Fix Blazor error logging to telemetry

src/Aspire.Dashboard/Components/Routes.razor

@@ -10,22 +10,20 @@
     return;
 }
 
-<TelemetryErrorBoundary>
-    <CascadingValue Value="@_viewportInformation">
-        <Router AppAssembly="@typeof(App).Assembly">
-            <Found Context="routeData">
-                <!-- AuthorizeRouteView protects pages from being accessed when authorization is required -->
-                <AuthorizeRouteView RouteData="@routeData" DefaultLayout="@typeof(Layout.MainLayout)" />
-            </Found>
-            <NotFound>
-                <PageTitle>@Loc[nameof(Resources.Routes.NotFoundPageTitle)]</PageTitle>
-                <LayoutView Layout="@typeof(Layout.MainLayout)">
-                    <Aspire.Dashboard.Components.Pages.NotFound />
-                </LayoutView>
-            </NotFound>
-        </Router>
-    </CascadingValue>
-</TelemetryErrorBoundary>
+<CascadingValue Value="@_viewportInformation">
+    <Router AppAssembly="@typeof(App).Assembly">
+        <Found Context="routeData">
+            <!-- AuthorizeRouteView protects pages from being accessed when authorization is required -->
+            <AuthorizeRouteView RouteData="@routeData" DefaultLayout="@typeof(Layout.MainLayout)" />
+        </Found>
+        <NotFound>
+            <PageTitle>@Loc[nameof(Resources.Routes.NotFoundPageTitle)]</PageTitle>
+            <LayoutView Layout="@typeof(Layout.MainLayout)">
+                <Aspire.Dashboard.Components.Pages.NotFound />
+            </LayoutView>
+        </NotFound>
+    </Router>
+</CascadingValue>
 
 @code {
     private ViewportInformation? _viewportInformation;

src/Aspire.Dashboard/DashboardWebApplication.cs

@@ -240,6 +240,7 @@ public DashboardWebApplication(
         builder.Services.TryAddScoped<ComponentTelemetryContextProvider>();
         builder.Services.TryAddSingleton<DashboardTelemetryService>();
         builder.Services.TryAddSingleton<IDashboardTelemetrySender, DashboardTelemetrySender>();
+        builder.Services.AddSingleton<ILoggerProvider, TelemetryLoggerProvider>();
 
         // OTLP services.
         builder.Services.AddGrpc();

src/Aspire.Dashboard/Telemetry/TelemetryLoggerProvider.cs

@@ -0,0 +1,73 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace Aspire.Dashboard.Telemetry;
+
+/// <summary>
+/// Log an error to dashboard telemetry when there is an unhandled Blazor error.
+/// </summary>
+public sealed class TelemetryLoggerProvider : ILoggerProvider
+{
+    // Log when an unhandled error is caught by Blazor.
+    // https://github.com/dotnet/aspnetcore/blob/0230498dfccaef6f782a5e37c60ea505081b72bf/src/Components/Server/src/Circuits/CircuitHost.cs#L695
+    public const string CircuitHostLogCategory = "Microsoft.AspNetCore.Components.Server.Circuits.CircuitHost";
+    public static readonly EventId CircuitUnhandledExceptionEventId = new EventId(111, "CircuitUnhandledException");
+
+    private readonly IServiceProvider _serviceProvider;
+
+    public TelemetryLoggerProvider(IServiceProvider serviceProvider)
+    {
+        _serviceProvider = serviceProvider;
+    }
+
+    public ILogger CreateLogger(string categoryName) => new TelemetryLogger(_serviceProvider, categoryName);
+
+    public void Dispose()
+    {
+    }
+
+    private sealed class TelemetryLogger : ILogger
+    {
+        private readonly IServiceProvider _serviceProvider;
+        private readonly bool _isCircuitHostLogger;
+
+        public TelemetryLogger(IServiceProvider serviceProvider, string categoryName)
+        {
+            _serviceProvider = serviceProvider;
+            _isCircuitHostLogger = categoryName == CircuitHostLogCategory;
+        }
+
+        public IDisposable? BeginScope<TState>(TState state) where TState : notnull => null;
+
+        public bool IsEnabled(LogLevel logLevel) => true;
+
+        public void Log<TState>(LogLevel logLevel, EventId eventId, TState state, Exception? exception, Func<TState, Exception?, string> formatter)
+        {
+            if (_isCircuitHostLogger && eventId == CircuitUnhandledExceptionEventId && exception != null)
+            {
+                try
+                {
+                    // Get the telemetry service lazily to avoid a circular reference between resolving telemetry service and logging.
+                    var telemetryService = _serviceProvider.GetRequiredService<DashboardTelemetryService>();
+
+                    telemetryService.PostFault(
+                        TelemetryEventKeys.Error,
+                        $"{exception.GetType().FullName}: {exception.Message}",
+                        FaultSeverity.Critical,
+                        new Dictionary<string, AspireTelemetryProperty>
+                        {
+                            [TelemetryPropertyKeys.ExceptionType] = new AspireTelemetryProperty(exception.GetType().FullName!),
+                            [TelemetryPropertyKeys.ExceptionMessage] = new AspireTelemetryProperty(exception.Message),
+                            [TelemetryPropertyKeys.ExceptionStackTrace] = new AspireTelemetryProperty(exception.StackTrace ?? string.Empty)
+                        }
+                    );
+                }
+                catch
+                {
+                    // We should never throw an error out of logging.
+                    // Logging the error to telemetry shouldn't throw. But, for extra safety, send error to telemetry is inside a try/catch.
+                }
+            }
+        }
+    }
+}

