From 19654f30df0fa1f145f48d2e72fd148fd16b16c4 Mon Sep 17 00:00:00 2001
From: David Wengier <david.wengier@microsoft.com>
Date: Tue, 20 Feb 2024 11:06:18 +1100
Subject: [PATCH 1/6] Create an export provider for services to discover other
 services

---
 .../RazorServiceFactoryBase.ExportProvider.cs | 30 +++++++++++++++++++
 .../RazorServiceFactoryBase.cs                | 10 +++++--
 .../RemoteTagHelperDeltaProvider.cs           |  2 ++
 .../RemoteTagHelperProviderService.cs         |  6 ++--
 .../RemoteTagHelperProviderServiceFactory.cs  |  5 ++--
 5 files changed, 46 insertions(+), 7 deletions(-)
 create mode 100644 src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RazorServiceFactoryBase.ExportProvider.cs

diff --git a/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RazorServiceFactoryBase.ExportProvider.cs b/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RazorServiceFactoryBase.ExportProvider.cs
new file mode 100644
index 00000000000..a89afc88009
--- /dev/null
+++ b/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RazorServiceFactoryBase.ExportProvider.cs
@@ -0,0 +1,30 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the MIT license. See License.txt in the project root for license information.
+
+using System.Collections.Immutable;
+using System.Reflection;
+using System.Threading.Tasks;
+using Microsoft.VisualStudio.Composition;
+
+namespace Microsoft.CodeAnalysis.Remote.Razor;
+
+internal abstract partial class RazorServiceFactoryBase<TService>
+{
+    internal static readonly ImmutableArray<Assembly> RemoteHostAssemblies = [typeof(RazorServiceFactoryBase<TService>).Assembly];
+
+    private static readonly ExportProvider _exportProvider = CreateExportProvider();
+
+    // Inspired by https://github.com/dotnet/roslyn/blob/25aa74d725e801b8232dbb3e5abcda0fa72da8c5/src/Workspaces/Remote/ServiceHub/Host/RemoteWorkspaceManager.cs#L77
+    private static ExportProvider CreateExportProvider()
+    {
+        var resolver = Resolver.DefaultInstance;
+        var discovery = new AttributedPartDiscovery(resolver, isNonPublicSupported: true); // MEFv2 only
+        var parts = Task.Run(async () => await discovery.CreatePartsAsync(RemoteHostAssemblies).ConfigureAwait(false)).GetAwaiter().GetResult();
+        var catalog = ComposableCatalog.Create(resolver).AddParts(parts);
+
+        var configuration = CompositionConfiguration.Create(catalog);
+        var runtimeComposition = RuntimeComposition.CreateRuntimeComposition(configuration);
+        var exportProviderFactory = runtimeComposition.CreateExportProviderFactory();
+        return exportProviderFactory.CreateExportProvider();
+    }
+}
diff --git a/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RazorServiceFactoryBase.cs b/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RazorServiceFactoryBase.cs
index 59d8b07d3d2..08d6b88c01e 100644
--- a/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RazorServiceFactoryBase.cs
+++ b/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RazorServiceFactoryBase.cs
@@ -9,6 +9,7 @@
 using Microsoft.CodeAnalysis.ExternalAccess.Razor;
 using Microsoft.ServiceHub.Framework;
 using Microsoft.ServiceHub.Framework.Services;
+using Microsoft.VisualStudio.Composition;
 using Nerdbank.Streams;
 
 namespace Microsoft.CodeAnalysis.Remote.Razor;
@@ -19,7 +20,7 @@ namespace Microsoft.CodeAnalysis.Remote.Razor;
 /// <remarks>
 /// Implementors of <see cref="IServiceHubServiceFactory" /> (and thus this class) MUST provide a parameterless constructor or ServiceHub will fail to construct them.
 /// </remarks>
-internal abstract class RazorServiceFactoryBase<TService> : IServiceHubServiceFactory where TService : class
+internal abstract partial class RazorServiceFactoryBase<TService> : IServiceHubServiceFactory where TService : class
 {
     private readonly RazorServiceDescriptorsWrapper _razorServiceDescriptors;
     private ITelemetryReporter? _telemetryReporter;
@@ -55,7 +56,10 @@ internal TService Create(IDuplexPipe pipe, IServiceBroker serviceBroker)
         var descriptor = _razorServiceDescriptors.GetDescriptorForServiceFactory(typeof(TService));
         var serverConnection = descriptor.ConstructRpcConnection(pipe);
 
