Merge remote-tracking branch 'upstream/main' into merge_main

NuGet.config

@@ -22,7 +22,6 @@
     <add key="richnav" value="https://pkgs.dev.azure.com/azure-public/vside/_packaging/vs-buildservices/nuget/v3/index.json" />
     <!-- Used for BenchmarkDotNet prerelease packages -->
     <add key="benchmark-dotnet-prerelease" value="https://pkgs.dev.azure.com/dnceng/public/_packaging/benchmark-dotnet-prerelease/nuget/v3/index.json" />
-    <add key="general-testing" value="https://dnceng.pkgs.visualstudio.com/public/_packaging/general-testing/nuget/v3/index.json" />
   </packageSources>
   <!--
     ****************************** AUTOGENERATED ***********************************

eng/Version.Details.xml

@@ -32,9 +32,9 @@
       <Uri>https://dev.azure.com/dnceng/internal/_git/dotnet-runtime</Uri>
       <Sha>3a25a7f1cc446b60678ed25c9d829420d6321eba</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.DotNet.Arcade.Sdk" Version="8.0.0-beta.22473.1">
+    <Dependency Name="Microsoft.DotNet.Arcade.Sdk" Version="8.0.0-beta.22480.2">
       <Uri>https://github.com/dotnet/arcade</Uri>
-      <Sha>ba4d2568dd2e3e7538feeaba60215f7bcb99e89c</Sha>
+      <Sha>60e9ab3c31d68167f8dac5b8e2c536deb12ef737</Sha>
     </Dependency>
   </ToolsetDependencies>
 </Dependencies>

eng/Versions.props

@@ -81,7 +81,7 @@
     <RoslynPackageVersion>4.4.0-2.22424.2</RoslynPackageVersion>
     <VisualStudioLanguageServerProtocolVersion>17.4.1008-preview</VisualStudioLanguageServerProtocolVersion>
     <MicrosoftNetCompilersToolsetVersion>4.4.0-1.final</MicrosoftNetCompilersToolsetVersion>
-    <MicrosoftCommonLanguageServerProtocolFrameworkPackageVersion>4.4.0-3.22463.10</MicrosoftCommonLanguageServerProtocolFrameworkPackageVersion>
+    <MicrosoftCommonLanguageServerProtocolFrameworkPackageVersion>4.5.0-1.22480.13</MicrosoftCommonLanguageServerProtocolFrameworkPackageVersion>
   </PropertyGroup>
   <PropertyGroup Label="Manual">
     <!-- dotnet/runtime packages -->
@@ -131,7 +131,6 @@
     <NewtonsoftJsonPackageVersion>13.0.1</NewtonsoftJsonPackageVersion>
     <NerdbankStreamsPackageVersion>2.8.57</NerdbankStreamsPackageVersion>
     <NuGetSolutionRestoreManagerInteropVersion>4.8.0</NuGetSolutionRestoreManagerInteropVersion>
-
     <OmniSharpExtensionsLanguageServerPackageVersion>0.19.5</OmniSharpExtensionsLanguageServerPackageVersion>
     <OmniSharpExtensionsLanguageProtocolPackageVersion>$(OmniSharpExtensionsLanguageServerPackageVersion)</OmniSharpExtensionsLanguageProtocolPackageVersion>
     <OmniSharpMSBuildPackageVersion>1.39.1</OmniSharpMSBuildPackageVersion>

eng/common/init-tools-native.ps1

@@ -113,6 +113,7 @@ try {
             $ToolPath = Convert-Path -Path $BinPath
             Write-Host "Adding $ToolName to the path ($ToolPath)..."
             Write-Host "##vso[task.prependpath]$ToolPath"
+            $env:PATH = "$ToolPath;$env:PATH"
             $InstalledTools += @{ $ToolName = $ToolDirectory.FullName }
           }
         }

eng/common/templates/job/execute-sdl.yml

@@ -34,7 +34,7 @@ jobs:
 - job: Run_SDL
   dependsOn: ${{ parameters.dependsOn }}
   displayName: Run SDL tool
-  condition: eq( ${{ parameters.enable }}, 'true')
+  condition: and(succeededOrFailed(), eq( ${{ parameters.enable }}, 'true'))
   variables:
     - group: DotNet-VSTS-Bot
     - name: AzDOProjectName

eng/common/templates/job/job.yml

@@ -25,6 +25,7 @@ parameters:
   enablePublishTestResults: false
   enablePublishUsingPipelines: false
   disableComponentGovernance: false
+  componentGovernanceIgnoreDirectories: ''
   mergeTestResults: false
   testRunTitle: ''
   testResultsFormat: ''
@@ -146,6 +147,8 @@ jobs:
   - ${{ if and(eq(parameters.runAsPublic, 'false'), ne(variables['System.TeamProject'], 'public'), notin(variables['Build.Reason'], 'PullRequest'), ne(parameters.disableComponentGovernance, 'true')) }}:
       - task: ComponentGovernanceComponentDetection@0
         continueOnError: true
+        inputs:
+          ignoreDirectories: ${{ parameters.componentGovernanceIgnoreDirectories }}
 
   - ${{ if eq(parameters.enableMicrobuild, 'true') }}:
     - ${{ if and(eq(parameters.runAsPublic, 'false'), ne(variables['System.TeamProject'], 'public'), notin(variables['Build.Reason'], 'PullRequest')) }}:
@@ -223,4 +226,5 @@ jobs:
       parameters:
         PackageVersion: ${{ parameters.packageVersion}}
         BuildDropPath: ${{ parameters.buildDropPath }}
+        IgnoreDirectories: ${{ parameters.componentGovernanceIgnoreDirectories }}
 

eng/common/templates/jobs/source-build.yml

@@ -14,7 +14,7 @@ parameters:
   # This is the default platform provided by Arcade, intended for use by a managed-only repo.
   defaultManagedPlatform:
     name: 'Managed'
-    container: 'mcr.microsoft.com/dotnet-buildtools/prereqs:centos-stream8-20220809204800-17a4aab'
+    container: 'mcr.microsoft.com/dotnet-buildtools/prereqs:centos-stream8-latest'
 
   # Defines the platforms on which to run build jobs. One job is created for each platform, and the
   # object in this array is sent to the job template as 'platform'. If no platforms are specified,

eng/common/templates/post-build/post-build.yml

@@ -98,7 +98,7 @@ stages:
     jobs:
     - job:
       displayName: NuGet Validation
-      condition: eq( ${{ parameters.enableNugetValidation }}, 'true')
+      condition: and(succeededOrFailed(), eq( ${{ parameters.enableNugetValidation }}, 'true'))
       pool:
         # We don't use the collection uri here because it might vary (.visualstudio.com vs. dev.azure.com)
         ${{ if eq(variables['System.TeamProject'], 'DevDiv') }}:
@@ -282,4 +282,4 @@ stages:
               -MaestroToken '$(MaestroApiAccessToken)'
               -WaitPublishingFinish true
               -ArtifactsPublishingAdditionalParameters '${{ parameters.artifactsPublishingAdditionalParameters }}'
-              -SymbolPublishingAdditionalParameters '${{ parameters.symbolPublishingAdditionalParameters }}'
+              -SymbolPublishingAdditionalParameters '${{ parameters.symbolPublishingAdditionalParameters }}'

eng/common/templates/steps/generate-sbom.yml

@@ -2,12 +2,14 @@
 # PackageName - The name of the package this SBOM represents.
 # PackageVersion - The version of the package this SBOM represents. 
 # ManifestDirPath - The path of the directory where the generated manifest files will be placed
+# IgnoreDirectories - Directories to ignore for SBOM generation. This will be passed through to the CG component detector.
 
 parameters:
   PackageVersion: 7.0.0
   BuildDropPath: '$(Build.SourcesDirectory)/artifacts'
   PackageName: '.NET'
   ManifestDirPath: $(Build.ArtifactStagingDirectory)/sbom
+  IgnoreDirectories: ''
   sbomContinueOnError: true
 
 steps:
@@ -34,6 +36,8 @@ steps:
       BuildDropPath: ${{ parameters.buildDropPath }}
       PackageVersion: ${{ parameters.packageVersion }}
       ManifestDirPath: ${{ parameters.manifestDirPath }}
+      ${{ if ne(parameters.IgnoreDirectories, '') }}:
+        AdditionalComponentDetectorArgs: '--IgnoreDirectories ${{ parameters.IgnoreDirectories }}'
 
 - task: PublishPipelineArtifact@1
   displayName: Publish SBOM manifest

global.json

@@ -19,7 +19,7 @@
     "version": "7.0.100-rc.1.22431.12"
   },
   "msbuild-sdks": {
-    "Microsoft.DotNet.Arcade.Sdk": "8.0.0-beta.22473.1",
+    "Microsoft.DotNet.Arcade.Sdk": "8.0.0-beta.22480.2",
     "Yarn.MSBuild": "1.22.10"
   }
 }

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer.Common/RazorLanguageServerCustomMessageTargets.cs

@@ -42,5 +42,7 @@ namespace Microsoft.AspNetCore.Razor.LanguageServer.Common
         public const string RazorImplementationEndpointName = "razor/implementation";
 
         public const string RazorOnAutoInsertEndpointName = "razor/onAutoInsert";
+
+        public const string RazorValidateBreakpointRangeName = "razor/validateBreakpointRange";
     }
 }

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer.Protocol/DelegatedTypes.cs

@@ -14,6 +14,11 @@ internal record DelegatedPositionParams(
     Position ProjectedPosition,
     RazorLanguageKind ProjectedKind) : IDelegatedParams;
 
+internal record DelegatedValidateBreakpointRangeParams(
+    VersionedTextDocumentIdentifier HostDocument,
+    Range ProjectedRange,
+    RazorLanguageKind ProjectedKind) : IDelegatedParams;
+
 internal record DelegatedOnAutoInsertParams(
     VersionedTextDocumentIdentifier HostDocument,
     Position ProjectedPosition,

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/AbstractRazorDelegatingEndpoint.cs

@@ -34,10 +34,7 @@ namespace Microsoft.AspNetCore.Razor.LanguageServer
             Logger = logger ?? throw new ArgumentNullException(nameof(logger));
         }
 
-        /// <summary>
-        /// The delegated object to send to the <see cref="CustomMessageTarget"/>
-        /// </summary>
-        protected abstract IDelegatedParams? CreateDelegatedParams(TRequest request, RazorRequestContext razorRequestContext, Projection projection, CancellationToken cancellationToken);
+        protected virtual bool OnlySingleServer { get; } = true;
 
         /// <summary>
         /// The name of the endpoint to delegate to, from <see cref="RazorLanguageServerCustomMessageTargets"/>. This is the
@@ -51,6 +48,11 @@ namespace Microsoft.AspNetCore.Razor.LanguageServer
 
         public bool MutatesSolutionState { get; } = false;
 
+        /// <summary>
+        /// The delegated object to send to the <see cref="CustomMessageTarget"/>
+        /// </summary>
+        protected abstract Task<IDelegatedParams?> CreateDelegatedParamsAsync(TRequest request, RazorRequestContext requestContext, Projection projection, CancellationToken cancellationToken);
+
         /// <summary>
         /// If the response needs to be handled, such as for remapping positions back, override and handle here
         /// </summary>
@@ -75,7 +77,7 @@ namespace Microsoft.AspNetCore.Razor.LanguageServer
         /// <summary>
         /// Implementation for <see cref="HandleRequestAsync(TRequest, RazorRequestContext, CancellationToken)"/>
         /// </summary>
-        public async Task<TResponse?> HandleRequestAsync(TRequest request, RazorRequestContext context, CancellationToken cancellationToken)
+        public async Task<TResponse?> HandleRequestAsync(TRequest request, RazorRequestContext requestContext, CancellationToken cancellationToken)
         {
             if (request is null)
             {
@@ -87,25 +89,25 @@ namespace Microsoft.AspNetCore.Razor.LanguageServer
                 return default;
             }
 
-            var documentContext = context.DocumentContext;
+            var documentContext = requestContext.DocumentContext;
             if (documentContext is null)
             {
                 return default;
             }
 
