Revert "Disconnect circuit on 'beforeunload' event"

src/Components/Web.JS/src/Boot.Server.ts

@@ -67,7 +67,8 @@ async function boot(userOptions?: Partial<CircuitStartOptions>): Promise<void> {
     }
   };
 
-  window.addEventListener('beforeunload', cleanup, { capture: false, once: true });
+  window['Blazor'].disconnect = cleanup;
+
   window.addEventListener('unload', cleanup, { capture: false, once: true });
 
   window['Blazor'].reconnect = reconnect;

src/Components/test/E2ETest/ServerExecutionTests/CircuitGracefulTerminationTests.cs

@@ -44,8 +44,8 @@ public override async Task InitializeAsync()
         protected override void InitializeAsyncCore()
         {
             Navigate(ServerPathBase, noReload: false);
-            Browser.MountTestComponent<CounterComponent>();
-            Browser.Equal("Current count: 0", () => Browser.FindElement(By.TagName("p")).Text);
+            Browser.MountTestComponent<GracefulTermination>();
+            Browser.Equal("Graceful Termination", () => Browser.FindElement(By.TagName("h1")).Text);
 
             GracefulDisconnectCompletionSource = new TaskCompletionSource<object>(TaskCreationOptions.RunContinuationsAsynchronously);
             Sink = _serverFixture.Host.Services.GetRequiredService<TestSink>();
@@ -91,6 +91,45 @@ public async Task ClosingTheBrowserWindow_GracefullyDisconnects_WhenNavigatingAw
             Assert.Contains((Extensions.Logging.LogLevel.Debug, "CircuitDisconnectedPermanently"), Messages);
         }
 
+        [Fact]
+        public async Task NavigatingToProtocolLink_DoesNotGracefullyDisconnect_TheCurrentCircuit()
+        {
+            // Arrange & Act
+            var element = Browser.FindElement(By.Id("mailto-link"));
+            element.Click();
+            await Task.WhenAny(Task.Delay(10000), GracefulDisconnectCompletionSource.Task);
+
+            // Assert
+            Assert.DoesNotContain((Extensions.Logging.LogLevel.Debug, "CircuitTerminatedGracefully"), Messages);
+            Assert.DoesNotContain((Extensions.Logging.LogLevel.Debug, "CircuitDisconnectedPermanently"), Messages);
+        }
+
+        [Fact]
+        public async Task DownloadAction_DoesNotGracefullyDisconnect_TheCurrentCircuit()
+        {
+            // Arrange & Act
+            var element = Browser.FindElement(By.Id("download-link"));
+            element.Click();
+            await Task.WhenAny(Task.Delay(10000), GracefulDisconnectCompletionSource.Task);
+
+            // Assert
+            Assert.DoesNotContain((Extensions.Logging.LogLevel.Debug, "CircuitTerminatedGracefully"), Messages);
+            Assert.DoesNotContain((Extensions.Logging.LogLevel.Debug, "CircuitDisconnectedPermanently"), Messages);
+        }
+
+        [Fact]
+        public async Task DownloadHref_DoesNotGracefullyDisconnect_TheCurrentCircuit()
+        {
+            // Arrange & Act
+            var element = Browser.FindElement(By.Id("download-href"));
+            element.Click();
+            await Task.WhenAny(Task.Delay(10000), GracefulDisconnectCompletionSource.Task);
+
+            // Assert
+            Assert.DoesNotContain((Extensions.Logging.LogLevel.Debug, "CircuitTerminatedGracefully"), Messages);
+            Assert.DoesNotContain((Extensions.Logging.LogLevel.Debug, "CircuitDisconnectedPermanently"), Messages);
+        }
+
         private void Log(WriteContext wc)
         {
             if ((Extensions.Logging.LogLevel.Debug, "CircuitTerminatedGracefully") == (wc.LogLevel, wc.EventId.Name))

src/Components/test/testassets/BasicTestApp/GracefulTermination.razor

@@ -0,0 +1,14 @@
+@inject NavigationManager navigationManager
+
+<h1>Graceful Termination</h1>
+
+<a href="mailto:[email protected]" id="mailto-link">Send Email</a>
+<a href="download" download id="download-href">Download Link</a>
+<button @onclick="DownloadFile" id="download-link">Download File</button>
+
+@code {
+    private void DownloadFile()
+    {
+        navigationManager.NavigateTo("/subdir/download", true);
+    }
+}

src/Components/test/testassets/BasicTestApp/Index.razor

@@ -40,6 +40,7 @@
         <option value="BasicTestApp.FormsTest.InputFileComponent">Input file</option>
         <option value="BasicTestApp.NavigateOnSubmit">Navigate to submit</option>
         <option value="BasicTestApp.GlobalizationBindCases">Globalization Bind Cases</option>
+        <option value="BasicTestApp.GracefulTermination">Graceful Termination</option>
         <option value="BasicTestApp.HierarchicalImportsTest.Subdir.ComponentUsingImports">Imports statement</option>
         <option value="BasicTestApp.HtmlBlockChildContent">ChildContent HTML Block</option>
         <option value="BasicTestApp.HtmlEncodedChildContent">ChildContent HTML Encoded Block</option>

src/Components/test/testassets/TestServer/Controllers/DownloadController.cs

@@ -0,0 +1,22 @@
+using System;
+using System.IO;
+using System.Text;
+using Microsoft.AspNetCore.Mvc;
+
+namespace Components.TestServer.Controllers
+{
+    public class DownloadController : Controller
+    {
+
+        [HttpGet("~/download")]
+        public FileStreamResult Download()
+        {
+            var buffer = Encoding.UTF8.GetBytes("The quick brown fox jumped over the lazy dog.");
+            var stream = new MemoryStream(buffer);
+
+            var result = new FileStreamResult(stream, "text/plain");
+            result.FileDownloadName = "test.txt";
+            return result;
+        }
+    }
+}

src/Components/test/testassets/TestServer/ServerStartup.cs

@@ -39,6 +39,7 @@ public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
                 app.UseEndpoints(endpoints =>
                 {
                     endpoints.MapBlazorHub();
+                    endpoints.MapControllerRoute("mvc", "{controller}/{action}");
                     endpoints.MapFallbackToPage("/_ServerHost");
                 });
             });