-        var service = CreateService(serviceBroker, _telemetryReporter ?? NoOpTelemetryReporter.Instance);
+        var service = CreateService(serviceBroker,
+            // TODO: This seems to always be null. Suspect this was intended to be something different.
+            _telemetryReporter ?? NoOpTelemetryReporter.Instance,
+            _exportProvider);
 
         serverConnection.AddLocalRpcTarget(service);
         serverConnection.StartListening();
@@ -63,5 +67,5 @@ internal TService Create(IDuplexPipe pipe, IServiceBroker serviceBroker)
         return service;
     }
 
-    protected abstract TService CreateService(IServiceBroker serviceBroker, ITelemetryReporter telemetryReporter);
+    protected abstract TService CreateService(IServiceBroker serviceBroker, ITelemetryReporter telemetryReporter, ExportProvider exportProvider);
 }
diff --git a/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RemoteTagHelperDeltaProvider.cs b/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RemoteTagHelperDeltaProvider.cs
index 936d5ce6f49..8a00a91192d 100644
--- a/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RemoteTagHelperDeltaProvider.cs
+++ b/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RemoteTagHelperDeltaProvider.cs
@@ -2,11 +2,13 @@
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
 using System.Collections.Immutable;
+using System.Composition;
 using Microsoft.AspNetCore.Razor.Serialization;
 using Microsoft.AspNetCore.Razor.Utilities;
 
 namespace Microsoft.CodeAnalysis.Remote.Razor;
 
+[Export(typeof(RemoteTagHelperDeltaProvider)), Shared]
 internal class RemoteTagHelperDeltaProvider
 {
     private readonly TagHelperResultCache _resultCache = new();
diff --git a/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RemoteTagHelperProviderService.cs b/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RemoteTagHelperProviderService.cs
index 6cceaff9096..0fa723e3e4b 100644
--- a/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RemoteTagHelperProviderService.cs
+++ b/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RemoteTagHelperProviderService.cs
@@ -4,6 +4,7 @@
 using System.Collections.Immutable;
 using System.Threading;
 using System.Threading.Tasks;
+using Microsoft.AspNetCore.Razor;
 using Microsoft.AspNetCore.Razor.Language;
 using Microsoft.AspNetCore.Razor.PooledObjects;
 using Microsoft.AspNetCore.Razor.Serialization;
@@ -12,6 +13,7 @@
 using Microsoft.CodeAnalysis.ExternalAccess.Razor;
 using Microsoft.CodeAnalysis.ExternalAccess.Razor.Api;
 using Microsoft.ServiceHub.Framework;
+using Microsoft.VisualStudio.Composition;
 
 namespace Microsoft.CodeAnalysis.Remote.Razor;
 
@@ -20,11 +22,11 @@ internal sealed class RemoteTagHelperProviderService : RazorServiceBase, IRemote
     private readonly RemoteTagHelperResolver _tagHelperResolver;
     private readonly RemoteTagHelperDeltaProvider _tagHelperDeltaProvider;
 
-    internal RemoteTagHelperProviderService(IServiceBroker serviceBroker, ITelemetryReporter telemetryReporter)
+    internal RemoteTagHelperProviderService(IServiceBroker serviceBroker, ITelemetryReporter telemetryReporter, ExportProvider exportProvider)
         : base(serviceBroker)
     {
         _tagHelperResolver = new RemoteTagHelperResolver(telemetryReporter);
-        _tagHelperDeltaProvider = new RemoteTagHelperDeltaProvider();
+        _tagHelperDeltaProvider = exportProvider.GetExportedValue<RemoteTagHelperDeltaProvider>().AssumeNotNull();
     }
 
     public ValueTask<FetchTagHelpersResult> FetchTagHelpersAsync(
diff --git a/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RemoteTagHelperProviderServiceFactory.cs b/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RemoteTagHelperProviderServiceFactory.cs
index b21d65330d4..7e82744047c 100644
--- a/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RemoteTagHelperProviderServiceFactory.cs
+++ b/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RemoteTagHelperProviderServiceFactory.cs
@@ -3,6 +3,7 @@
 
 using Microsoft.AspNetCore.Razor.Telemetry;
 using Microsoft.ServiceHub.Framework;
+using Microsoft.VisualStudio.Composition;
 
 namespace Microsoft.CodeAnalysis.Remote.Razor;
 