-            var projection = await _documentMappingService.TryGetProjectionAsync(documentContext, request.Position, context.Logger, cancellationToken).ConfigureAwait(false);
+            var projection = await _documentMappingService.TryGetProjectionAsync(documentContext, request.Position, requestContext.Logger, cancellationToken).ConfigureAwait(false);
             if (projection is null)
             {
                 return default;
             }
 
-            var response = await TryHandleAsync(request, context, projection, cancellationToken).ConfigureAwait(false);
+            var response = await TryHandleAsync(request, requestContext, projection, cancellationToken).ConfigureAwait(false);
             if (response is not null && response is not ISumType { Value: null })
             {
                 return response;
             }
 
-            if (!_languageServerFeatureOptions.SingleServerSupport)
+            if (OnlySingleServer && !_languageServerFeatureOptions.SingleServerSupport)
             {
                 return default;
             }
@@ -117,7 +119,8 @@ namespace Microsoft.AspNetCore.Razor.LanguageServer
                 return default;
             }
 
-            var delegatedParams = CreateDelegatedParams(request, context, projection, cancellationToken);
+            var delegatedParams = await CreateDelegatedParamsAsync(request, requestContext, projection, cancellationToken);
+
             if (delegatedParams is null)
             {
                 // I guess they don't want to delegate... fine then!
@@ -130,7 +133,7 @@ namespace Microsoft.AspNetCore.Razor.LanguageServer
                 return default;
             }
 
-            var remappedResponse = await HandleDelegatedResponseAsync(delegatedRequest, request, context, projection, cancellationToken).ConfigureAwait(false);
+            var remappedResponse = await HandleDelegatedResponseAsync(delegatedRequest, request, requestContext, projection, cancellationToken).ConfigureAwait(false);
 
             return remappedResponse;
         }

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/AutoInsert/OnAutoInsertEndpoint.cs

@@ -112,28 +112,28 @@ namespace Microsoft.AspNetCore.Razor.LanguageServer.AutoInsert
             return null;
         }
 
-        protected override IDelegatedParams? CreateDelegatedParams(OnAutoInsertParamsBridge request, RazorRequestContext requestContext, Projection projection, CancellationToken cancellationToken)
+        protected override Task<IDelegatedParams?> CreateDelegatedParamsAsync(OnAutoInsertParamsBridge request, RazorRequestContext requestContext, Projection projection, CancellationToken cancellationToken)
         {
             var documentContext = requestContext.GetRequiredDocumentContext();
             if (projection.LanguageKind == RazorLanguageKind.Html &&
                !s_htmlAllowedTriggerCharacters.Contains(request.Character))
             {
                 Logger.LogInformation("Inapplicable HTML trigger char {request.Character}.", request.Character);
-                return null;
+                return Task.FromResult<IDelegatedParams?>(null);
             }
             else if (projection.LanguageKind == RazorLanguageKind.CSharp &&
                 !s_cSharpAllowedTriggerCharacters.Contains(request.Character))
             {
                 Logger.LogInformation("Inapplicable C# trigger char {request.Character}.", request.Character);
-                return null;
+                return Task.FromResult<IDelegatedParams?>(null);
             }
 
-            return new DelegatedOnAutoInsertParams(
+            return Task.FromResult<IDelegatedParams?>(new DelegatedOnAutoInsertParams(
                 documentContext.Identifier,
                 projection.Position,
                 projection.LanguageKind,
                 request.Character,
-                request.Options);
+                request.Options));
         }
 
         protected override async Task<VSInternalDocumentOnAutoInsertResponseItem?> HandleDelegatedResponseAsync(

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/Completion/RazorCompletionItemResolver.cs

@@ -132,5 +132,3 @@ namespace Microsoft.AspNetCore.Razor.LanguageServer.Completion
         }
     }
 }
-
-

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/Debugging/ValidateBreakpointRangeEndpoint.cs

@@ -0,0 +1,87 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the MIT license. See License.txt in the project root for license information.
+
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Razor.LanguageServer.Common;
+using Microsoft.AspNetCore.Razor.LanguageServer.EndpointContracts;
+using Microsoft.AspNetCore.Razor.LanguageServer.Protocol;
+using Microsoft.CodeAnalysis.Razor.Workspaces;
+using Microsoft.Extensions.Logging;
+using Microsoft.VisualStudio.LanguageServer.Protocol;
+
+namespace Microsoft.AspNetCore.Razor.LanguageServer.Debugging
+{
+    internal class ValidateBreakpointRangeEndpoint : AbstractRazorDelegatingEndpoint<ValidateBreakpointRangeParamsBridge, Range?>, IValidateBreakpointRangeEndpoint
+    {
+        private readonly RazorDocumentMappingService _documentMappingService;
+
+        public ValidateBreakpointRangeEndpoint(
+            RazorDocumentMappingService documentMappingService,
+            LanguageServerFeatureOptions languageServerFeatureOptions,
+            ClientNotifierServiceBase languageServer,
+            ILoggerFactory loggerFactory)
+            : base(languageServerFeatureOptions, documentMappingService, languageServer, loggerFactory.CreateLogger<ValidateBreakpointRangeEndpoint>())
+        {
+            _documentMappingService = documentMappingService ?? throw new ArgumentNullException(nameof(documentMappingService));
+        }
+
+        protected override bool OnlySingleServer => false;
+
+        protected override string CustomMessageTarget => RazorLanguageServerCustomMessageTargets.RazorValidateBreakpointRangeName;
+
+        public RegistrationExtensionResult GetRegistration(VSInternalClientCapabilities clientCapabilities)
+        {
+            const string ServerCapability = "_vs_breakableRangeProvider";
+
+            return new RegistrationExtensionResult(ServerCapability, true);
+        }
+
+        protected override Task<Range?> TryHandleAsync(ValidateBreakpointRangeParamsBridge request, RazorRequestContext requestContext, Projection projection, CancellationToken cancellationToken)
+        {
+            // no such thing as Razor breakpoints (yet?!)
+            return Task.FromResult<Range?>(null);
+        }
+
+        protected async override Task<IDelegatedParams?> CreateDelegatedParamsAsync(ValidateBreakpointRangeParamsBridge request, RazorRequestContext requestContext, Projection projection, CancellationToken cancellationToken)
+        {
+            // only C# supports breakpoints
+            if (projection.LanguageKind != RazorLanguageKind.CSharp)
+            {
+                return null;
+            }
+
+            var documentContext = requestContext.GetRequiredDocumentContext();
+            var codeDocument = await documentContext.GetCodeDocumentAsync(cancellationToken).ConfigureAwait(false);
+
+            if (!_documentMappingService.TryMapToProjectedDocumentRange(codeDocument, request.Range, out var projectedRange))
+            {
+                return null;
+            }
+
+            return new DelegatedValidateBreakpointRangeParams(
+                documentContext.Identifier,
+                projectedRange,
+                projection.LanguageKind);
+        }
+
+        protected async override Task<Range?> HandleDelegatedResponseAsync(Range? delegatedResponse, ValidateBreakpointRangeParamsBridge originalRequest, RazorRequestContext requestContext, Projection projection, CancellationToken cancellationToken)
+        {
+            if (delegatedResponse is null)
+            {
+                return null;
+            }
+
+            var documentContext = requestContext.GetRequiredDocumentContext();
+            var codeDocument = await documentContext.GetCodeDocumentAsync(cancellationToken).ConfigureAwait(false);
+
+            if (_documentMappingService.TryMapFromProjectedDocumentRange(codeDocument, delegatedResponse, out var projectedRange))
+            {
+                return projectedRange;
+            }
+
+            return null;
+        }
+    }
+}

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/Definition/RazorDefinitionEndpoint.cs

@@ -99,13 +99,13 @@ namespace Microsoft.AspNetCore.Razor.LanguageServer.Definition
             };
         }
 
-        protected override IDelegatedParams CreateDelegatedParams(TextDocumentPositionParamsBridge request, RazorRequestContext requestContext, Projection projection, CancellationToken cancellationToken)
+        protected override Task<IDelegatedParams?> CreateDelegatedParamsAsync(TextDocumentPositionParamsBridge request, RazorRequestContext requestContext, Projection projection, CancellationToken cancellationToken)
         {
             var documentContext = requestContext.GetRequiredDocumentContext();
-            return new DelegatedPositionParams(
+            return Task.FromResult<IDelegatedParams?>(new DelegatedPositionParams(
                     documentContext.Identifier,
                     projection.Position,
-                    projection.LanguageKind);
+                    projection.LanguageKind));
         }
 
         protected async override Task<DefinitionResult?> HandleDelegatedResponseAsync(DefinitionResult? response, TextDocumentPositionParamsBridge originalRequest, RazorRequestContext requestContext, Projection projection, CancellationToken cancellationToken)

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/DocumentHighlighting/DocumentHighlightEndpoint.cs

@@ -38,26 +38,23 @@ namespace Microsoft.AspNetCore.Razor.LanguageServer.DocumentHighlighting
             return new RegistrationExtensionResult(ServerCapability, options);
         }
 
-        /// <inheritdoc/>
         protected override string CustomMessageTarget => RazorLanguageServerCustomMessageTargets.RazorDocumentHighlightEndpointName;
 
-        /// <inheritdoc/>
         protected override Task<DocumentHighlight[]?> TryHandleAsync(DocumentHighlightParamsBridge request, RazorRequestContext requestContext, Projection projection, CancellationToken cancellationToken)
         {
             // We don't handle this in any particular way for Razor, we just delegate
             return Task.FromResult<DocumentHighlight[]?>(null);
         }
 
-        /// <inheritdoc/>
-        protected override IDelegatedParams CreateDelegatedParams(DocumentHighlightParamsBridge request, RazorRequestContext requestContext, Projection projection, CancellationToken cancellationToken)
+        protected override Task<IDelegatedParams?> CreateDelegatedParamsAsync(DocumentHighlightParamsBridge request, RazorRequestContext requestContext, Projection projection, CancellationToken cancellationToken)
         {
             var documentContext = requestContext.GetRequiredDocumentContext();
-            return new DelegatedPositionParams(
+            return Task.FromResult<IDelegatedParams?>(new DelegatedPositionParams(
                     documentContext.Identifier,
                     projection.Position,
-                    projection.LanguageKind);
+                    projection.LanguageKind));
         }
-        /// <inheritdoc/>
+
         protected override async Task<DocumentHighlight[]?> HandleDelegatedResponseAsync(DocumentHighlight[]? response, DocumentHighlightParamsBridge request, RazorRequestContext requestContext, Projection projection, CancellationToken cancellationToken)
         {
             var documentContext = requestContext.GetRequiredDocumentContext();

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/DocumentSynchronization/RazorDidChangeTextDocumentEndpoint.cs

@@ -54,12 +54,12 @@ internal class RazorDidChangeTextDocumentEndpoint : IVSDidChangeTextDocumentEndp
         return request.TextDocument;
     }
 
-    public async Task HandleNotificationAsync(DidChangeTextDocumentParams request, RazorRequestContext context, CancellationToken cancellationToken)
+    public async Task HandleNotificationAsync(DidChangeTextDocumentParams request, RazorRequestContext requestContext, CancellationToken cancellationToken)
     {
-        var documentContext = context.GetRequiredDocumentContext();
+        var documentContext = requestContext.GetRequiredDocumentContext();
 
         var sourceText = await documentContext.GetSourceTextAsync(cancellationToken);
-        sourceText = ApplyContentChanges(request.ContentChanges, sourceText, context.Logger);
+        sourceText = ApplyContentChanges(request.ContentChanges, sourceText, requestContext.Logger);
 
         await _projectSnapshotManagerDispatcher.RunOnDispatcherThreadAsync(
             () => _projectService.UpdateDocument(documentContext.FilePath, sourceText, request.TextDocument.Version),

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/DocumentSynchronization/RazorDidCloseTextDocumentEndpoint.cs

@@ -41,7 +41,7 @@ internal class RazorDidCloseTextDocumentEndpoint : IVSDidCloseTextDocumentEndpoi
         return request.TextDocument;
     }
 