tests/Aspire.Dashboard.Tests/Integration/StartupTests.cs

@@ -6,6 +6,7 @@
 using System.Text.Json.Nodes;
 using Aspire.Dashboard.Configuration;
 using Aspire.Dashboard.Otlp.Http;
+using Aspire.Dashboard.Telemetry;
 using Aspire.Hosting;
 using Aspire.Tests.Shared.Telemetry;
 using Google.Protobuf;
@@ -15,6 +16,7 @@
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Logging.Abstractions;
+using Microsoft.Extensions.Logging.Console;
 using Microsoft.Extensions.Logging.Testing;
 using Microsoft.Extensions.Options;
 using Microsoft.Net.Http.Headers;
@@ -765,6 +767,20 @@ public async Task Configuration_DisableResourceGraph_EnsureValueSetOnOptions(boo
         // Assert
         Assert.Equal(value, app.DashboardOptionsMonitor.CurrentValue.UI.DisableResourceGraph);
     }
+    [Fact]
+    public async Task ServiceProvider_AppCreated_LoggerProvidersRegistered()
+    {
+        // Arrange
+        await using var app = IntegrationTestHelpers.CreateDashboardWebApplication(testOutputHelper);
+
+        // Act
+        var loggerProviders = app.Services.GetServices<ILoggerProvider>();
+        var loggerProviderTypes = loggerProviders.Select(p => p.GetType()).ToList();
+
+        // Assert
+        Assert.Contains(typeof(TelemetryLoggerProvider), loggerProviderTypes);
+        Assert.Contains(typeof(ConsoleLoggerProvider), loggerProviderTypes);
+    }
 
     private static void AssertIPv4OrIPv6Endpoint(Func<EndpointInfo> endPointAccessor)
     {

tests/Aspire.Dashboard.Tests/Telemetry/TelemetryLoggerProviderTests.cs

@@ -0,0 +1,48 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using Aspire.Dashboard.Telemetry;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Logging;
+using Xunit;
+
+namespace Aspire.Dashboard.Tests.Telemetry;
+
+public class TelemetryLoggerProviderTests
+{
+    [Fact]
+    public async Task Log_DifferentCategoryAndEventIds_WriteTelemetryForBlazorUnhandedErrorAsync()
+    {
+        // Arrange
+        var telemetrySender = new TestDashboardTelemetrySender { IsTelemetryEnabled = true };
+        await telemetrySender.TryStartTelemetrySessionAsync();
+
+        var serviceProvider = new ServiceCollection()
+            .AddSingleton<DashboardTelemetryService>()
+            .AddSingleton<IDashboardTelemetrySender>(telemetrySender)
+            .AddLogging()
+            .AddSingleton<ILoggerProvider, TelemetryLoggerProvider>()
+            .BuildServiceProvider();
+
+        var loggerProvider = serviceProvider.GetRequiredService<ILoggerFactory>();
+
+        // Act & assert 1
+        var testLogger = loggerProvider.CreateLogger("testLogger");
+        testLogger.Log(LogLevel.Error, TelemetryLoggerProvider.CircuitUnhandledExceptionEventId, "Test message");
+        Assert.False(telemetrySender.ContextChannel.Reader.TryPeek(out _));
+
+        // Act & assert 2
+        var circuitHostLogger = loggerProvider.CreateLogger(TelemetryLoggerProvider.CircuitHostLogCategory);
+        circuitHostLogger.LogInformation("Test log message");
+        Assert.False(telemetrySender.ContextChannel.Reader.TryPeek(out _));
+
+        // Act & assert 3
+        circuitHostLogger.Log(LogLevel.Error, TelemetryLoggerProvider.CircuitUnhandledExceptionEventId, "Test message");
+        Assert.False(telemetrySender.ContextChannel.Reader.TryPeek(out _));
+
+        // Act & assert 4
+        circuitHostLogger.Log(LogLevel.Error, TelemetryLoggerProvider.CircuitUnhandledExceptionEventId, new InvalidOperationException("Exception message"), "Test message");
+        Assert.True(telemetrySender.ContextChannel.Reader.TryPeek(out var context));
+        Assert.Equal("/telemetry/fault - $aspire/dashboard/error", context.Name);
+    }
+}