@@ -14,6 +15,6 @@ public RemoteTagHelperProviderServiceFactory()
     {
     }
 
-    protected override IRemoteTagHelperProviderService CreateService(IServiceBroker serviceBroker, ITelemetryReporter telemetryReporter)
-        => new RemoteTagHelperProviderService(serviceBroker, telemetryReporter);
+    protected override IRemoteTagHelperProviderService CreateService(IServiceBroker serviceBroker, ITelemetryReporter telemetryReporter, ExportProvider exportProvider)
+        => new RemoteTagHelperProviderService(serviceBroker, telemetryReporter, exportProvider);
 }

From df3b5eae383433d008d80075967e83822528156d Mon Sep 17 00:00:00 2001
From: David Wengier <david.wengier@microsoft.com>
Date: Tue, 20 Feb 2024 11:05:37 +1100
Subject: [PATCH 2/6] Add launch profile for debugging the OOP service

---
 .gitignore                                    |  1 -
 .../SampleApp/Properties/launchSettings.json  | 12 ++++++++++
 .../.gitignore                                |  1 -
 .../Properties/launchSettings.json            | 23 +++++++++++++++++++
 4 files changed, 35 insertions(+), 2 deletions(-)
 create mode 100644 src/Compiler/perf/Microsoft.AspNetCore.Razor.Microbenchmarks.Generator/SampleApp/Properties/launchSettings.json
 delete mode 100644 src/Razor/src/Microsoft.VisualStudio.RazorExtension/.gitignore
 create mode 100644 src/Razor/src/Microsoft.VisualStudio.RazorExtension/Properties/launchSettings.json

diff --git a/.gitignore b/.gitignore
index f82cc9bd59b..c6883ed69eb 100644
--- a/.gitignore
+++ b/.gitignore
@@ -12,7 +12,6 @@
 *.user
 *.userosscache
 *.sln.docstates
-launchSettings.json
 
 # Build results
 artifacts/
diff --git a/src/Compiler/perf/Microsoft.AspNetCore.Razor.Microbenchmarks.Generator/SampleApp/Properties/launchSettings.json b/src/Compiler/perf/Microsoft.AspNetCore.Razor.Microbenchmarks.Generator/SampleApp/Properties/launchSettings.json
new file mode 100644
index 00000000000..b26bcffee09
--- /dev/null
+++ b/src/Compiler/perf/Microsoft.AspNetCore.Razor.Microbenchmarks.Generator/SampleApp/Properties/launchSettings.json
@@ -0,0 +1,12 @@
+{
+  "profiles": {
+    "SampleApp": {
+      "commandName": "Project",
+      "launchBrowser": true,
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      },
+      "applicationUrl": "https://localhost:53331;http://localhost:53332"
+    }
+  }
+}
\ No newline at end of file
diff --git a/src/Razor/src/Microsoft.VisualStudio.RazorExtension/.gitignore b/src/Razor/src/Microsoft.VisualStudio.RazorExtension/.gitignore
deleted file mode 100644
index 5f282702bb0..00000000000
--- a/src/Razor/src/Microsoft.VisualStudio.RazorExtension/.gitignore
+++ /dev/null
@@ -1 +0,0 @@
-
\ No newline at end of file
diff --git a/src/Razor/src/Microsoft.VisualStudio.RazorExtension/Properties/launchSettings.json b/src/Razor/src/Microsoft.VisualStudio.RazorExtension/Properties/launchSettings.json
new file mode 100644
index 00000000000..63a3c7f6e0c
--- /dev/null
+++ b/src/Razor/src/Microsoft.VisualStudio.RazorExtension/Properties/launchSettings.json
@@ -0,0 +1,23 @@
+{
+  "profiles": {
+    "Razor": {
+      "commandName": "Project",
+      "environmentVariables": {
+        "CPS_DiagnosticRuntime": "1",
+        "CPS_MetricsCollection": "1",
+        "ServiceHubTraceLevel": "All",
+      },
+      "nativeDebugging": true
+    },
+    "Razor (with ServiceHub debugging)": {
+      "commandName": "Project",
+      "environmentVariables": {
+        "CPS_DiagnosticRuntime": "1",
+        "CPS_MetricsCollection": "1",
+        "ServiceHubTraceLevel": "All",
+        "SERVICEHUBDEBUGHOSTONSTARTUP": "ServiceHub.RoslynCodeAnalysisService.exe"
+      },
+      "nativeDebugging": true
+    }
+  }
+}
\ No newline at end of file