-    public async Task HandleNotificationAsync(DidCloseTextDocumentParams request, RazorRequestContext context, CancellationToken cancellationToken)
+    public async Task HandleNotificationAsync(DidCloseTextDocumentParams request, RazorRequestContext requestContext, CancellationToken cancellationToken)
     {
         await _projectSnapshotManagerDispatcher.RunOnDispatcherThreadAsync(
             () => _projectService.CloseDocument(request.TextDocument.Uri.GetAbsoluteOrUNCPath()),

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/DocumentSynchronization/RazorDidOpenTextDocumentEndpoint.cs

@@ -30,7 +30,7 @@ internal class RazorDidOpenTextDocumentEndpoint : IVSDidOpenTextDocumentEndpoint
         return request.TextDocument.Uri;
     }
 
-    public async Task HandleNotificationAsync(DidOpenTextDocumentParams request, RazorRequestContext context, CancellationToken cancellationToken)
+    public async Task HandleNotificationAsync(DidOpenTextDocumentParams request, RazorRequestContext requestContext, CancellationToken cancellationToken)
     {
         var sourceText = SourceText.From(request.TextDocument.Text);
 

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/DocumentSynchronization/RazorDidSaveTextDocumentEndpoint.cs

@@ -18,9 +18,9 @@ internal class RazorDidSaveTextDocumentEndpoint : IVSDidSaveTextDocumentEndpoint
         return request.TextDocument;
     }
 
-    public Task HandleNotificationAsync(DidSaveTextDocumentParams request, RazorRequestContext context, CancellationToken cancellationToken)
+    public Task HandleNotificationAsync(DidSaveTextDocumentParams request, RazorRequestContext requestContext, CancellationToken cancellationToken)
     {
-        context.LspLogger.LogInformation($"Saved Document {request.TextDocument.Uri.GetAbsoluteOrUNCPath()}");
+        requestContext.LspLogger.LogInformation($"Saved Document {request.TextDocument.Uri.GetAbsoluteOrUNCPath()}");
 
         return Task.CompletedTask;
     }

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/EndpointContracts/IValidateBreakpointRangeEndpoint.cs

@@ -0,0 +1,14 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the MIT license. See License.txt in the project root for license information.
+
+using Microsoft.CommonLanguageServerProtocol.Framework;
+using Microsoft.VisualStudio.LanguageServer.Protocol;
+
+namespace Microsoft.AspNetCore.Razor.LanguageServer.EndpointContracts
+{
+    [LanguageServerEndpoint(VSInternalMethods.TextDocumentValidateBreakableRangeName)]
+    internal interface IValidateBreakpointRangeEndpoint : IRazorRequestHandler<ValidateBreakpointRangeParamsBridge, Range?>,
+        IRegistrationExtension
+    {
+    }
+}

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/EndpointContracts/RazorDiagnosticsParams.cs

@@ -10,10 +10,10 @@ namespace Microsoft.AspNetCore.Razor.LanguageServer.EndpointContracts
     // Note: This type should be kept in sync with the one in VisualStudio.LanguageServerClient assembly.
     internal class RazorDiagnosticsParams
     {
-        public RazorLanguageKind Kind { get; set; }
+        public RazorLanguageKind Kind { get; init; }
 
-        public required Uri RazorDocumentUri { get; set; }
+        public required Uri RazorDocumentUri { get; init; }
 
-        public required VSDiagnostic[] Diagnostics { get; set; }
+        public required VSDiagnostic[] Diagnostics { get; init; }
     }
 }

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/EndpointContracts/RazorDiagnosticsResponse.cs

@@ -8,8 +8,8 @@ namespace Microsoft.AspNetCore.Razor.LanguageServer.EndpointContracts
     // Note: This type should be kept in sync with the one in VisualStudio.LanguageServerClient assembly.
     internal class RazorDiagnosticsResponse
     {
-        public VSDiagnostic[]? Diagnostics { get; set; }
+        public VSDiagnostic[]? Diagnostics { get; init; }
 
-        public int? HostDocumentVersion { get; set; }
+        public int? HostDocumentVersion { get; init; }
     }
 }

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/EndpointContracts/RazorLanguageQueryParams.cs

@@ -2,14 +2,18 @@
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
 using System;
+using System.Runtime.Serialization;
 using Microsoft.VisualStudio.LanguageServer.Protocol;
 
 namespace Microsoft.AspNetCore.Razor.LanguageServer.EndpointContracts
 {
+    [DataContract]
     internal class RazorLanguageQueryParams
     {
+        [DataMember(Name = "uri")]
         public required Uri Uri { get; set; }
 
+        [DataMember(Name ="position")]
         public required Position Position { get; set; }
     }
 }

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/EndpointContracts/RazorMapToDocumentEditsParams.cs

@@ -2,21 +2,29 @@
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
 using System;
+using System.Runtime.Serialization;
 using Microsoft.AspNetCore.Razor.LanguageServer.Protocol;
 using Microsoft.VisualStudio.LanguageServer.Protocol;
 
 namespace Microsoft.AspNetCore.Razor.LanguageServer.EndpointContracts
 {
+    // Note: This type should be kept in sync with the one in Razor.HtmlCSharp assembly.
+    [DataContract]
     internal class RazorMapToDocumentEditsParams
     {
-        public RazorLanguageKind Kind { get; set; }
+        [DataMember(Name = "kind")]
+        public RazorLanguageKind Kind { get; init; }
 
-        public required Uri RazorDocumentUri { get; set; }
+        [DataMember(Name = "razorDocumentUri")]
+        public required Uri RazorDocumentUri { get; init; }
 
-        public required TextEdit[] ProjectedTextEdits { get; set; }
+        [DataMember(Name = "projectedTextEdits")]
+        public required TextEdit[] ProjectedTextEdits { get; init; }
 
-        public TextEditKind TextEditKind { get; set; }
+        [DataMember(Name = "textEditKind")]
+        public TextEditKind TextEditKind { get; init; }
 
-        public required FormattingOptions FormattingOptions { get; set; }
+        [DataMember(Name = "formattingOptions")]
+        public required FormattingOptions FormattingOptions { get; init; }
     }
 }

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/EndpointContracts/RazorMapToDocumentEditsResponse.cs

@@ -1,14 +1,18 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
+using System.Runtime.Serialization;
 using Microsoft.VisualStudio.LanguageServer.Protocol;
 
 namespace Microsoft.AspNetCore.Razor.LanguageServer.EndpointContracts
 {
+    [DataContract]
     internal class RazorMapToDocumentEditsResponse
     {
-        public required TextEdit[] TextEdits { get; set; }
+        [DataMember(Name = "textEdits")]
+        public required TextEdit[] TextEdits { get; init; }
 
-        public int? HostDocumentVersion { get; set; }
+        [DataMember(Name = "hostDocumentVersion")]
+        public int? HostDocumentVersion { get; init; }
     }
 }

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/EndpointContracts/RazorMapToDocumentRangesParams.cs

@@ -2,19 +2,25 @@
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
 using System;
+using System.Runtime.Serialization;
 using Microsoft.AspNetCore.Razor.LanguageServer.Protocol;
 
 namespace Microsoft.AspNetCore.Razor.LanguageServer.EndpointContracts
 {
     // Note: This type should be kept in sync with the one in VisualStudio.LanguageServerClient assembly.
+    [DataContract]
     internal class RazorMapToDocumentRangesParams
     {
-        public RazorLanguageKind Kind { get; set; }
+        [DataMember(Name = "kind")]
+        public RazorLanguageKind Kind { get; init; }
 
-        public required Uri RazorDocumentUri { get; set; }
+        [DataMember(Name = "razorDocumentUri")]
+        public required Uri RazorDocumentUri { get; init; }
 
-        public required Range[] ProjectedRanges { get; set; }
+        [DataMember(Name = "projectedRanges")]
+        public required Range[] ProjectedRanges { get; init; }
 
-        public MappingBehavior MappingBehavior { get; set; }
+        [DataMember(Name = "mappingBehavior")]
+        public MappingBehavior MappingBehavior { get; init; }
     }
 }

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/EndpointContracts/RazorMapToDocumentRangesResponse.cs

@@ -1,14 +1,19 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
+using System.Runtime.Serialization;
+
 namespace Microsoft.AspNetCore.Razor.LanguageServer.EndpointContracts
 {
     // NOTE: Changes here MUST be copied over to
     // Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp.RazorMapToDocumentRangesResponse
+    [DataContract]
     internal class RazorMapToDocumentRangesResponse
     {
-        public required Range[] Ranges { get; set; }
+        [DataMember(Name = "ranges")]
+        public required Range[] Ranges { get; init; }
 
-        public int? HostDocumentVersion { get; set; }
+        [DataMember(Name = "hostDocumentVersion")]
+        public int? HostDocumentVersion { get; init; }
     }
 }

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/EndpointContracts/ValidateBreakpointRangeParamsBridge.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;
+using Microsoft.VisualStudio.LanguageServer.Protocol;
+
+namespace Microsoft.AspNetCore.Razor.LanguageServer.EndpointContracts
+{
+    internal class ValidateBreakpointRangeParamsBridge : VSInternalValidateBreakableRangeParams, ITextDocumentPositionParams
+    {
+        public Position Position
+        {
+            get { return Range.Start; }
+            set { throw new NotImplementedException(); }
+        }
+    }
+}

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/Extensions/IServiceCollectionExtensions.cs

@@ -7,6 +7,7 @@ using Microsoft.AspNetCore.Razor.LanguageServer.Common;
 using Microsoft.AspNetCore.Razor.LanguageServer.Completion;
 using Microsoft.AspNetCore.Razor.LanguageServer.Completion.Delegation;
 using Microsoft.AspNetCore.Razor.LanguageServer.DocumentPresentation;
+using Microsoft.AspNetCore.Razor.LanguageServer.DocumentSynchronization;
 using Microsoft.AspNetCore.Razor.LanguageServer.EndpointContracts;
 using Microsoft.AspNetCore.Razor.LanguageServer.Formatting;
 using Microsoft.AspNetCore.Razor.LanguageServer.Hover;
@@ -22,8 +23,6 @@ using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Options;
 using Microsoft.VisualStudio.Editor.Razor;
 using Microsoft.VisualStudio.LanguageServer.Protocol;
-using StreamJsonRpc;
-using Microsoft.AspNetCore.Razor.LanguageServer.DocumentSynchronization;
 
 namespace Microsoft.AspNetCore.Razor.LanguageServer.Extensions;
 
@@ -42,6 +41,8 @@ internal static class IServiceCollectionExtensions
         services.AddSingleton<IInitializeManager<InitializeParams, InitializeResult>, CapabilitiesManager>();
         services.AddSingleton<IRequestContextFactory<RazorRequestContext>, RazorRequestContextFactory>();
 
+        services.AddSingleton<IRegistrationExtension, RazorLanguageServerCapability>();
+
         services.AddSingleton<IOnInitialized>(serverManager);
     }
 
@@ -145,7 +146,9 @@ internal static class IServiceCollectionExtensions
         services.AddHandler<RazorDidOpenTextDocumentEndpoint>();
         services.AddHandler<RazorDidSaveTextDocumentEndpoint>();
 
+        services.AddHandler<RazorMapToDocumentEditsEndpoint>();
         services.AddHandler<RazorMapToDocumentRangesEndpoint>();
+        services.AddHandler<RazorLanguageQueryEndpoint>();
     }
 
     public static void AddOptionsServices(this IServiceCollection services)

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/Hover/RazorHoverEndpoint.cs

@@ -45,23 +45,20 @@ namespace Microsoft.AspNetCore.Razor.LanguageServer.Hover
             return new RegistrationExtensionResult(AssociatedServerCapability, new SumType<bool, HoverOptions>(registrationOptions));
         }
 
-        /// <inheritdoc/>
         protected override string CustomMessageTarget => RazorLanguageServerCustomMessageTargets.RazorHoverEndpointName;
 
