree(String? diagnosticsNodeId, String groupName) {
+  List<Object> _getChildrenDetailsSubtree(String? diagnosticsOrDiagnosticableId, String groupName) {
-    final DiagnosticsNode? node = toObject(diagnosticsNodeId) as DiagnosticsNode?;
+    final DiagnosticsNode? node = _idToDiagnosticsNode(diagnosticsOrDiagnosticableId);
     // With this value of minDepth we only expand one extra level of important nodes.
     final InspectorSerializationDelegate delegate = InspectorSerializationDelegate(groupName: groupName, includeProperties: true, service: this);
     return _nodesToJson(node == null ? const <DiagnosticsNode>[] : _getChildrenFiltered(node, delegate), delegate, parent: node);
@@ -1910,19 +1910,19 @@ mixin WidgetInspectorService {
   ///  * [getChildrenDetailsSubtree], a method to get children of a node
   ///    in the details subtree.
   String getDetailsSubtree(
-    String id,
+    String diagnosticsOrDiagnosticableId,
     String groupName, {
     int subtreeDepth = 2,
   }) {
-    return _safeJsonEncode(_getDetailsSubtree( id, groupName, subtreeDepth));
+    return _safeJsonEncode(_getDetailsSubtree(diagnosticsOrDiagnosticableId, groupName, subtreeDepth));
   }
 
   Map<String, Object?>? _getDetailsSubtree(
-    String? id,
+    String? diagnosticsOrDiagnosticableId,
     String? groupName,
     int subtreeDepth,
   ) {
-    final DiagnosticsNode? root = toObject(id) as DiagnosticsNode?;
+    final DiagnosticsNode? root = _idToDiagnosticsNode(diagnosticsOrDiagnosticableId);
     if (root == null) {
       return null;
     }
@@ -1942,6 +1942,8 @@ mixin WidgetInspectorService {
   /// If the currently selected [Element] is identical to the [Element]
   /// referenced by `previousSelectionId` then the previous [DiagnosticsNode] is
   /// reused.
+  // TODO(polina-c): delete [previousSelectionId] when it is not used in DevTools
+  // https://github.com/flutter/devtools/issues/3951
   @protected
   String getSelectedWidget(String? previousSelectionId, String groupName) {
     return _safeJsonEncode(_getSelectedWidget(previousSelectionId, groupName));
@@ -2020,18 +2022,18 @@ mixin WidgetInspectorService {
   Future<Map<String, Object?>> _getLayoutExplorerNode(
     Map<String, String> parameters,
   ) {
-    final String? id = parameters['id'];
+    final String? diagnosticsOrDiagnosticableId = parameters['id'];
     final int subtreeDepth = int.parse(parameters['subtreeDepth']!);
     final String? groupName = parameters['groupName'];
     Map<String, dynamic>? result = <String, dynamic>{};
-    final Object? root = toObject(id);
+    final DiagnosticsNode? root = _idToDiagnosticsNode(diagnosticsOrDiagnosticableId);
     if (root == null) {
       return Future<Map<String, dynamic>>.value(<String, dynamic>{
         'result': result,
       });
     }
     result = _nodeToJson(
-      root as DiagnosticsNode,
+      root,
       InspectorSerializationDelegate(
         groupName: groupName,
         summaryTree: true,
@@ -2232,6 +2234,8 @@ mixin WidgetInspectorService {
   /// If the currently selected [Element] is identical to the [Element]
   /// referenced by `previousSelectionId` then the previous [DiagnosticsNode] is
   /// reused.
+  // TODO(polina-c): delete paramater [previousSelectionId] when it is not used in DevTools
+  // https://github.com/flutter/devtools/issues/3951
   String getSelectedSummaryWidget(String previousSelectionId, String groupName) {
     return _safeJsonEncode(_getSelectedSummaryWidget(previousSelectionId, groupName));
   }

packages/flutter/test/widgets/widget_inspector_test.dart

@@ -900,6 +900,8 @@ class _TestWidgetInspectorService extends TestWidgetInspectorService {
     });
 
     test('WidgetInspectorService getProperties for $DiagnosticsNode', () {
+      // TODO(polina-c): delete this test once getChildrenDetailsSubtree stops accepting DiagnosticsNode.
+      // https://github.com/flutter/devtools/issues/3951
       final DiagnosticsNode diagnostic = const Text('a', textDirection: TextDirection.ltr).toDiagnosticsNode();
       const String group = 'group';
       service.disposeAllGroups();
@@ -2124,6 +2126,8 @@ class _TestWidgetInspectorService extends TestWidgetInspectorService {
     });
 
     test('ext.flutter.inspector.getProperties for $DiagnosticsNode', () async {
+      // TODO(polina-c): delete this test once getChildrenDetailsSubtree stops accepting DiagnosticsNode.
+      // https://github.com/flutter/devtools/issues/3951
       final DiagnosticsNode diagnostic = const Text('a', textDirection: TextDirection.ltr).toDiagnosticsNode();
       const String group = 'group';
       final String id = service.toId(diagnostic, group)!;
@@ -5090,7 +5094,9 @@ class _TestWidgetInspectorService extends TestWidgetInspectorService {
       expect(box2.localToGlobal(Offset.zero), equals(position2));
     });
 