From ca941660ab5bccaa76c86703de1b1c3a056a052f Mon Sep 17 00:00:00 2001
From: David Wengier <david.wengier@microsoft.com>
Date: Tue, 20 Feb 2024 15:14:53 +1100
Subject: [PATCH 3/6] Remove telemetry reporter that will always be null

---
 .../RazorServiceFactoryBase.cs                         | 10 ++--------
 .../RemoteTagHelperProviderService.cs                  |  5 ++---
 .../RemoteTagHelperProviderServiceFactory.cs           |  5 ++---
 .../RemoteTagHelperResolver.cs                         |  7 ++++---
 4 files changed, 10 insertions(+), 17 deletions(-)

diff --git a/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RazorServiceFactoryBase.cs b/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RazorServiceFactoryBase.cs
index 08d6b88c01e..cd24c0ac426 100644
--- a/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RazorServiceFactoryBase.cs
+++ b/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RazorServiceFactoryBase.cs
@@ -23,7 +23,6 @@ namespace Microsoft.CodeAnalysis.Remote.Razor;
 internal abstract partial class RazorServiceFactoryBase<TService> : IServiceHubServiceFactory where TService : class
 {
     private readonly RazorServiceDescriptorsWrapper _razorServiceDescriptors;
-    private ITelemetryReporter? _telemetryReporter;
 
     /// <summary>
     /// </summary>
@@ -46,8 +45,6 @@ public Task<object> CreateAsync(
         // Dispose the AuthorizationServiceClient since we won't be using it
         authorizationServiceClient?.Dispose();
 
-        _telemetryReporter = (ITelemetryReporter)hostProvidedServices.GetService(typeof(ITelemetryReporter));
-
         return Task.FromResult((object)Create(stream.UsePipe(), serviceBroker));
     }
 
@@ -56,10 +53,7 @@ internal TService Create(IDuplexPipe pipe, IServiceBroker serviceBroker)
         var descriptor = _razorServiceDescriptors.GetDescriptorForServiceFactory(typeof(TService));
         var serverConnection = descriptor.ConstructRpcConnection(pipe);
 
-        var service = CreateService(serviceBroker,
-            // TODO: This seems to always be null. Suspect this was intended to be something different.
-            _telemetryReporter ?? NoOpTelemetryReporter.Instance,
-            _exportProvider);
+        var service = CreateService(serviceBroker, _exportProvider);
 
         serverConnection.AddLocalRpcTarget(service);
         serverConnection.StartListening();
@@ -67,5 +61,5 @@ internal TService Create(IDuplexPipe pipe, IServiceBroker serviceBroker)
         return service;
     }
 
-    protected abstract TService CreateService(IServiceBroker serviceBroker, ITelemetryReporter telemetryReporter, ExportProvider exportProvider);
+    protected abstract TService CreateService(IServiceBroker serviceBroker, ExportProvider exportProvider);
 }
diff --git a/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RemoteTagHelperProviderService.cs b/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RemoteTagHelperProviderService.cs
index 0fa723e3e4b..02f906861ec 100644
--- a/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RemoteTagHelperProviderService.cs
+++ b/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RemoteTagHelperProviderService.cs
@@ -8,7 +8,6 @@
 using Microsoft.AspNetCore.Razor.Language;
 using Microsoft.AspNetCore.Razor.PooledObjects;
 using Microsoft.AspNetCore.Razor.Serialization;
-using Microsoft.AspNetCore.Razor.Telemetry;
 using Microsoft.AspNetCore.Razor.Utilities;
 using Microsoft.CodeAnalysis.ExternalAccess.Razor;
 using Microsoft.CodeAnalysis.ExternalAccess.Razor.Api;
@@ -22,10 +21,10 @@ internal sealed class RemoteTagHelperProviderService : RazorServiceBase, IRemote
     private readonly RemoteTagHelperResolver _tagHelperResolver;
     private readonly RemoteTagHelperDeltaProvider _tagHelperDeltaProvider;
 
