Fix misdetection of component comments (#52647) (#52744)

Author: MackinnonBuck

src/Components/Web.JS/dist/Release/blazor.server.js

@@ -149,12 +149,13 @@ export function insertLogicalChildBefore(child: Node, parent: LogicalElement, be
 export function insertLogicalChild(child: Node, parent: LogicalElement, childIndex: number): void {
   const childAsLogicalElement = child as unknown as LogicalElement;
 
-  // If the child is a component comment with logical siblings, its siblings also
+  // If the child is a component comment with logical children, its children
   // need to be inserted into the parent node
   let nodeToInsert = child;
-  if (isLogicalElement(child)) {
-    const lastNodeToInsert = findLastDomNodeInRange(childAsLogicalElement);
-    if (lastNodeToInsert !== child) {
+  if (child instanceof Comment) {
+    const existingGranchildren = getLogicalChildrenArray(childAsLogicalElement);
+    if (existingGranchildren?.length > 0) {
+      const lastNodeToInsert = findLastDomNodeInRange(childAsLogicalElement);
       const range = new Range();
       range.setStartBefore(child);
       range.setEndAfter(lastNodeToInsert);

src/Components/Web.JS/dist/Release/blazor.web.js

@@ -316,4 +316,37 @@ public async Task WorksWithVeryBriefStreamingDelays()
             Assert.Matches(new Regex(@"</html><!--[0-9a-f\-]{36}--><blazor-ssr>"), html);
         }
     }
+
+    // https://github.com/dotnet/aspnetcore/issues/52126
+    [Fact]
+    public void CanPerformEnhancedNavigation_AfterStreamingUpdate_WithInteractiveComponentInLayout()
+    {
+        Navigate($"{ServerPathBase}/interactive-in-layout/streaming");
+
+        Browser.Exists(By.Id("done-streaming"));
+        Browser.Equal("True", () => Browser.FindElement(By.Id("is-interactive-counter")).Text);
+        Browser.Click(By.Id("increment-counter"));
+        Browser.Equal("1", () => Browser.FindElement(By.Id("count-counter")).Text);
+
+        Browser.Click(By.LinkText("Non-streaming"));
+        Browser.Exists(By.Id("non-streamed-content"));
+
+        Browser.Click(By.Id("increment-counter"));
+        Browser.Equal("2", () => Browser.FindElement(By.Id("count-counter")).Text);
+
+        AssertLogDoesNotContainCriticalMessages("DOMException");
+    }
+
+    private void AssertLogDoesNotContainCriticalMessages(params string[] messages)
+    {
+        var log = Browser.Manage().Logs.GetLog(LogType.Browser);
+        foreach (var message in messages)
+        {
+            Assert.DoesNotContain(log, entry =>
+            {
+                return entry.Level == LogLevel.Severe
+                && entry.Message.Contains(message);
+            });
+        }
+    }
 }

src/Components/Web.JS/dist/Release/blazor.webview.js

@@ -0,0 +1,9 @@
+@inherits LayoutComponentBase
+
+<NavLink href="interactive-in-layout/streaming">Streaming</NavLink>
+<NavLink href="interactive-in-layout/non-streaming">Non-streaming</NavLink>
+
+@* https://github.com/dotnet/aspnetcore/issues/52126 *@
+<TestContentPackage.Counter IdSuffix="counter" IncrementAmount="1" @rendermode="RenderMode.InteractiveServer" />
+
+@Body

src/Components/Web.JS/src/Rendering/LogicalElements.ts

@@ -0,0 +1,6 @@
+@layout LayoutWithInteractiveComponent
+@page "/interactive-in-layout/non-streaming"
+
+<h3>Non-streaming</h3>
+
+<p id="non-streamed-content">Non-streamed content</p>

src/Components/test/E2ETest/ServerRenderingTests/StreamingRenderingTest.cs

@@ -0,0 +1,20 @@
+@layout LayoutWithInteractiveComponent
+@page "/interactive-in-layout/streaming"
+@attribute [StreamRendering]
+
+<h3>Streaming</h3>
+
+@if (_doneStreaming)
+{
+    <p id="done-streaming">Done streaming!</p>
+}
+
+@code {
+    bool _doneStreaming;
+
+    protected override async Task OnInitializedAsync()
+    {
+        await Task.Delay(200);
+        _doneStreaming = true;
+    }
+}