-        /// <inheritdoc/>
-        protected override IDelegatedParams CreateDelegatedParams(TextDocumentPositionParamsBridge request, RazorRequestContext razorRequestContext, Projection projection, CancellationToken cancellationToken)
+        protected override Task<IDelegatedParams?> CreateDelegatedParamsAsync(TextDocumentPositionParamsBridge request, RazorRequestContext requestContext, Projection projection, CancellationToken cancellationToken)
         {
-            var documentContext = razorRequestContext.GetRequiredDocumentContext();
-            return new DelegatedPositionParams(
+            var documentContext = requestContext.GetRequiredDocumentContext();
+            return Task.FromResult<IDelegatedParams?>(new DelegatedPositionParams(
                     documentContext.Identifier,
                     projection.Position,
-                    projection.LanguageKind);
+                    projection.LanguageKind));
         }
 
-        /// <inheritdoc/>
-        protected override async Task<VSInternalHover?> TryHandleAsync(TextDocumentPositionParamsBridge request, RazorRequestContext razorRequestContext, Projection projection, CancellationToken cancellationToken)
+        protected override async Task<VSInternalHover?> TryHandleAsync(TextDocumentPositionParamsBridge request, RazorRequestContext requestContext, Projection projection, CancellationToken cancellationToken)
         {
-            var documentContext = razorRequestContext.GetRequiredDocumentContext();
+            var documentContext = requestContext.GetRequiredDocumentContext();
             // HTML can still sometimes be handled by razor. For example hovering over
             // a component tag like <Counter /> will still be in an html context
             if (projection.LanguageKind == RazorLanguageKind.CSharp)
@@ -75,15 +72,14 @@ namespace Microsoft.AspNetCore.Razor.LanguageServer.Hover
             return _hoverInfoService.GetHoverInfo(codeDocument, location, _clientCapabilities!);
         }
 
-        /// <inheritdoc/>
-        protected override async Task<VSInternalHover?> HandleDelegatedResponseAsync(VSInternalHover? response, TextDocumentPositionParamsBridge originalRequest, RazorRequestContext razorRequestContext, Projection projection, CancellationToken cancellationToken)
+        protected override async Task<VSInternalHover?> HandleDelegatedResponseAsync(VSInternalHover? response, TextDocumentPositionParamsBridge originalRequest, RazorRequestContext requestContext, Projection projection, CancellationToken cancellationToken)
         {
             if (response?.Range is null)
             {
                 return response;
             }
 
-            var documentContext = razorRequestContext.GetRequiredDocumentContext();
+            var documentContext = requestContext.GetRequiredDocumentContext();
             var codeDocument = await documentContext.GetCodeDocumentAsync(cancellationToken).ConfigureAwait(false);
 
             if (_documentMappingService.TryMapFromProjectedDocumentRange(codeDocument, response.Range, out var projectedRange))

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/Implementation/ImplementationEndpoint.cs

@@ -40,13 +40,13 @@ namespace Microsoft.AspNetCore.Razor.LanguageServer.Implementation
             return new RegistrationExtensionResult(ServerCapability, option);
         }
 
-        protected override IDelegatedParams CreateDelegatedParams(TextDocumentPositionParamsBridge request, RazorRequestContext requestContext, Projection projection, CancellationToken cancellationToken)
+        protected override Task<IDelegatedParams?> CreateDelegatedParamsAsync(TextDocumentPositionParamsBridge request, RazorRequestContext requestContext, Projection projection, CancellationToken cancellationToken)
         {
             var documentContext = requestContext.GetRequiredDocumentContext();
-            return new DelegatedPositionParams(
+            return Task.FromResult<IDelegatedParams?>(new DelegatedPositionParams(
                     documentContext.Identifier,
                     projection.Position,
-                    projection.LanguageKind);
+                    projection.LanguageKind));
         }
 
         protected async override Task<ImplementationResult> HandleDelegatedResponseAsync(ImplementationResult delegatedResponse, TextDocumentPositionParamsBridge request, RazorRequestContext requestContext, Projection projection, CancellationToken cancellationToken)

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/RazorConfigurationEndpoint.cs

@@ -26,9 +26,9 @@ namespace Microsoft.AspNetCore.Razor.LanguageServer
 
         public bool MutatesSolutionState => true;
 
-        public async Task HandleNotificationAsync(DidChangeConfigurationParams request, RazorRequestContext context, CancellationToken cancellationToken)
+        public async Task HandleNotificationAsync(DidChangeConfigurationParams request, RazorRequestContext requestContext, CancellationToken cancellationToken)
         {
-            context.Logger.LogInformation("Settings changed. Updating the server.");
+            requestContext.Logger.LogInformation("Settings changed. Updating the server.");
 
             await _optionsMonitor.UpdateAsync(cancellationToken);
         }

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/RazorInitializeEndpoint.cs

@@ -14,9 +14,9 @@ internal class RazorInitializeEndpoint : IRazorDocumentlessRequestHandler<Initia
 {
     public bool MutatesSolutionState { get; } = true;
 
-    public Task<InitializeResult> HandleRequestAsync(InitializeParams request, RazorRequestContext context, CancellationToken cancellationToken)
+    public Task<InitializeResult> HandleRequestAsync(InitializeParams request, RazorRequestContext requestContext, CancellationToken cancellationToken)
     {
-        var capabilitiesManager = context.GetRequiredService<IInitializeManager<InitializeParams, InitializeResult>>();
+        var capabilitiesManager = requestContext.GetRequiredService<IInitializeManager<InitializeParams, InitializeResult>>();
 
         capabilitiesManager.SetInitializeParams(request);
         var serverCapabilities = capabilitiesManager.GetInitializeResult();

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/RazorLanguageQueryResponse.cs

@@ -1,19 +1,25 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
+using System.Runtime.Serialization;
 using Microsoft.AspNetCore.Razor.LanguageServer.Protocol;
 using Microsoft.VisualStudio.LanguageServer.Protocol;
 
 namespace Microsoft.AspNetCore.Razor.LanguageServer
 {
+    [DataContract]
     internal class RazorLanguageQueryResponse
     {
+        [DataMember(Name = "kind")]
         public RazorLanguageKind Kind { get; set; }
 
+        [DataMember(Name = "positionIndex")]
         public int PositionIndex { get; set; }
 
+        [DataMember(Name = "position")]
         public required Position Position { get; set; }
 
+        [DataMember(Name = "hostDocumentVersion")]
         public int? HostDocumentVersion { get; set; }
     }
 }

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/RazorLanguageServer.cs

@@ -20,6 +20,7 @@ using Microsoft.CodeAnalysis.Razor;
 using Microsoft.CodeAnalysis.Razor.Workspaces;
 using Microsoft.CommonLanguageServerProtocol.Framework;
 using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.DependencyInjection.Extensions;
 using Microsoft.Extensions.Logging;
 using Microsoft.VisualStudio.Editor.Razor;
 using Microsoft.VisualStudio.Telemetry;
@@ -122,6 +123,9 @@ internal class RazorLanguageServer : AbstractLanguageServer<RazorRequestContext>
         services.AddSingleton<ITelemetryReporter>(provider =>
             new TelemetryReporter(ImmutableArray.Create(TelemetryService.DefaultSession), provider.GetRequiredService<ILoggerFactory>()));
 
+        // Defaults: For when the caller hasn't provided them through the `configure` action.
+        services.TryAddSingleton<HostServicesProvider, DefaultHostServicesProvider>();
+
         AddHandlers(services);
 
         var lspServices = new LspServices(services);
@@ -142,6 +146,7 @@ internal class RazorLanguageServer : AbstractLanguageServer<RazorRequestContext>
             services.AddHandler<RazorProximityExpressionsEndpoint>();
             services.AddRegisteringHandler<DocumentColorEndpoint>();
             services.AddRegisteringHandler<FoldingRangeEndpoint>();
+            services.AddRegisteringHandler<ValidateBreakpointRangeEndpoint>();
         }
     }
 

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/RazorLanguageServerCapability.cs

@@ -1,39 +1,35 @@
 // 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.Generic;
 using System.Diagnostics.CodeAnalysis;
 using Microsoft.VisualStudio.LanguageServer.Protocol;
 using Newtonsoft.Json.Linq;
 
 namespace Microsoft.AspNetCore.Razor.LanguageServer
 {
-    internal record RazorLanguageServerCapability(
-        bool LanguageQuery,
-        bool RangeMapping,
-        bool EditMapping,
-        bool MonitorProjectConfigurationFilePath,
-        bool BreakpointSpan,
-        bool ProximityExpressions)
+    internal class RazorLanguageServerCapability : IRegistrationExtension
     {
         private const string RazorCapabilityKey = "razor";
-        private static readonly RazorLanguageServerCapability s_default = new RazorLanguageServerCapability(
-            LanguageQuery: true,
-            RangeMapping: true,
-            EditMapping: true,
-            MonitorProjectConfigurationFilePath: true,
-            BreakpointSpan: true,
-            ProximityExpressions: true);
-
-        public static void AddTo(ServerCapabilities capabilities)
+        private static readonly RazorLanguageServerCapability s_default = new RazorLanguageServerCapability
         {
-            // We have to use the experimental capabilities bucket here because not all platforms maintain custom capabilities. For instance
-            // in Visual Studio scenarios it will deserialize server capabilties into what it believes is "valid" and then will re-pass said
-            // server capabilities to our client side code having lost the information of the custom capabilities. To avoid this we use the
-            // experimental bag since it's part of the official LSP spec. This approach enables us to work with any client.
-            capabilities.Experimental ??= new Dictionary<string, JToken> {
-                { RazorCapabilityKey, JToken.FromObject(s_default) }
-            };
+            LanguageQuery = true,
+            RangeMapping = true,
+            EditMapping = true,
+            MonitorProjectConfigurationFilePath = true,
+            BreakpointSpan = true,
+            ProximityExpressions = true
+        };
+
+        public bool LanguageQuery { get; set; }
+        public bool RangeMapping { get; set; }
+        public bool EditMapping { get; set; }
+        public bool MonitorProjectConfigurationFilePath { get; set; }
+        public bool BreakpointSpan { get; set; }
+        public bool ProximityExpressions { get; set; }
+
+        public RegistrationExtensionResult GetRegistration(VSInternalClientCapabilities clientCapabilities)
+        {
+            return new RegistrationExtensionResult(RazorCapabilityKey, JToken.FromObject(s_default));
         }
 
         public static bool TryGet(JToken token, [NotNullWhen(true)] out RazorLanguageServerCapability? razorCapability)

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/RazorLanguageServerWrapper.cs

@@ -10,6 +10,7 @@ using Microsoft.CodeAnalysis.Razor.Workspaces;
 using Microsoft.CommonLanguageServerProtocol.Framework;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.VisualStudio.LanguageServer.Protocol;
+using Newtonsoft.Json.Serialization;
 using StreamJsonRpc;
 
 namespace Microsoft.AspNetCore.Razor.LanguageServer;
@@ -72,6 +73,7 @@ internal sealed class RazorLanguageServerWrapper : IAsyncDisposable
         var messageFormatter = new JsonMessageFormatter();
         messageFormatter.JsonSerializer.AddVSInternalExtensionConverters();
         messageFormatter.JsonSerializer.Converters.RegisterRazorConverters();
+        messageFormatter.JsonSerializer.ContractResolver = new CamelCasePropertyNamesContractResolver();
 
         var jsonRpc = new JsonRpc(new HeaderDelimitedMessageHandler(output, input, messageFormatter));
 

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/Refactoring/RenameEndpoint.cs

@@ -63,10 +63,8 @@ namespace Microsoft.AspNetCore.Razor.LanguageServer.Refactoring
             return new RegistrationExtensionResult(ServerCapability, new SumType<bool, RenameOptions>(options));
         }
 
-        /// <inheritdoc/>
         protected override string CustomMessageTarget => RazorLanguageServerCustomMessageTargets.RazorRenameEndpointName;
 
-        /// <inheritdoc/>
         protected override async Task<WorkspaceEdit?> TryHandleAsync(RenameParamsBridge request, RazorRequestContext requestContext, Projection projection, CancellationToken cancellationToken)
         {
             var documentContext = requestContext.GetRequiredDocumentContext();
@@ -88,18 +86,16 @@ namespace Microsoft.AspNetCore.Razor.LanguageServer.Refactoring
         protected override bool IsSupported()
             => _languageServerFeatureOptions.SupportsFileManipulation;
 