-    internal RemoteTagHelperProviderService(IServiceBroker serviceBroker, ITelemetryReporter telemetryReporter, ExportProvider exportProvider)
+    internal RemoteTagHelperProviderService(IServiceBroker serviceBroker, ExportProvider exportProvider)
         : base(serviceBroker)
     {
-        _tagHelperResolver = new RemoteTagHelperResolver(telemetryReporter);
+        _tagHelperResolver = exportProvider.GetExportedValue<RemoteTagHelperResolver>().AssumeNotNull();
         _tagHelperDeltaProvider = exportProvider.GetExportedValue<RemoteTagHelperDeltaProvider>().AssumeNotNull();
     }
 
diff --git a/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RemoteTagHelperProviderServiceFactory.cs b/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RemoteTagHelperProviderServiceFactory.cs
index 7e82744047c..47f2566f076 100644
--- a/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RemoteTagHelperProviderServiceFactory.cs
+++ b/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RemoteTagHelperProviderServiceFactory.cs
@@ -1,7 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-using Microsoft.AspNetCore.Razor.Telemetry;
 using Microsoft.ServiceHub.Framework;
 using Microsoft.VisualStudio.Composition;
 
@@ -15,6 +14,6 @@ public RemoteTagHelperProviderServiceFactory()
     {
     }
 
-    protected override IRemoteTagHelperProviderService CreateService(IServiceBroker serviceBroker, ITelemetryReporter telemetryReporter, ExportProvider exportProvider)
-        => new RemoteTagHelperProviderService(serviceBroker, telemetryReporter, exportProvider);
+    protected override IRemoteTagHelperProviderService CreateService(IServiceBroker serviceBroker, ExportProvider exportProvider)
+        => new RemoteTagHelperProviderService(serviceBroker, exportProvider);
 }
diff --git a/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RemoteTagHelperResolver.cs b/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RemoteTagHelperResolver.cs
index 1151149a062..b483b8c2039 100644
--- a/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RemoteTagHelperResolver.cs
+++ b/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RemoteTagHelperResolver.cs
@@ -4,23 +4,24 @@
 using System;
 using System.Collections.Generic;
 using System.Collections.Immutable;
+using System.Composition;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Razor;
 using Microsoft.AspNetCore.Razor.Language;
 using Microsoft.AspNetCore.Razor.ProjectEngineHost;
-using Microsoft.AspNetCore.Razor.Telemetry;
 
 namespace Microsoft.CodeAnalysis.Remote.Razor;
 
-internal class RemoteTagHelperResolver(ITelemetryReporter telemetryReporter)
+[Export(typeof(RemoteTagHelperResolver)), Shared]
+internal class RemoteTagHelperResolver()
 {
     /// <summary>
     /// A map of configuration names to <see cref="IProjectEngineFactory"/> instances.
     /// </summary>
     private static readonly Dictionary<string, IProjectEngineFactory> s_configurationNameToFactoryMap = CreateConfigurationNameToFactoryMap();
 
-    private readonly CompilationTagHelperResolver _compilationTagHelperResolver = new(telemetryReporter);
+    private readonly CompilationTagHelperResolver _compilationTagHelperResolver = new(telemetryReporter: null);
 
     private static Dictionary<string, IProjectEngineFactory> CreateConfigurationNameToFactoryMap()
     {

From 7bde481f6d7bd2e6430bbb2bf84cbcfe6a7099a5 Mon Sep 17 00:00:00 2001
From: David Wengier <david.wengier@microsoft.com>
Date: Tue, 20 Feb 2024 15:15:53 +1100
Subject: [PATCH 4/6] Initialize asyncronously

---
 .../RazorServiceFactoryBase.ExportProvider.cs         | 11 +++++++----
 .../RazorServiceFactoryBase.cs                        |  9 +++++----
 2 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RazorServiceFactoryBase.ExportProvider.cs b/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RazorServiceFactoryBase.ExportProvider.cs
index a89afc88009..0a6779443c2 100644
--- a/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RazorServiceFactoryBase.ExportProvider.cs
+++ b/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RazorServiceFactoryBase.ExportProvider.cs
@@ -5,6 +5,7 @@
 using System.Reflection;
 using System.Threading.Tasks;
 using Microsoft.VisualStudio.Composition;
+using Microsoft.VisualStudio.Threading;
 
 namespace Microsoft.CodeAnalysis.Remote.Razor;
 
@@ -12,17 +13,19 @@ internal abstract partial class RazorServiceFactoryBase<TService>
 {
     internal static readonly ImmutableArray<Assembly> RemoteHostAssemblies = [typeof(RazorServiceFactoryBase<TService>).Assembly];
 
-    private static readonly ExportProvider _exportProvider = CreateExportProvider();
+#pragma warning disable VSTHRD012 // Provide JoinableTaskFactory where allowed
+    private static readonly AsyncLazy<ExportProvider> s_exportProviderLazy = new(GetExportProviderAsync);
+#pragma warning restore VSTHRD012 // Provide JoinableTaskFactory where allowed
 