-    testWidgets('getChildrenDetailsSubtree', (WidgetTester tester) async {
+    testWidgets('getChildrenDetailsSubtree with $DiagnosticsNode', (WidgetTester tester) async {
+      // TODO(polina-c): delete this test once getChildrenDetailsSubtree stops accepting DiagnosticsNode.
+      // https://github.com/flutter/devtools/issues/3951
       await tester.pumpWidget(
         MaterialApp(
           title: 'Hello, World',
@@ -5150,6 +5156,66 @@ class _TestWidgetInspectorService extends TestWidgetInspectorService {
       expect(appBars.single, isNot(contains('children')));
     }, skip: !WidgetInspectorService.instance.isWidgetCreationTracked()); // [intended] Test requires --track-widget-creation flag.
 
+    testWidgets('getChildrenDetailsSubtree with $Diagnosticable', (WidgetTester tester) async {
+      await tester.pumpWidget(
+        MaterialApp(
+          title: 'Hello, World',
+          theme: ThemeData(
+            primarySwatch: Colors.blue,
+          ),
+          home: Scaffold(
+            appBar: AppBar(
+              title: const Text('Hello, World'),
+            ),
+            body: const Center(
+              child: Text('Hello, World!'),
+            ),
+          ),
+        ),
+      );
+      service.setSelection(find.text('Hello, World!').evaluate().first, 'my-group');
+
+      // Figure out the pubRootDirectory
+      final Map<String, Object?> jsonObject = (await service.testExtension(
+        WidgetInspectorServiceExtensions.getSelectedWidget.name,
+        <String, String>{'objectGroup': 'my-group'},
+      ))! as Map<String, Object?>;
+      final Map<String, Object?> creationLocation = jsonObject['creationLocation']! as Map<String, Object?>;
+      expect(creationLocation, isNotNull);
+      final String file = creationLocation['file']! as String;
+      expect(file, endsWith('widget_inspector_test.dart'));
+      final List<String> segments = Uri.parse(file).pathSegments;
+      // Strip a couple subdirectories away to generate a plausible pub rootdirectory.
+      final String pubRootTest = '/${segments.take(segments.length - 2).join('/')}';
+      service.resetPubRootDirectories();
+      service.addPubRootDirectories(<String>[pubRootTest]);
+
+      final String summary = service.getRootWidgetSummaryTree('foo1');
+      // ignore: avoid_dynamic_calls
+      final List<Object?> childrenOfRoot = json.decode(summary)['children'] as List<Object?>;
+      final List<Object?> childrenOfMaterialApp = (childrenOfRoot.first! as Map<String, Object?>)['children']! as List<Object?>;
+      final Map<String, Object?> scaffold = childrenOfMaterialApp.first! as Map<String, Object?>;
+      expect(scaffold['description'], 'Scaffold');
+      final String objectId = scaffold['valueId']! as String;
+      final String details = service.getDetailsSubtree(objectId, 'foo2');
+      // ignore: avoid_dynamic_calls
+      final List<Object?> detailedChildren = json.decode(details)['children'] as List<Object?>;
+
+      final List<Map<String, Object?>> appBars = <Map<String, Object?>>[];
+      void visitChildren(List<Object?> children) {
+        for (final Map<String, Object?> child in children.cast<Map<String, Object?>>()) {
+          if (child['description'] == 'AppBar') {
+            appBars.add(child);
+          }
+          if (child.containsKey('children')) {
+            visitChildren(child['children']! as List<Object?>);
+          }
+        }
+      }
+      visitChildren(detailedChildren);
+      expect(appBars.single, isNot(contains('children')));
+    }, skip: !WidgetInspectorService.instance.isWidgetCreationTracked()); // [intended] Test requires --track-widget-creation flag.
+
     testWidgets('InspectorSerializationDelegate addAdditionalPropertiesCallback', (WidgetTester tester) async {
       await tester.pumpWidget(
         MaterialApp(