-        /// <inheritdoc/>
-        protected override IDelegatedParams CreateDelegatedParams(RenameParamsBridge request, RazorRequestContext requestContext, Projection projection, CancellationToken cancellationToken)
+        protected override Task<IDelegatedParams?> CreateDelegatedParamsAsync(RenameParamsBridge request, RazorRequestContext requestContext, Projection projection, CancellationToken cancellationToken)
         {
             var documentContext = requestContext.GetRequiredDocumentContext();
-            return new DelegatedRenameParams(
+            return Task.FromResult<IDelegatedParams?>(new DelegatedRenameParams(
                     documentContext.Identifier,
                     projection.Position,
                     projection.LanguageKind,
-                    request.NewName);
+                    request.NewName));
         }
 
-        /// <inheritdoc/>
         protected override async Task<WorkspaceEdit?> HandleDelegatedResponseAsync(WorkspaceEdit? response, RenameParamsBridge request, RazorRequestContext reqeuestContext, Projection projection, CancellationToken cancellationToken)
         {
             if (response is null)

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/Semantic/RazorSemanticTokensEndpoint.cs

@@ -20,20 +20,20 @@ namespace Microsoft.AspNetCore.Razor.LanguageServer.Semantic
         {
         }
 
-        public async Task<SemanticTokens?> HandleRequestAsync(SemanticTokensRangeParams request, RazorRequestContext context, CancellationToken cancellationToken)
+        public async Task<SemanticTokens?> HandleRequestAsync(SemanticTokensRangeParams request, RazorRequestContext requestContext, CancellationToken cancellationToken)
         {
             if (request is null)
             {
                 throw new ArgumentNullException(nameof(request));
             }
 
-            var documentContext = context.GetRequiredDocumentContext();
-            var semanticTokensInfoService = context.GetRequiredService<RazorSemanticTokensInfoService>();
+            var documentContext = requestContext.GetRequiredDocumentContext();
+            var semanticTokensInfoService = requestContext.GetRequiredService<RazorSemanticTokensInfoService>();
 
             var semanticTokens = await semanticTokensInfoService.GetSemanticTokensAsync(request.TextDocument, request.Range, documentContext, cancellationToken);
             var amount = semanticTokens is null ? "no" : (semanticTokens.Data.Length / 5).ToString(Thread.CurrentThread.CurrentCulture);
 
-            context.Logger.LogInformation("Returned {amount} semantic tokens for range {request.Range} in {request.TextDocument.Uri}.", amount, request.Range, request.TextDocument.Uri);
+            requestContext.Logger.LogInformation("Returned {amount} semantic tokens for range {request.Range} in {request.TextDocument.Uri}.", amount, request.Range, request.TextDocument.Uri);
 
             if (semanticTokens is not null)
             {

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/Semantic/SemanticTokensRefreshEndpoint.cs

@@ -25,7 +25,7 @@ namespace Microsoft.AspNetCore.Razor.LanguageServer.Semantic
             _semanticTokensRefreshPublisher = semanticTokensRefreshPublisher;
         }
 
-        public Task HandleNotificationAsync(SemanticTokensRefreshParams request, RazorRequestContext context, CancellationToken cancellationToken)
+        public Task HandleNotificationAsync(SemanticTokensRefreshParams request, RazorRequestContext requestContext, CancellationToken cancellationToken)
         {
             // We have to invalidate the tokens cache since it may no longer be up to date.
             _semanticTokensRefreshPublisher.EnqueueWorkspaceSemanticTokensRefresh();

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/SignatureHelp/SignatureHelpEndpoint.cs

@@ -2,6 +2,7 @@
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
 using System.Threading;
+using System.Threading.Tasks;
 using Microsoft.AspNetCore.Razor.LanguageServer.Common;
 using Microsoft.AspNetCore.Razor.LanguageServer.EndpointContracts;
 using Microsoft.AspNetCore.Razor.LanguageServer.Protocol;
@@ -23,7 +24,6 @@ namespace Microsoft.AspNetCore.Razor.LanguageServer.SignatureHelp
         {
         }
 
-        /// <inheritdoc />
         protected override string CustomMessageTarget => RazorLanguageServerCustomMessageTargets.RazorSignatureHelpEndpointName;
 
         public RegistrationExtensionResult GetRegistration(VSInternalClientCapabilities clientCapabilities)
@@ -38,14 +38,13 @@ namespace Microsoft.AspNetCore.Razor.LanguageServer.SignatureHelp
             return new RegistrationExtensionResult(ServerCapability, option);
         }
 
-        /// <inheritdoc />
-        protected override IDelegatedParams CreateDelegatedParams(SignatureHelpParamsBridge request, RazorRequestContext requestContext, Projection projection, CancellationToken cancellationToken)
+        protected override Task<IDelegatedParams?> CreateDelegatedParamsAsync(SignatureHelpParamsBridge request, RazorRequestContext requestContext, Projection projection, CancellationToken cancellationToken)
         {
             var documentContext = requestContext.GetRequiredDocumentContext();
-            return new DelegatedPositionParams(
+            return Task.FromResult<IDelegatedParams?>(new DelegatedPositionParams(
                     documentContext.Identifier,
                     projection.Position,
-                    projection.LanguageKind);
+                    projection.LanguageKind));
         }
     }
 }

src/Razor/src/Microsoft.AspNetCore.Razor.OmniSharpPlugin.StrongNamed/OmniSharpDocumentSnapshot.cs

@@ -4,7 +4,6 @@
 #nullable disable
 
 using System;
-using Microsoft.AspNetCore.Razor.Language;
 using Microsoft.CodeAnalysis.Razor.ProjectSystem;
 
 namespace Microsoft.AspNetCore.Razor.OmniSharpPlugin

src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/ProjectSystem/DocumentState.cs

@@ -465,12 +465,10 @@ namespace Microsoft.CodeAnalysis.Razor.ProjectSystem
                     }
                 }
 
-                RazorCodeDocument? olderOutput = null;
                 if (_older?._taskUnsafeReference != null &&
                     _older._taskUnsafeReference.TryGetTarget(out var taskUnsafe))
                 {
-                    VersionStamp olderInputVersion;
-                    (olderOutput, olderInputVersion) = await taskUnsafe.ConfigureAwait(false);
+                    var (olderOutput, olderInputVersion) = await taskUnsafe.ConfigureAwait(false);
                     if (inputVersion.GetNewerVersion(olderInputVersion) == olderInputVersion)
                     {
                         // Nothing has changed, we can use the cached result.

src/Razor/src/Microsoft.VisualStudio.LanguageServer.ContainedLanguage/DefaultFallbackCapabilitiesFilterResolver.cs

@@ -1,8 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System;
 using System.ComponentModel.Composition;
 using Microsoft.VisualStudio.LanguageServer.Protocol;
@@ -20,75 +18,40 @@ namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage
                 throw new ArgumentNullException(nameof(lspRequestMethodName));
             }
 
-            switch (lspRequestMethodName)
+            return lspRequestMethodName switch
             {
                 // Standard LSP capabilities
-                case Methods.TextDocumentImplementationName:
-                    return CheckImplementationCapabilities;
-                case Methods.TextDocumentTypeDefinitionName:
-                    return CheckTypeDefinitionCapabilities;
-                case Methods.TextDocumentReferencesName:
-                    return CheckFindAllReferencesCapabilities;
-                case Methods.TextDocumentRenameName:
-                    return CheckRenameCapabilities;
-                case Methods.TextDocumentSignatureHelpName:
-                    return CheckSignatureHelpCapabilities;
-                case Methods.TextDocumentWillSaveName:
-                    return CheckWillSaveCapabilities;
-                case Methods.TextDocumentWillSaveWaitUntilName:
-                    return CheckWillSaveWaitUntilCapabilities;
-                case Methods.TextDocumentRangeFormattingName:
-                    return CheckRangeFormattingCapabilities;
-                case Methods.WorkspaceSymbolName:
-                    return CheckWorkspaceSymbolCapabilities;
-                case Methods.TextDocumentOnTypeFormattingName:
-                    return CheckOnTypeFormattingCapabilities;
-                case Methods.TextDocumentFormattingName:
-                    return CheckFormattingCapabilities;
-                case Methods.TextDocumentHoverName:
-                    return CheckHoverCapabilities;
-                case Methods.TextDocumentCodeActionName:
-                    return CheckCodeActionCapabilities;
-                case Methods.TextDocumentCodeLensName:
-                    return CheckCodeLensCapabilities;
-                case Methods.TextDocumentCompletionName:
-                    return CheckCompletionCapabilities;
-                case Methods.TextDocumentCompletionResolveName:
-                    return CheckCompletionResolveCapabilities;
-                case Methods.TextDocumentDefinitionName:
-                    return CheckDefinitionCapabilities;
-                case Methods.TextDocumentDocumentHighlightName:
-                    return CheckHighlightCapabilities;
-                case "textDocument/semanticTokens":
-                case Methods.TextDocumentSemanticTokensFullName:
-                case Methods.TextDocumentSemanticTokensFullDeltaName:
-                case Methods.TextDocumentSemanticTokensRangeName:
-                    return CheckSemanticTokensCapabilities;
-                case Methods.TextDocumentLinkedEditingRangeName:
-                    return CheckLinkedEditingRangeCapabilities;
-                case Methods.CodeActionResolveName:
-                    return CheckCodeActionResolveCapabilities;
-                case Methods.TextDocumentDocumentColorName:
-                    return CheckDocumentColorCapabilities;
-
+                Methods.TextDocumentImplementationName => CheckImplementationCapabilities,
+                Methods.TextDocumentTypeDefinitionName => CheckTypeDefinitionCapabilities,
+                Methods.TextDocumentReferencesName => CheckFindAllReferencesCapabilities,
+                Methods.TextDocumentRenameName => CheckRenameCapabilities,
+                Methods.TextDocumentSignatureHelpName => CheckSignatureHelpCapabilities,
+                Methods.TextDocumentWillSaveName => CheckWillSaveCapabilities,
+                Methods.TextDocumentWillSaveWaitUntilName => CheckWillSaveWaitUntilCapabilities,
+                Methods.TextDocumentRangeFormattingName => CheckRangeFormattingCapabilities,
+                Methods.WorkspaceSymbolName => CheckWorkspaceSymbolCapabilities,
+                Methods.TextDocumentOnTypeFormattingName => CheckOnTypeFormattingCapabilities,
+                Methods.TextDocumentFormattingName => CheckFormattingCapabilities,
+                Methods.TextDocumentHoverName => CheckHoverCapabilities,
+                Methods.TextDocumentCodeActionName => CheckCodeActionCapabilities,
+                Methods.TextDocumentCodeLensName => CheckCodeLensCapabilities,
+                Methods.TextDocumentCompletionName => CheckCompletionCapabilities,
+                Methods.TextDocumentCompletionResolveName => CheckCompletionResolveCapabilities,
+                Methods.TextDocumentDefinitionName => CheckDefinitionCapabilities,
+                Methods.TextDocumentDocumentHighlightName => CheckHighlightCapabilities,
+                "textDocument/semanticTokens" or Methods.TextDocumentSemanticTokensFullName or Methods.TextDocumentSemanticTokensFullDeltaName or Methods.TextDocumentSemanticTokensRangeName => CheckSemanticTokensCapabilities,
+                Methods.TextDocumentLinkedEditingRangeName => CheckLinkedEditingRangeCapabilities,
+                Methods.CodeActionResolveName => CheckCodeActionResolveCapabilities,
+                Methods.TextDocumentDocumentColorName => CheckDocumentColorCapabilities,
                 // VS LSP Expansion capabilities
-                case VSMethods.GetProjectContextsName:
-                    return CheckProjectContextsCapabilities;
-                case VSInternalMethods.DocumentReferencesName:
-                    return CheckMSReferencesCapabilities;
-                case VSInternalMethods.OnAutoInsertName:
-                    return CheckOnAutoInsertCapabilities;
-                case VSInternalMethods.DocumentPullDiagnosticName:
-                case VSInternalMethods.WorkspacePullDiagnosticName:
-                    return CheckPullDiagnosticCapabilities;
-                case VSInternalMethods.TextDocumentTextPresentationName:
-                    return CheckTextPresentationCapabilities;
-                case VSInternalMethods.TextDocumentUriPresentationName:
-                    return CheckUriPresentationCapabilities;
-
-                default:
-                    return FallbackCheckCapabilties;
-            }
+                VSMethods.GetProjectContextsName => CheckProjectContextsCapabilities,
+                VSInternalMethods.DocumentReferencesName => CheckMSReferencesCapabilities,
+                VSInternalMethods.OnAutoInsertName => CheckOnAutoInsertCapabilities,
+                VSInternalMethods.DocumentPullDiagnosticName or VSInternalMethods.WorkspacePullDiagnosticName => CheckPullDiagnosticCapabilities,
+                VSInternalMethods.TextDocumentTextPresentationName => CheckTextPresentationCapabilities,
+                VSInternalMethods.TextDocumentUriPresentationName => CheckUriPresentationCapabilities,
+                _ => FallbackCheckCapabilties,
+            };
         }
 
         private bool CheckDocumentColorCapabilities(JToken token)
@@ -97,14 +60,14 @@ namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage
 
             return serverCapabilities?.DocumentColorProvider?.Match(
                 boolValue => boolValue,
-                options => options != null) ?? false;
+                options => options is not null) ?? false;
         }
 
         private static bool CheckSemanticTokensCapabilities(JToken token)
         {
             var serverCapabilities = token.ToObject<VSServerCapabilities>();
 
