Interactive NotFound tests.

Author: ilonatommy

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

@@ -27,6 +27,17 @@ public RenderingTest(
     public override Task InitializeAsync()
         => InitializeAsync(BrowserFixture.StreamingContext);
 
+    [Theory]
+    [InlineData("server")]
+    [InlineData("webassembly")]
+    public void CanRenderNotFoundInteractive(string renderingMode)
+    {
+        Navigate($"{ServerPathBase}/render-not-found-{renderingMode}");
+
+        var bodyText = Browser.FindElement(By.TagName("body")).Text;
+        Assert.Contains("There's nothing here", bodyText);
+    }
+
     [Fact]
     public void CanRenderLargeComponentsWithServerRenderMode()
     {

src/Components/test/testassets/Components.TestServer/RazorComponents/Pages/Rendering/NotFoundInteractiveServer.razor

@@ -0,0 +1,12 @@
+@page "/render-not-found-server"
+@rendermode RenderMode.InteractiveServer
+@inject NavigationManager NavigationManager
+
+<p id="test-info">Any content</p>
+
+@code{
+    protected override void OnInitialized()
+    {
+        NavigationManager.NotFound();
+    }
+}

src/Components/test/testassets/Components.TestServer/RazorComponents/Pages/Rendering/NotFoundInteractiveWebassembly.razor

@@ -0,0 +1,12 @@
+@page "/render-not-found-webassembly"
+@rendermode RenderMode.InteractiveWebAssembly
+@inject NavigationManager NavigationManager
+
+<p id="test-info">Any content</p>
+
+@code{
+    protected override void OnInitialized()
+    {
+        NavigationManager.NotFound();
+    }
+}