Fix: Return shadow host for text node in shadow root in SerializedAXNode.ElementHandle (#15451)

lib/PuppeteerSharp.Tests/AccessibilityTests/RootOptionTests.cs

@@ -1,3 +1,4 @@
+using System.Linq;
 using System.Threading.Tasks;
 using NUnit.Framework;
 using PuppeteerSharp.Nunit;
@@ -172,6 +173,32 @@ public async Task ShouldGetTheParentElementHandleFromATextNodeAccessibilityNode(
             Assert.That(textNodeInnerHtml, Is.EqualTo("<b>Hello, </b> world!"));
         }
 
+        [Test, PuppeteerTest("accessibility.spec", "elementHandle()", "should get the shadow host ElementHandle from a text node in a shadow root")]
+        public async Task ShouldGetTheShadowHostElementHandleFromATextNodeInAShadowRoot()
+        {
+            await Page.SetContentAsync("<div id=\"host\"></div>");
+            await Page.EvaluateExpressionAsync(@"
+                document
+                    .querySelector('#host')
+                    .attachShadow({mode: 'open'}).textContent = 'Shadow text';
+            ");
+            var host = await Page.QuerySelectorAsync("#host");
+
+            var snapshot = await Page.Accessibility.SnapshotAsync(new AccessibilitySnapshotOptions
+            {
+                Root = host,
+                InterestingOnly = false,
+            });
+            var textNode = snapshot.Children.First(child => child.Name == "Shadow text");
+            Assert.That(textNode.Role, Is.EqualTo("StaticText"));
+
+            var textNodeHandle = await textNode.ElementHandleAsync();
+            Assert.That(textNodeHandle, Is.Not.Null);
+            Assert.That(
+                await textNodeHandle.EvaluateFunctionAsync<string>("element => element.id"),
+                Is.EqualTo("host"));
+        }
+
         [Test, PuppeteerTest("accessibility.spec", "root option", "should work with nested button inside h1 with interestingOnly:true")]
         public async Task ShouldWorkWithNestedButtonInsideH1WithInterestingOnlyTrue()
         {

lib/PuppeteerSharp/PageAccessibility/AXNode.cs

@@ -270,8 +270,14 @@ internal SerializedAXNode Serialize()
 
                         // Since Text nodes are not elements, we want to
                         // return a handle to the parent element for them.
-                        return await ((ElementHandle)handle).EvaluateFunctionHandleAsync(
-                            "node => node.nodeType === Node.TEXT_NODE ? node.parentElement : node").ConfigureAwait(false) as IElementHandle;
+                        // A text node placed directly in a shadow root has no parent
+                        // element, so fall back to the shadow host.
+                        return await ((ElementHandle)handle).EvaluateFunctionHandleAsync(@"node => {
+                            if (node.nodeType !== Node.TEXT_NODE) {
+                                return node;
+                            }
+                            return node.parentElement ?? node.parentNode?.host ?? null;
+                        }").ConfigureAwait(false) as IElementHandle;
                     }
                 : null,
                 Role = _role,