-            return serverCapabilities?.SemanticTokensOptions != null;
+            return serverCapabilities?.SemanticTokensOptions is not null;
         }
 
         private static bool CheckImplementationCapabilities(JToken token)
@@ -113,7 +76,7 @@ namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage
 
             return serverCapabilities?.ImplementationProvider?.Match(
                 boolValue => boolValue,
-                options => options != null) ?? false;
+                options => options is not null) ?? false;
         }
 
         private bool CheckTypeDefinitionCapabilities(JToken token)
@@ -122,7 +85,7 @@ namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage
 
             return serverCapabilities?.TypeDefinitionProvider?.Match(
                 boolValue => boolValue,
-                options => options != null) ?? false;
+                options => options is not null) ?? false;
         }
 
         private static bool CheckFindAllReferencesCapabilities(JToken token)
@@ -131,7 +94,7 @@ namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage
 
             return serverCapabilities?.ReferencesProvider?.Match(
                 boolValue => boolValue,
-                options => options != null) ?? false;
+                options => options is not null) ?? false;
         }
 
         private static bool CheckRenameCapabilities(JToken token)
@@ -140,14 +103,14 @@ namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage
 
             return serverCapabilities?.RenameProvider?.Match(
                 boolValue => boolValue,
-                options => options != null) ?? false;
+                options => options is not null) ?? false;
         }
 
         private static bool CheckSignatureHelpCapabilities(JToken token)
         {
             var serverCapabilities = token.ToObject<ServerCapabilities>();
 
-            return serverCapabilities?.SignatureHelpProvider != null;
+            return serverCapabilities?.SignatureHelpProvider is not null;
         }
 
         private static bool CheckWillSaveCapabilities(JToken token)
@@ -170,7 +133,7 @@ namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage
 
             return serverCapabilities?.DocumentRangeFormattingProvider?.Match(
                 boolValue => boolValue,
-                options => options != null) ?? false;
+                options => options is not null) ?? false;
         }
 
         private static bool CheckWorkspaceSymbolCapabilities(JToken token)
@@ -179,14 +142,14 @@ namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage
 
             return serverCapabilities?.WorkspaceSymbolProvider?.Match(
                 boolValue => boolValue,
-                options => options != null) ?? false;
+                options => options is not null) ?? false;
         }
 
         private static bool CheckOnTypeFormattingCapabilities(JToken token)
         {
             var serverCapabilities = token.ToObject<ServerCapabilities>();
 
-            return serverCapabilities?.DocumentOnTypeFormattingProvider != null;
+            return serverCapabilities?.DocumentOnTypeFormattingProvider is not null;
         }
 
         private static bool CheckFormattingCapabilities(JToken token)
@@ -195,7 +158,7 @@ namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage
 
             return serverCapabilities?.DocumentFormattingProvider?.Match(
                 boolValue => boolValue,
-                options => options != null) ?? false;
+                options => options is not null) ?? false;
         }
 
         private static bool CheckHoverCapabilities(JToken token)
@@ -204,7 +167,7 @@ namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage
 
             return serverCapabilities?.HoverProvider?.Match(
                 boolValue => boolValue,
-                options => options != null) ?? false;
+                options => options is not null) ?? false;
         }
 
         private static bool CheckCodeActionCapabilities(JToken token)
@@ -213,21 +176,21 @@ namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage
 
             return serverCapabilities?.CodeActionProvider?.Match(
                 boolValue => boolValue,
-                options => options != null) ?? false;
+                options => options is not null) ?? false;
         }
 
         private static bool CheckCodeLensCapabilities(JToken token)
         {
             var serverCapabilities = token.ToObject<ServerCapabilities>();
 
-            return serverCapabilities?.CodeLensProvider != null;
+            return serverCapabilities?.CodeLensProvider is not null;
         }
 
         private static bool CheckCompletionCapabilities(JToken token)
         {
             var serverCapabilities = token.ToObject<ServerCapabilities>();
 
-            return serverCapabilities?.CompletionProvider != null;
+            return serverCapabilities?.CompletionProvider is not null;
         }
 
         private static bool CheckCompletionResolveCapabilities(JToken token)
@@ -243,7 +206,7 @@ namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage
 
             return serverCapabilities?.DefinitionProvider?.Match(
                 boolValue => boolValue,
-                options => options != null) ?? false;
+                options => options is not null) ?? false;
         }
 
         private static bool CheckHighlightCapabilities(JToken token)
@@ -252,7 +215,7 @@ namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage
 
             return serverCapabilities?.DocumentHighlightProvider?.Match(
                 boolValue => boolValue,
-                options => options != null) ?? false;
+                options => options is not null) ?? false;
         }
 
         private static bool CheckMSReferencesCapabilities(JToken token)
@@ -284,7 +247,7 @@ namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage
         {
             var serverCapabilities = token.ToObject<VSInternalServerCapabilities>();
 
-            return serverCapabilities?.OnAutoInsertProvider != null;
+            return serverCapabilities?.OnAutoInsertProvider is not null;
         }
 
         private static bool CheckTextPresentationCapabilities(JToken token)
@@ -306,7 +269,7 @@ namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage
 
             return serverCapabilities?.LinkedEditingRangeProvider?.Match(
               boolValue => boolValue,
-              options => options != null) ?? false;
+              options => options is not null) ?? false;
         }
 
         private static bool CheckPullDiagnosticCapabilities(JToken token)

src/Razor/src/Microsoft.VisualStudio.LanguageServer.ContainedLanguage/DefaultFileUriProvider.cs

@@ -1,10 +1,9 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System;
 using System.Composition;
+using System.Diagnostics.CodeAnalysis;
 using System.IO;
 using Microsoft.VisualStudio.Text;
 
@@ -71,14 +70,14 @@ namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage
             return uri;
         }
 
-        public override bool TryGet(ITextBuffer textBuffer, out Uri uri)
+        public override bool TryGet(ITextBuffer textBuffer, [NotNullWhen(returnValue: true)] out Uri? uri)
         {
             if (textBuffer is null)
             {
                 throw new ArgumentNullException(nameof(textBuffer));
             }
 
-            if (textBuffer.Properties.TryGetProperty(TextBufferUri, out uri))
+            if (textBuffer.Properties.TryGetProperty(TextBufferUri, out uri!))
             {
                 return true;
             }

src/Razor/src/Microsoft.VisualStudio.LanguageServer.ContainedLanguage/DefaultLSPDocument.cs

@@ -1,8 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System;
 using System.Collections.Generic;
 using Microsoft.VisualStudio.Text;
@@ -11,7 +9,7 @@ namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage
 {
     internal class DefaultLSPDocument : LSPDocument
     {
-        private LSPDocumentSnapshot _currentSnapshot;
+        private LSPDocumentSnapshot? _currentSnapshot;
 
         public DefaultLSPDocument(
             Uri uri,
@@ -54,7 +52,7 @@ namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage
                 {
                     // TextBuffer is tearing itself down, return last known snapshot to avoid generating
                     // a snapshot for an invalid TextBuffer
-                    return _currentSnapshot;
+                    return _currentSnapshot!;
                 }
 
                 if (_currentSnapshot?.Snapshot != TextBuffer.CurrentSnapshot)
@@ -66,7 +64,7 @@ namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage
             }
         }
 
-        public override LSPDocumentSnapshot UpdateVirtualDocument<TVirtualDocument>(IReadOnlyList<ITextChange> changes, int hostDocumentVersion, object state)
+        public override LSPDocumentSnapshot UpdateVirtualDocument<TVirtualDocument>(IReadOnlyList<ITextChange> changes, int hostDocumentVersion, object? state)
         {
             if (!TryGetVirtualDocument<TVirtualDocument>(out var virtualDocument))
             {

src/Razor/src/Microsoft.VisualStudio.LanguageServer.ContainedLanguage/DefaultLSPDocumentFactory.cs

@@ -1,8 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System;
 using System.Collections.Generic;
 using System.Composition;

src/Razor/src/Microsoft.VisualStudio.LanguageServer.ContainedLanguage/DefaultLSPDocumentManager.cs

@@ -1,13 +1,12 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Composition;
 using System.Diagnostics;
+using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using Microsoft.VisualStudio.Text;
 using Microsoft.VisualStudio.Threading;
@@ -125,7 +124,7 @@ namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage
             Uri hostDocumentUri,
             IReadOnlyList<ITextChange> changes,
             int hostDocumentVersion,
-            object state)
+            object? state)
         {
             if (hostDocumentUri is null)
             {
@@ -145,8 +144,7 @@ namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage
                 return;
             }
 
-            var virtualDocumentAcquired = lspDocument.TryGetVirtualDocument<TVirtualDocument>(out var virtualDocument);
-            if (!virtualDocumentAcquired)
+            if (!lspDocument.TryGetVirtualDocument<TVirtualDocument>(out var virtualDocument))
             {
                 // Unable to locate virtual document of typeof(TVirtualDocument)
                 // Ex. Microsoft.WebTools.Languages.LanguageServer.Delegation.ContainedLanguage.Css.CssVirtualDocument
@@ -179,7 +177,7 @@ namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage
             NotifyDocumentManagerChangeListeners(old, @new, oldVirtual, newVirtual, LSPDocumentChangeKind.VirtualDocumentChanged);
         }
 
-        public override bool TryGetDocument(Uri uri, out LSPDocumentSnapshot lspDocumentSnapshot)
+        public override bool TryGetDocument(Uri uri, [NotNullWhen(returnValue: true)] out LSPDocumentSnapshot? lspDocumentSnapshot)
         {
             if (!_documents.TryGetValue(uri, out var lspDocument))
             {
@@ -193,23 +191,23 @@ namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage
         }
 
         private void NotifyDocumentManagerChangeListeners(
-            LSPDocumentSnapshot old,
-            LSPDocumentSnapshot @new,
-            VirtualDocumentSnapshot virtualOld,
-            VirtualDocumentSnapshot virtualNew,
+            LSPDocumentSnapshot? old,
+            LSPDocumentSnapshot? @new,
+            VirtualDocumentSnapshot? virtualOld,
+            VirtualDocumentSnapshot? virtualNew,
             LSPDocumentChangeKind kind)
         {
             foreach (var listener in _documentManagerChangeListeners)
             {
                 var notifyListener = false;
 
-                if (old != null &&
-                    listener.Metadata.ContentTypes.Any(ct => old.Snapshot.ContentType.IsOfType(ct)))
+                if (old is not null &&
+                    listener.Metadata.ContentTypes.Any(old.Snapshot.ContentType.IsOfType))
                 {
                     notifyListener = true;
                 }
-                else if (@new != null &&
-                    listener.Metadata.ContentTypes.Any(ct => @new.Snapshot.ContentType.IsOfType(ct)))
+                else if (@new is not null &&
+                    listener.Metadata.ContentTypes.Any(@new.Snapshot.ContentType.IsOfType))
                 {
                     notifyListener = true;
                 }

src/Razor/src/Microsoft.VisualStudio.LanguageServer.ContainedLanguage/DefaultLSPDocumentSynchronizer.cs