     // Inspired by https://github.com/dotnet/roslyn/blob/25aa74d725e801b8232dbb3e5abcda0fa72da8c5/src/Workspaces/Remote/ServiceHub/Host/RemoteWorkspaceManager.cs#L77
-    private static ExportProvider CreateExportProvider()
+    private static async Task<ExportProvider> GetExportProviderAsync()
     {
         var resolver = Resolver.DefaultInstance;
         var discovery = new AttributedPartDiscovery(resolver, isNonPublicSupported: true); // MEFv2 only
-        var parts = Task.Run(async () => await discovery.CreatePartsAsync(RemoteHostAssemblies).ConfigureAwait(false)).GetAwaiter().GetResult();
+        var parts = await discovery.CreatePartsAsync(RemoteHostAssemblies).ConfigureAwait(false);
         var catalog = ComposableCatalog.Create(resolver).AddParts(parts);
 
-        var configuration = CompositionConfiguration.Create(catalog);
+        var configuration = CompositionConfiguration.Create(catalog).ThrowOnErrors();
         var runtimeComposition = RuntimeComposition.CreateRuntimeComposition(configuration);
         var exportProviderFactory = runtimeComposition.CreateExportProviderFactory();
         return exportProviderFactory.CreateExportProvider();
diff --git a/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RazorServiceFactoryBase.cs b/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RazorServiceFactoryBase.cs
index cd24c0ac426..1f7bb6ba6c3 100644
--- a/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RazorServiceFactoryBase.cs
+++ b/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RazorServiceFactoryBase.cs
@@ -5,7 +5,6 @@
 using System.IO;
 using System.IO.Pipelines;
 using System.Threading.Tasks;
-using Microsoft.AspNetCore.Razor.Telemetry;
 using Microsoft.CodeAnalysis.ExternalAccess.Razor;
 using Microsoft.ServiceHub.Framework;
 using Microsoft.ServiceHub.Framework.Services;
@@ -45,15 +44,17 @@ public Task<object> CreateAsync(
         // Dispose the AuthorizationServiceClient since we won't be using it
         authorizationServiceClient?.Dispose();
 
-        return Task.FromResult((object)Create(stream.UsePipe(), serviceBroker));
+        return CreateAsync(stream.UsePipe(), serviceBroker);
     }
 
-    internal TService Create(IDuplexPipe pipe, IServiceBroker serviceBroker)
+    private async Task<object> CreateAsync(IDuplexPipe pipe, IServiceBroker serviceBroker)
     {
         var descriptor = _razorServiceDescriptors.GetDescriptorForServiceFactory(typeof(TService));
         var serverConnection = descriptor.ConstructRpcConnection(pipe);
 
-        var service = CreateService(serviceBroker, _exportProvider);
+        var exportProvider = await s_exportProviderLazy.GetValueAsync().ConfigureAwait(false);
+
+        var service = CreateService(serviceBroker, exportProvider);
 
         serverConnection.AddLocalRpcTarget(service);
         serverConnection.StartListening();

From 1ae2180bac7ad140f04b2e312797006c6b56aaef Mon Sep 17 00:00:00 2001
From: David Wengier <david.wengier@microsoft.com>
Date: Tue, 20 Feb 2024 15:23:36 +1100
Subject: [PATCH 5/6] Bring back telemetry properly, via DI

---
 .../Microsoft.CodeAnalysis.Remote.Razor.csproj  |  4 ++++
 .../RemoteTagHelperResolver.cs                  |  6 ++++--
 .../Telemetry/OutOfProcessTelemetryReporter.cs  | 17 +++++++++++++++++
 3 files changed, 25 insertions(+), 2 deletions(-)
 create mode 100644 src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/Telemetry/OutOfProcessTelemetryReporter.cs

diff --git a/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/Microsoft.CodeAnalysis.Remote.Razor.csproj b/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/Microsoft.CodeAnalysis.Remote.Razor.csproj
index bde79e4e5e4..8d41644ee2a 100644
--- a/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/Microsoft.CodeAnalysis.Remote.Razor.csproj
+++ b/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/Microsoft.CodeAnalysis.Remote.Razor.csproj
@@ -23,6 +23,10 @@
     <ProjectReference Include="..\Microsoft.CodeAnalysis.Razor.Workspaces\Microsoft.CodeAnalysis.Razor.Workspaces.csproj" />
   </ItemGroup>
 
