Add unit tests.

Author: ilonatommy

src/Components/Components/test/NavigationManagerTest.cs

@@ -1,7 +1,10 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+using System.Buffers;
 using System.Diagnostics;
+using System.Net.Http;
+using System.Text;
 using Microsoft.AspNetCore.Components.Routing;
 using Microsoft.AspNetCore.InternalTesting;
 
@@ -868,6 +871,22 @@ async ValueTask HandleLocationChanging(LocationChangingContext context)
         }
     }
 
+    [Fact]
+    public void OnNotFoundSubscriptionIsTriggeredWhenNotFoundCalled()
+    {
+        // Arrange
+        var baseUri = "scheme://host/";
+        var testNavManager = new TestNavigationManager(baseUri);
+        bool notFoundTriggered = false;
+        testNavManager.OnNotFound += (sender, args) => notFoundTriggered = true;
+
+        // Simulate a component triggered NotFound
+        testNavManager.NotFound();
+
+        // Assert
+        Assert.True(notFoundTriggered, "The OnNotFound event was not triggered as expected.");
+    }
+ 
     private class TestNavigationManager : NavigationManager
     {
         public TestNavigationManager()

src/Components/Endpoints/test/EndpointHtmlRendererTest.cs

@@ -46,6 +46,21 @@ public EndpointHtmlRendererTest()
         renderer = GetEndpointHtmlRenderer();
     }
 
+    [Fact]
+    public async Task DoesNotRenderChildAfterRendererStopped()
+    {
+        renderer.SignalRendererToFinishRendering();
+
+        var httpContext = GetHttpContext();
+        var writer = new StringWriter();
+
+        var result = await renderer.PrerenderComponentAsync(httpContext, typeof(SimpleComponent), null, ParameterView.Empty);
+        await renderer.Dispatcher.InvokeAsync(() => result.WriteTo(writer, HtmlEncoder.Default));
+        var content = writer.ToString();
+
+        Assert.DoesNotContain("Hello from SimpleComponent", content);
+    }
+
     [Fact]
     public async Task CanRender_ParameterlessComponent_ClientMode()
     {
@@ -1756,6 +1771,7 @@ private TestEndpointHtmlRenderer GetEndpointHtmlRenderer(IServiceProvider servic
 
     private class TestEndpointHtmlRenderer : EndpointHtmlRenderer
     {
+        private bool _rendererIsStopped = false;
         public TestEndpointHtmlRenderer(IServiceProvider serviceProvider, ILoggerFactory loggerFactory) : base(serviceProvider, loggerFactory)
         {
         }
@@ -1764,6 +1780,20 @@ internal int TestAssignRootComponentId(IComponent component)
         {
             return base.AssignRootComponentId(component);
         }
+        public void SignalRendererToFinishRendering()
+        {
+            // sets a deferred stop on the renderer, which will have an effect after the current batch is completed
+            _rendererIsStopped = true;
+        }
+
+        protected override void ProcessPendingRender()
+        {
+            if (_rendererIsStopped)
+            {
+                return;
+            }
+            base.ProcessPendingRender();
+        }
     }
 
     private HttpContext GetHttpContext(HttpContext context = null)