Sort diagnostics node dependencies so that order is stable (#105319)

* Sort diagnostics node dependencies so that order is stable

* use toDescription

* use toStringShort when possible

* sort InheritedElements

Author: kenzieschmoll

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

@@ -4452,8 +4452,12 @@ abstract class Element extends DiagnosticableTree implements BuildContext {
     properties.add(DiagnosticsProperty<Key>('key', _widget?.key, showName: false, defaultValue: null, level: DiagnosticLevel.hidden));
     _widget?.debugFillProperties(properties);
     properties.add(FlagProperty('dirty', value: dirty, ifTrue: 'dirty'));
-    if (_dependencies != null && _dependencies!.isNotEmpty) {
-      final List<DiagnosticsNode> diagnosticsDependencies = _dependencies!
+    final Set<InheritedElement>? deps = _dependencies;
+    if (deps != null && deps.isNotEmpty) {
+      final List<InheritedElement> sortedDependencies = deps.toList()
+        ..sort((InheritedElement a, InheritedElement b) =>
+            a.toStringShort().compareTo(b.toStringShort()));
+      final List<DiagnosticsNode> diagnosticsDependencies = sortedDependencies
         .map((InheritedElement element) => element.widget.toDiagnosticsNode(style: DiagnosticsTreeStyle.sparse))
         .toList();
       properties.add(DiagnosticsProperty<List<DiagnosticsNode>>('dependencies', diagnosticsDependencies));

packages/flutter/test/widgets/framework_test.dart

@@ -1558,6 +1558,50 @@ void main() {
     expect(builder.properties.any((DiagnosticsNode property) => property.name == 'renderObject' && property.value == null), isTrue);
   });
 
+  testWidgets('debugFillProperties sorts dependencies in alphabetical order', (WidgetTester tester) async {
+    final DiagnosticPropertiesBuilder builder = DiagnosticPropertiesBuilder();
+    final TestRenderObjectElement element = TestRenderObjectElement();
+
+    final _TestInheritedElement focusTraversalOrder =
+    _TestInheritedElement(const FocusTraversalOrder(
+      order: LexicalFocusOrder(''),
+      child: Placeholder(),
+    ));
+    final _TestInheritedElement directionality =
+        _TestInheritedElement(const Directionality(
+      textDirection: TextDirection.ltr,
+      child: Placeholder(),
+    ));
+    final _TestInheritedElement buttonBarTheme =
+        _TestInheritedElement(const ButtonBarTheme(
+        data: ButtonBarThemeData(
+          alignment: MainAxisAlignment.center,
+        ),
+      child: Placeholder(),
+    ));
+
+    // Dependencies are added out of alphabetical order.
+    element
+      ..dependOnInheritedElement(focusTraversalOrder)
+      ..dependOnInheritedElement(directionality)
+      ..dependOnInheritedElement(buttonBarTheme);
+
+    // Dependencies will be sorted by [debugFillProperties].
+    element.debugFillProperties(builder);
+
+    expect(
+      builder.properties.any((DiagnosticsNode property) => property.name == 'dependencies' && property.value != null),
+      isTrue,
+    );
+    final DiagnosticsProperty<List<DiagnosticsNode>> dependenciesProperty =
+        builder.properties.firstWhere((DiagnosticsNode property) => property.name == 'dependencies') as DiagnosticsProperty<List<DiagnosticsNode>>;
+    expect(dependenciesProperty, isNotNull);
+
+    final List<DiagnosticsNode> dependencies = dependenciesProperty.value!;
+    expect(dependencies.length, equals(3));
+    expect(dependencies.toString(), '[ButtonBarTheme, Directionality, FocusTraversalOrder]');
+  });
+
   testWidgets('BuildOwner.globalKeyCount keeps track of in-use global keys', (WidgetTester tester) async {
     final int initialCount = tester.binding.buildOwner!.globalKeyCount;
     final GlobalKey key1 = GlobalKey();