+  <ItemGroup>
+    <Compile Include="..\Microsoft.VisualStudio.Editor.Razor\Telemetry\TelemetryReporter.cs" Link="Telemetry\TelemetryReporter.cs" />
+  </ItemGroup>
+
   <ItemGroup>
     <!--
       Pinning packages to avoid misaligned reference CI failures.
diff --git a/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RemoteTagHelperResolver.cs b/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RemoteTagHelperResolver.cs
index b483b8c2039..ea7ebe373a9 100644
--- a/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RemoteTagHelperResolver.cs
+++ b/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RemoteTagHelperResolver.cs
@@ -10,18 +10,20 @@
 using Microsoft.AspNetCore.Razor;
 using Microsoft.AspNetCore.Razor.Language;
 using Microsoft.AspNetCore.Razor.ProjectEngineHost;
+using Microsoft.AspNetCore.Razor.Telemetry;
 
 namespace Microsoft.CodeAnalysis.Remote.Razor;
 
 [Export(typeof(RemoteTagHelperResolver)), Shared]
-internal class RemoteTagHelperResolver()
+[method: ImportingConstructor]
+internal class RemoteTagHelperResolver(ITelemetryReporter telemetryReporter)
 {
     /// <summary>
     /// A map of configuration names to <see cref="IProjectEngineFactory"/> instances.
     /// </summary>
     private static readonly Dictionary<string, IProjectEngineFactory> s_configurationNameToFactoryMap = CreateConfigurationNameToFactoryMap();
 
-    private readonly CompilationTagHelperResolver _compilationTagHelperResolver = new(telemetryReporter: null);
+    private readonly CompilationTagHelperResolver _compilationTagHelperResolver = new(telemetryReporter);
 
     private static Dictionary<string, IProjectEngineFactory> CreateConfigurationNameToFactoryMap()
     {
diff --git a/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/Telemetry/OutOfProcessTelemetryReporter.cs b/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/Telemetry/OutOfProcessTelemetryReporter.cs
new file mode 100644
index 00000000000..a6cd1c58303
--- /dev/null
+++ b/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/Telemetry/OutOfProcessTelemetryReporter.cs
@@ -0,0 +1,17 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the MIT license. See License.txt in the project root for license information.
+
+using System.Composition;
+using Microsoft.AspNetCore.Razor.Telemetry;
+using Microsoft.VisualStudio.Telemetry;
+
+namespace Microsoft.CodeAnalysis.Remote.Razor.Telemetry;
+
+[Export(typeof(ITelemetryReporter)), Shared]
+internal class OutOfProcessTelemetryReporter : TelemetryReporter
+{
+    public OutOfProcessTelemetryReporter()
+        : base([TelemetryService.DefaultSession])
+    {
+    }
+}

From c4fd0aa1ce97054d506adffaac598f147ce59c5f Mon Sep 17 00:00:00 2001
From: David Wengier <david.wengier@microsoft.com>
Date: Wed, 21 Feb 2024 11:15:03 +1100
Subject: [PATCH 6/6] Move MEF error detection to a test, and add some known
 current exceptions

---
 .../AbstractRazorEditorTest.cs                | 26 --------
 .../MEFComponentTests.cs                      | 60 +++++++++++++++++++
 2 files changed, 60 insertions(+), 26 deletions(-)
 create mode 100644 src/Razor/test/Microsoft.VisualStudio.Razor.IntegrationTests/MEFComponentTests.cs

diff --git a/src/Razor/test/Microsoft.VisualStudio.Razor.IntegrationTests/AbstractRazorEditorTest.cs b/src/Razor/test/Microsoft.VisualStudio.Razor.IntegrationTests/AbstractRazorEditorTest.cs
index c20bcc1e1bc..c14ee5058b4 100644
--- a/src/Razor/test/Microsoft.VisualStudio.Razor.IntegrationTests/AbstractRazorEditorTest.cs
+++ b/src/Razor/test/Microsoft.VisualStudio.Razor.IntegrationTests/AbstractRazorEditorTest.cs
@@ -63,7 +63,6 @@ public override async Task InitializeAsync()
         EnsureLSPEditorEnabled();
         await EnsureTextViewRolesAsync(ControlledHangMitigatingCancellationToken);
         await EnsureExtensionInstalledAsync(ControlledHangMitigatingCancellationToken);
-        EnsureMEFCompositionSuccessForRazor();
 
         await TestServices.Editor.PlaceCaretAsync("</PageTitle>", charsOffset: 1, ControlledHangMitigatingCancellationToken);
 
