test: add computeDryBaseline tests for custom RenderBox subclasses

These tests verify that getDryBaseline works correctly on all custom
render objects. Four tests currently fail because the render objects
that extend RenderBox directly do not implement computeDryBaseline,
which is required in Flutter 3.32+.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: daohoangson

packages/core/test/compute_dry_baseline_test.dart

@@ -0,0 +1,182 @@
+import 'package:flutter/material.dart';
+import 'package:flutter/rendering.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:flutter_widget_from_html_core/flutter_widget_from_html_core.dart';
+
+import '_.dart';
+
+void main() {
+  group('computeDryBaseline', () {
+    testWidgets('HtmlListItem', (tester) async {
+      final key = GlobalKey();
+      await tester.pumpWidget(
+        MaterialApp(
+          home: Scaffold(
+            body: HtmlListItem(
+              key: key,
+              marker: const Text('1.'),
+              textDirection: TextDirection.ltr,
+              child: const Text('Hello'),
+            ),
+          ),
+        ),
+      );
+      await tester.pumpAndSettle();
+
+      final renderBox = key.renderBox;
+      final baseline = renderBox.getDryBaseline(
+        renderBox.constraints,
+        TextBaseline.alphabetic,
+      );
+      expect(baseline, isNotNull);
+    });
+
+    testWidgets('HtmlListMarker', (tester) async {
+      final key = GlobalKey();
+      await tester.pumpWidget(
+        MaterialApp(
+          home: Scaffold(
+            body: HtmlListItem(
+              marker: HtmlListMarker(
+                key: key,
+                markerType: HtmlListMarkerType.disc,
+                textStyle: const TextStyle(fontSize: 14),
+              ),
+              textDirection: TextDirection.ltr,
+              child: const Text('Hello'),
+            ),
+          ),
+        ),
+      );
+      await tester.pumpAndSettle();
+
+      final renderBox = key.renderBox;
+      final baseline = renderBox.getDryBaseline(
+        renderBox.constraints,
+        TextBaseline.alphabetic,
+      );
+      expect(baseline, isNotNull);
+    });
+
+    testWidgets('HtmlRuby', (tester) async {
+      final key = GlobalKey();
+      await tester.pumpWidget(
+        MaterialApp(
+          home: Scaffold(
+            body: HtmlRuby(
+              key: key,
+              ruby: const Text('漢'),
+              rt: const Text('かん'),
+            ),
+          ),
+        ),
+      );
+      await tester.pumpAndSettle();
+
+      final renderBox = key.renderBox;
+      final baseline = renderBox.getDryBaseline(
+        renderBox.constraints,
+        TextBaseline.alphabetic,
+      );
+      expect(baseline, isNotNull);
+    });
+
+    testWidgets('HtmlTable', (tester) async {
+      final key = GlobalKey();
+      await tester.pumpWidget(
+        HtmlTable(
+          key: key,
+          children: const [
+            HtmlTableCell(
+              columnStart: 0,
+              rowStart: 0,
+              child: Text('Cell'),
+            ),
+          ],
+        ),
+      );
+      await tester.pumpAndSettle();
+
+      final renderBox = key.renderBox;
+      final baseline = renderBox.getDryBaseline(
+        const BoxConstraints(maxWidth: 100, maxHeight: 100),
+        TextBaseline.alphabetic,
+      );
+      expect(baseline, isNotNull);
+    });
+
+    testWidgets('HorizontalMargin', (tester) async {
+      final key = GlobalKey();
+      await tester.pumpWidget(
+        MaterialApp(
+          home: Scaffold(
+            body: SizedBox(
+              width: 100,
+              child: HorizontalMargin(
+                key: key,
+                left: 10,
+                right: 10,
+                child: const Text('Hello'),
+              ),
+            ),
+          ),
+        ),
+      );
+      await tester.pumpAndSettle();
+
+      final renderBox = key.renderBox;
+      final baseline = renderBox.getDryBaseline(
+        renderBox.constraints,
+        TextBaseline.alphabetic,
+      );
+      expect(baseline, isNotNull);
+    });
+
+    testWidgets('CssSizing', (tester) async {
+      final key = GlobalKey();
+      await tester.pumpWidget(
+        MaterialApp(
+          home: Scaffold(
+            body: CssSizing(
+              key: key,
+              child: const Text('Hello'),
+            ),
+          ),
+        ),
+      );
+      await tester.pumpAndSettle();
+
+      final renderBox = key.renderBox;
+      final baseline = renderBox.getDryBaseline(
+        renderBox.constraints,
+        TextBaseline.alphabetic,
+      );
+      expect(baseline, isNotNull);
+    });
+
+    testWidgets('ValignBaseline', (tester) async {
+      final key = GlobalKey();
+      await tester.pumpWidget(
+        MaterialApp(
+          home: Scaffold(
+            body: ValignBaselineContainer(
+              child: ValignBaseline(
+                key: key,
+                index: 0,
+                child: const Text('Hello'),
+              ),
+            ),
+          ),
+        ),
+      );
+      await tester.pumpAndSettle();
+
+      final renderBox = key.renderBox;
+      final baseline = renderBox.getDryBaseline(
+        renderBox.constraints,
+        TextBaseline.alphabetic,
+      );
+      expect(baseline, isNotNull);
+    });
+  });
+}