@@ -1,8 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System;
 using System.Collections.Generic;
 using System.ComponentModel.Composition;
@@ -99,13 +97,13 @@ namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage
             }
         }
 
-        public override void Changed(LSPDocumentSnapshot old, LSPDocumentSnapshot @new, VirtualDocumentSnapshot virtualOld, VirtualDocumentSnapshot virtualNew, LSPDocumentChangeKind kind)
+        public override void Changed(LSPDocumentSnapshot? old, LSPDocumentSnapshot? @new, VirtualDocumentSnapshot? virtualOld, VirtualDocumentSnapshot? virtualNew, LSPDocumentChangeKind kind)
         {
             lock (_documentContextLock)
             {
                 if (kind == LSPDocumentChangeKind.Added)
                 {
-                    var lspDocument = @new;
+                    var lspDocument = @new!;
                     for (var i = 0; i < lspDocument.VirtualDocuments.Count; i++)
                     {
                         var virtualDocument = lspDocument.VirtualDocuments[i];
@@ -119,7 +117,7 @@ namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage
                 }
                 else if (kind == LSPDocumentChangeKind.Removed)
                 {
-                    var lspDocument = old;
+                    var lspDocument = old!;
                     for (var i = 0; i < lspDocument.VirtualDocuments.Count; i++)
                     {
                         var virtualDocument = lspDocument.VirtualDocuments[i];
@@ -139,7 +137,7 @@ namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage
                 }
                 else if (kind == LSPDocumentChangeKind.VirtualDocumentChanged)
                 {
-                    if (virtualOld.Snapshot.Version == virtualNew.Snapshot.Version)
+                    if (virtualOld!.Snapshot.Version == virtualNew!.Snapshot.Version)
                     {
                         // UpdateDocumentContextVersionInternal is typically invoked through a buffer notification,
                         //   however in the case where VirtualDocumentBase.Update is called with a zero change edit,

src/Razor/src/Microsoft.VisualStudio.LanguageServer.ContainedLanguage/Extensions/LSPDocumentManagerExtensions.cs

@@ -1,34 +0,0 @@
-// Copyright (c) .NET Foundation. All rights reserved.
-// Licensed under the MIT license. See License.txt in the project root for license information.
-
-#nullable disable
-
-using System;
-using System.Runtime.InteropServices;
-
-namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage.Extensions
-{
-    internal static class LSPDocumentManagerExtensions
-    {
-        public static bool TryGetDocument(this LSPDocumentManager documentManager, string filePath, out LSPDocumentSnapshot lspDocumentSnapshot)
-        {
-            if (documentManager is null)
-            {
-                throw new ArgumentNullException(nameof(documentManager));
-            }
-
-            if (filePath is null)
-            {
-                throw new ArgumentNullException(nameof(filePath));
-            }
-
-            if (filePath.StartsWith("/", StringComparison.Ordinal) && RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
-            {
-                filePath = filePath.Substring(1);
-            }
-
-            var uri = new Uri(filePath, UriKind.Absolute);
-            return documentManager.TryGetDocument(uri, out lspDocumentSnapshot);
-        }
-    }
-}

src/Razor/src/Microsoft.VisualStudio.LanguageServer.ContainedLanguage/Extensions/TextBufferExtensions.cs

@@ -1,8 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System;
 using Microsoft.VisualStudio.Text;
 

src/Razor/src/Microsoft.VisualStudio.LanguageServer.ContainedLanguage/Extensions/UriExtensions.cs

@@ -1,8 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System;
 using System.Net;
 

src/Razor/src/Microsoft.VisualStudio.LanguageServer.ContainedLanguage/FallbackCapabilitiesFilterResolver.cs

@@ -1,8 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System;
 using Newtonsoft.Json.Linq;
 

src/Razor/src/Microsoft.VisualStudio.LanguageServer.ContainedLanguage/FileUriProvider.cs

@@ -1,9 +1,8 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System;
+using System.Diagnostics.CodeAnalysis;
 using Microsoft.VisualStudio.Text;
 
 namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage
@@ -29,7 +28,7 @@ namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage
         /// <param name="textBuffer">A text buffer</param>
         /// <param name="uri">A <see cref="Uri"/> that can be used to locate the provided <paramref name="textBuffer"/>.</param>
         /// <returns><c>true</c> if a Razor based <see cref="Uri"/> existed on the buffer, other wise <c>false</c>.</returns>
-        public abstract bool TryGet(ITextBuffer textBuffer, out Uri uri);
+        public abstract bool TryGet(ITextBuffer textBuffer, [NotNullWhen(returnValue: true)] out Uri? uri);
 
         /// <summary>
         /// Adds or updates the provided <paramref name="uri"/> for the given <paramref name="textBuffer"/> under a Razor property name.

src/Razor/src/Microsoft.VisualStudio.LanguageServer.ContainedLanguage/InertContentType.cs

@@ -1,8 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System;
 using System.Collections.Generic;
 using System.Linq;

src/Razor/src/Microsoft.VisualStudio.LanguageServer.ContainedLanguage/InviolableEditTag.cs

@@ -1,8 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using Microsoft.VisualStudio.Text;
 
 namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage

src/Razor/src/Microsoft.VisualStudio.LanguageServer.ContainedLanguage/LSPDocument.cs

@@ -1,8 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
@@ -22,9 +20,9 @@ namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage
 
         public abstract IReadOnlyList<VirtualDocument> VirtualDocuments { get; }
 
-        public abstract LSPDocumentSnapshot UpdateVirtualDocument<TVirtualDocument>(IReadOnlyList<ITextChange> changes, int hostDocumentVersion, object state) where TVirtualDocument : VirtualDocument;
+        public abstract LSPDocumentSnapshot UpdateVirtualDocument<TVirtualDocument>(IReadOnlyList<ITextChange> changes, int hostDocumentVersion, object? state) where TVirtualDocument : VirtualDocument;
 
-        public bool TryGetVirtualDocument<TVirtualDocument>(out TVirtualDocument virtualDocument) where TVirtualDocument : VirtualDocument
+        public bool TryGetVirtualDocument<TVirtualDocument>([NotNullWhen(returnValue: true)] out TVirtualDocument? virtualDocument) where TVirtualDocument : VirtualDocument
         {
             for (var i = 0; i < VirtualDocuments.Count; i++)
             {

src/Razor/src/Microsoft.VisualStudio.LanguageServer.ContainedLanguage/LSPDocumentChangeListener.cs

@@ -1,17 +1,15 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage
 {
     internal abstract class LSPDocumentChangeListener
     {
         public abstract void Changed(
-            LSPDocumentSnapshot old,
-            LSPDocumentSnapshot @new,
-            VirtualDocumentSnapshot virtualOld,
-            VirtualDocumentSnapshot virtualNew,
+            LSPDocumentSnapshot? old,
+            LSPDocumentSnapshot? @new,
+            VirtualDocumentSnapshot? virtualOld,
+            VirtualDocumentSnapshot? virtualNew,
             LSPDocumentChangeKind kind);
     }
 }

src/Razor/src/Microsoft.VisualStudio.LanguageServer.ContainedLanguage/LSPDocumentFactory.cs

@@ -1,8 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using Microsoft.VisualStudio.Text;
 
 namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage

src/Razor/src/Microsoft.VisualStudio.LanguageServer.ContainedLanguage/LSPDocumentManager.cs

@@ -1,14 +1,13 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System;
+using System.Diagnostics.CodeAnalysis;
 
 namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage
 {
     public abstract class LSPDocumentManager
     {
-        public abstract bool TryGetDocument(Uri uri, out LSPDocumentSnapshot lspDocumentSnapshot);
+        public abstract bool TryGetDocument(Uri uri, [NotNullWhen(returnValue: true)] out LSPDocumentSnapshot? lspDocumentSnapshot);
     }
 }

src/Razor/src/Microsoft.VisualStudio.LanguageServer.ContainedLanguage/LSPDocumentSnapshot.cs

@@ -1,10 +1,9 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System;
 using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
 using Microsoft.VisualStudio.Text;
 
 namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage
@@ -19,7 +18,7 @@ namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage
 
         public abstract IReadOnlyList<VirtualDocumentSnapshot> VirtualDocuments { get; }
 
-        public bool TryGetVirtualDocument<TVirtualDocument>(out TVirtualDocument virtualDocument) where TVirtualDocument : VirtualDocumentSnapshot
+        public bool TryGetVirtualDocument<TVirtualDocument>([NotNullWhen(returnValue: true)] out TVirtualDocument? virtualDocument) where TVirtualDocument : VirtualDocumentSnapshot
         {
             for (var i = 0; i < VirtualDocuments.Count; i++)
             {

src/Razor/src/Microsoft.VisualStudio.LanguageServer.ContainedLanguage/LSPDocumentSynchronizer.cs

@@ -1,8 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System;
 using System.Threading;
 using System.Threading.Tasks;

src/Razor/src/Microsoft.VisualStudio.LanguageServer.ContainedLanguage/Microsoft.VisualStudio.LanguageServer.ContainedLanguage.csproj

@@ -15,4 +15,8 @@
     <PackageReference Include="Microsoft.VisualStudio.LanguageServer.Client.Implementation" Version="$(MicrosoftVisualStudioLanguageServerClientImplementationPackageVersion)" />
   </ItemGroup>
 
+  <ItemGroup>
+    <ProjectReference Include="..\Microsoft.AspNetCore.Razor.Common\Microsoft.AspNetCore.Razor.Common.csproj" />
+  </ItemGroup>
+
 </Project>

src/Razor/src/Microsoft.VisualStudio.LanguageServer.ContainedLanguage/TrackingLSPDocumentManager.cs

@@ -1,8 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System;
 using System.Collections.Generic;
 using Microsoft.VisualStudio.Text;
@@ -19,6 +17,6 @@ namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage
             Uri hostDocumentUri,
             IReadOnlyList<ITextChange> changes,
             int hostDocumentVersion,
-            object state) where TVirtualDocument : VirtualDocument;
+            object? state) where TVirtualDocument : VirtualDocument;
     }
 }

src/Razor/src/Microsoft.VisualStudio.LanguageServer.ContainedLanguage/VirtualDocument.cs

@@ -1,8 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System;
 using System.Collections.Generic;
 using Microsoft.VisualStudio.Text;
@@ -19,7 +17,7 @@ namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage
 
         public abstract int HostDocumentVersion { get; }
 
-        public abstract VirtualDocumentSnapshot Update(IReadOnlyList<ITextChange> changes, int hostDocumentVersion, object state);
+        public abstract VirtualDocumentSnapshot Update(IReadOnlyList<ITextChange> changes, int hostDocumentVersion, object? state);
 
         public abstract void Dispose();
     }

src/Razor/src/Microsoft.VisualStudio.LanguageServer.ContainedLanguage/VirtualDocumentBase.cs

@@ -1,8 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
@@ -41,7 +39,7 @@ namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage
 
         public override VirtualDocumentSnapshot CurrentSnapshot => _currentSnapshot;
 
-        public override VirtualDocumentSnapshot Update(IReadOnlyList<ITextChange> changes, int hostDocumentVersion, object state)
+        public override VirtualDocumentSnapshot Update(IReadOnlyList<ITextChange> changes, int hostDocumentVersion, object? state)
         {
             if (changes is null)
             {
@@ -64,7 +62,7 @@ namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage
             return _currentSnapshot;
         }
 
-        protected abstract T GetUpdatedSnapshot(object state);
+        protected abstract T GetUpdatedSnapshot(object? state);
 
         [SuppressMessage("Usage", "CA1816:Dispose methods should call SuppressFinalize", Justification = "https://github.com/dotnet/roslyn-analyzers/issues/4801")]
         public override void Dispose()

src/Razor/src/Microsoft.VisualStudio.LanguageServer.ContainedLanguage/VirtualDocumentFactory.cs