@@ -152,31 +151,6 @@ private static void EnsureLSPEditorEnabled()
         Assert.AreEqual(false, useLegacyEditor, "Expected the Legacy Razor Editor to be disabled, but it was enabled");
     }
 
-    private static void EnsureMEFCompositionSuccessForRazor()
-    {
-        var hiveDirectory = VisualStudioLogging.GetHiveDirectory();
-        var cmcPath = Path.Combine(hiveDirectory, "ComponentModelCache");
-        if (!Directory.Exists(cmcPath))
-        {
-            throw new InvalidOperationException("ComponentModelCache directory doesn't exist");
-        }
-
-        var mefErrorFile = Path.Combine(cmcPath, "Microsoft.VisualStudio.Default.err");
-        if (!File.Exists(mefErrorFile))
-        {
-            throw new InvalidOperationException("Expected ComponentModelCache error file to exist");
-        }
-
-        var txt = File.ReadAllText(mefErrorFile);
-        const string Separator = "----------- Used assemblies -----------";
-        var content = txt.Split(new string[] { Separator }, StringSplitOptions.RemoveEmptyEntries);
-        var errors = content[0];
-        if (errors.Contains("Razor"))
-        {
-            throw new InvalidOperationException($"Razor errors detected in MEF cache: {errors}");
-        }
-    }
-
     private async Task EnsureTextViewRolesAsync(CancellationToken cancellationToken)
     {
         var textView = await TestServices.Editor.GetActiveTextViewAsync(cancellationToken);
diff --git a/src/Razor/test/Microsoft.VisualStudio.Razor.IntegrationTests/MEFComponentTests.cs b/src/Razor/test/Microsoft.VisualStudio.Razor.IntegrationTests/MEFComponentTests.cs
new file mode 100644
index 00000000000..ac85a8cfe89
--- /dev/null
+++ b/src/Razor/test/Microsoft.VisualStudio.Razor.IntegrationTests/MEFComponentTests.cs
@@ -0,0 +1,60 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the MIT license. See License.txt in the project root for license information.
+
+using System.IO;
+using System.Text;
+using Xunit;
+using Xunit.Abstractions;
+
+namespace Microsoft.VisualStudio.Razor.IntegrationTests;
+
+public class MEFComponentTests(ITestOutputHelper testOutputHelper) : AbstractRazorEditorTest(testOutputHelper)
+{
+    [IdeFact]
+    public static void EnsureCompositionCreation()
+    {
+        var hiveDirectory = VisualStudioLogging.GetHiveDirectory();
+        var cmcPath = Path.Combine(hiveDirectory, "ComponentModelCache");
+
+        Assert.True(Directory.Exists(cmcPath), "ComponentModelCache directory doesn't exist");
+
+        var mefErrorFile = Path.Combine(cmcPath, "Microsoft.VisualStudio.Default.err");
+
+        Assert.True(File.Exists(mefErrorFile), "Expected ComponentModelCache error file to exist");
+
+        var section = new StringBuilder();
+        foreach (var line in File.ReadLines(mefErrorFile))
+        {
+            // Individual errors are separated by a blank lines, or with an "Error #" header
+            if (line.StartsWith("Error #") ||
+                string.IsNullOrWhiteSpace(line))
+            {
+                var error = section.ToString();
+                section.Clear();
+
+                if (error.Contains("Razor"))
+                {
+                    Assert.True(IsAllowedFailure(error), "Unexpected MEF failure: " + line);
+                }
+            }
+            else if (line.Equals("----------- Used assemblies -----------"))
+            {
+                // Finished processing errors
+                break;
+            }
+            else
+            {
+                section.AppendLine(line);
+            }
+        }
+    }
+
+    private static bool IsAllowedFailure(string error)
+    {
+        return
+            // We have a little issue with LiveShare at the moment. Doesn't seem to affect user scenarios
+            error.Contains("Microsoft.VisualStudio.LiveShare.Razor.LiveShareProjectCapabilityResolver") ||
+            error.Contains("Microsoft.VisualStudio.LiveShare.Razor.Guest.GuestProjectPathProvider") ||
+            error.Contains("Microsoft.VisualStudio.LiveShare.Razor.Guest.LiveShareSessionAccessor");
+    }
+}