@@ -1,8 +1,7 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
+using System.Diagnostics.CodeAnalysis;
 using Microsoft.VisualStudio.Text;
 
 namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage
@@ -21,6 +20,6 @@ namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage
         /// <param name="virtualDocument">The resultant <see cref="VirtualDocument"/> for the top-level <paramref name="hostDocumentBuffer"/>.</param>
         /// <returns><c>true</c> if a <see cref="VirtualDocument"/> could be created, <c>false</c> otherwise. A result of <c>false</c> typically indicates
         /// that a <see cref="VirtualDocumentFactory"/> was not meant to be called for the given <paramref name="hostDocumentBuffer"/>.</returns>
-        public abstract bool TryCreateFor(ITextBuffer hostDocumentBuffer, out VirtualDocument virtualDocument);
+        public abstract bool TryCreateFor(ITextBuffer hostDocumentBuffer, [NotNullWhen(returnValue: true)] out VirtualDocument? virtualDocument);
     }
 }

src/Razor/src/Microsoft.VisualStudio.LanguageServer.ContainedLanguage/VirtualDocumentFactoryBase.cs

@@ -1,10 +1,9 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System;
 using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
 using Microsoft.VisualStudio.LanguageServer.ContainedLanguage.Extensions;
 using Microsoft.VisualStudio.Text;
 using Microsoft.VisualStudio.Utilities;
@@ -60,7 +59,7 @@ namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage
 
         protected abstract IContentType LanguageContentType { get; }
 
-        public override bool TryCreateFor(ITextBuffer hostDocumentBuffer, out VirtualDocument virtualDocument)
+        public override bool TryCreateFor(ITextBuffer hostDocumentBuffer, [NotNullWhen(returnValue: true)] out VirtualDocument? virtualDocument)
         {
             if (hostDocumentBuffer is null)
             {
@@ -119,7 +118,7 @@ namespace Microsoft.VisualStudio.LanguageServer.ContainedLanguage
         /// <summary>
         /// Returns additional properties (if any) to set on the language text buffer prior to language server init
         /// </summary>
-        protected virtual IReadOnlyDictionary<object, object> LanguageBufferProperties => null;
+        protected virtual IReadOnlyDictionary<object, object>? LanguageBufferProperties => null;
 
         /// <summary>
         /// Returns supported host document content type name (i.e. host document content type for which this factory can create virtual documents)

src/Razor/src/Microsoft.VisualStudio.LanguageServer.ContainedLanguage/VirtualDocumentSnapshot.cs

@@ -1,8 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System;
 using Microsoft.VisualStudio.Text;
 

src/Razor/src/Microsoft.VisualStudio.LanguageServer.ContainedLanguage/VisualStudioTextChange.cs

@@ -1,8 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System;
 using Microsoft.VisualStudio.LanguageServer.Protocol;
 using Microsoft.VisualStudio.Text;

src/Razor/src/Microsoft.VisualStudio.LanguageServerClient.Razor/CSHTMLFilePathToContentTypeProvider.cs

@@ -1,8 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System.ComponentModel.Composition;
 using Microsoft.CodeAnalysis.Razor.Workspaces;
 using Microsoft.VisualStudio.Utilities;

src/Razor/src/Microsoft.VisualStudio.LanguageServerClient.Razor/CSharpDocumentExcerptService.cs

@@ -1,8 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System;
 using System.Threading;
 using System.Threading.Tasks;
@@ -101,7 +99,7 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor
             return new ExcerptResultInternal(excerptText, razorDocumentSpan, classifiedSpans.ToImmutable(), document, span);
         }
 
-        private async Task<ImmutableArray<ClassifiedSpan>.Builder> ClassifyPreviewAsync(
+        private static async Task<ImmutableArray<ClassifiedSpan>.Builder> ClassifyPreviewAsync(
             TextSpan razorSpan,
             TextSpan excerptSpan,
             TextSpan generatedSpan,

src/Razor/src/Microsoft.VisualStudio.LanguageServerClient.Razor/CSharpDocumentPropertiesService.cs

@@ -1,8 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using Microsoft.CodeAnalysis.ExternalAccess.Razor;
 
 namespace Microsoft.VisualStudio.LanguageServerClient.Razor
@@ -21,6 +19,6 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor
 
         public bool DesignTimeOnly => false;
 
-        public string DiagnosticsLspClientName => RoslynRazorLanguageServerClientName;
+        public string? DiagnosticsLspClientName => RoslynRazorLanguageServerClientName;
     }
 }

src/Razor/src/Microsoft.VisualStudio.LanguageServerClient.Razor/CSharpVirtualDocument.cs

@@ -1,8 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System;
 using Microsoft.VisualStudio.LanguageServer.ContainedLanguage;
 using Microsoft.VisualStudio.Text;
@@ -15,6 +13,6 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor
         {
         }
 
-        protected override CSharpVirtualDocumentSnapshot GetUpdatedSnapshot(object state) => new(Uri, TextBuffer.CurrentSnapshot, HostDocumentVersion);
+        protected override CSharpVirtualDocumentSnapshot GetUpdatedSnapshot(object? state) => new(Uri, TextBuffer.CurrentSnapshot, HostDocumentVersion);
     }
 }

src/Razor/src/Microsoft.VisualStudio.LanguageServerClient.Razor/CSharpVirtualDocumentFactory.cs

@@ -55,7 +55,7 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor
 
         protected override string HostDocumentContentTypeName => RazorConstants.RazorLSPContentTypeName;
         protected override string LanguageFileNameSuffix => _languageServerFeatureOptions.CSharpVirtualDocumentSuffix;
-        protected override IReadOnlyDictionary<object, object> LanguageBufferProperties => s_languageBufferProperties;
+        protected override IReadOnlyDictionary<object, object>? LanguageBufferProperties => s_languageBufferProperties;
         protected override VirtualDocument CreateVirtualDocument(Uri uri, ITextBuffer textBuffer) => new CSharpVirtualDocument(uri, textBuffer);
 
         private class RemoteContentDefinitionType : IContentType

src/Razor/src/Microsoft.VisualStudio.LanguageServerClient.Razor/CSharpVirtualDocumentPublisher.cs

@@ -43,7 +43,7 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor
         }
 
         // Internal for testing
-        public override void Changed(LSPDocumentSnapshot old, LSPDocumentSnapshot @new, VirtualDocumentSnapshot virtualOld, VirtualDocumentSnapshot virtualNew, LSPDocumentChangeKind kind)
+        public override void Changed(LSPDocumentSnapshot? old, LSPDocumentSnapshot? @new, VirtualDocumentSnapshot? virtualOld, VirtualDocumentSnapshot? virtualNew, LSPDocumentChangeKind kind)
         {
             // We need the below check to address a race condition between when a request is sent to the C# server
             // for a generated document and when the C# server receives a document/didOpen notification. This race
@@ -54,7 +54,7 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor
             // workaround until a longer-term solution is implemented in the future.
             if (kind == LSPDocumentChangeKind.Added && _dynamicFileInfoProvider is DefaultRazorDynamicFileInfoProvider defaultProvider)
             {
-                defaultProvider.PromoteBackgroundDocument(@new.Uri, CSharpDocumentPropertiesService.Instance);
+                defaultProvider.PromoteBackgroundDocument(@new!.Uri, CSharpDocumentPropertiesService.Instance);
             }
 
             if (kind != LSPDocumentChangeKind.VirtualDocumentChanged)
@@ -64,8 +64,8 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor
 
             if (virtualNew is CSharpVirtualDocumentSnapshot)
             {
-                var csharpContainer = new CSharpVirtualDocumentContainer(_lspDocumentMappingProvider, @new, virtualNew.Snapshot);
-                _dynamicFileInfoProvider.UpdateLSPFileInfo(@new.Uri, csharpContainer);
+                var csharpContainer = new CSharpVirtualDocumentContainer(_lspDocumentMappingProvider, @new!, virtualNew.Snapshot);
+                _dynamicFileInfoProvider.UpdateLSPFileInfo(@new!.Uri, csharpContainer);
             }
         }
 

src/Razor/src/Microsoft.VisualStudio.LanguageServerClient.Razor/CSharpVirtualDocumentSnapshot.cs

@@ -1,8 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System;
 using Microsoft.VisualStudio.LanguageServer.ContainedLanguage;
 using Microsoft.VisualStudio.Text;

src/Razor/src/Microsoft.VisualStudio.LanguageServerClient.Razor/Debugging/CSharpVirtualDocumentDebuggingExtensions.cs

@@ -50,11 +50,8 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.Debugging
                 syntaxTree = await document!.GetSyntaxTreeAsync(cancellationToken).ConfigureAwait(false);
             }
 
-            if (syntaxTree is null)
-            {
-                // Couldn't find the document in the workspace OR the version in the workspace couldn't have its syntax tree computed.
-                syntaxTree = CreateSyntaxTreeFromSnapshot(virtualDocument.Snapshot, cancellationToken);
-            }
+            // Couldn't find the document in the workspace OR the version in the workspace couldn't have its syntax tree computed.
+            syntaxTree ??= CreateSyntaxTreeFromSnapshot(virtualDocument.Snapshot, cancellationToken);
 
             return syntaxTree;
 

src/Razor/src/Microsoft.VisualStudio.LanguageServerClient.Razor/Debugging/RazorBreakpointSpanParams.cs

@@ -1,8 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System;
 using Microsoft.VisualStudio.LanguageServer.Protocol;
 
@@ -10,8 +8,8 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.Debugging
 {
     internal class RazorBreakpointSpanParams
     {
-        public Uri Uri { get; set; }
+        public required Uri Uri { get; init; }
 
-        public Position Position { get; set; }
+        public required Position Position { get; init; }
     }
 }

src/Razor/src/Microsoft.VisualStudio.LanguageServerClient.Razor/Debugging/RazorBreakpointSpanResponse.cs

@@ -1,13 +1,10 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
-
 namespace Microsoft.VisualStudio.LanguageServerClient.Razor.Debugging
 {
     internal class RazorBreakpointSpanResponse
     {
-        public Range Range { get; set; }
+        public required Range Range { get; init; }
     }
 }

src/Razor/src/Microsoft.VisualStudio.LanguageServerClient.Razor/Debugging/RazorProximityExpressionsParams.cs

@@ -1,8 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System;
 using Microsoft.VisualStudio.LanguageServer.Protocol;
 
@@ -10,8 +8,8 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.Debugging
 {
     internal class RazorProximityExpressionsParams
     {
-        public Uri Uri { get; set; }
+        public required Uri Uri { get; init; }
 
-        public Position Position { get; set; }
+        public required Position Position { get; init; }
     }
 }

src/Razor/src/Microsoft.VisualStudio.LanguageServerClient.Razor/Debugging/RazorProximityExpressionsResponse.cs

@@ -1,14 +1,12 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System.Collections.Generic;
 
 namespace Microsoft.VisualStudio.LanguageServerClient.Razor.Debugging
 {
     internal class RazorProximityExpressionsResponse
     {
-        public IReadOnlyList<string> Expressions { get; set; }
+        public required IReadOnlyList<string> Expressions { get; init; }
     }
 }

src/Razor/src/Microsoft.VisualStudio.LanguageServerClient.Razor/DefaultProjectConfigurationFilePathStore.cs

@@ -4,6 +4,7 @@
 using System;
 using System.Collections.Generic;
 using System.Composition;
+using System.Diagnostics.CodeAnalysis;
 using System.IO;
 using Microsoft.CodeAnalysis.Razor;
 using Microsoft.CodeAnalysis.Razor.ProjectSystem;
@@ -79,7 +80,7 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor
             Changed?.Invoke(this, args);
         }
 
-        public override bool TryGet(string projectFilePath, out string configurationFilePath)
+        public override bool TryGet(string projectFilePath, [NotNullWhen(returnValue: true)] out string? configurationFilePath)
         {
             if (projectFilePath is null)
             {

src/Razor/src/Microsoft.VisualStudio.LanguageServerClient.Razor/DefaultRazorLanguageServerCustomMessageTarget.cs

@@ -44,8 +44,6 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor
         private readonly EditorSettingsManager _editorSettingsManager;
         private readonly LSPDocumentSynchronizer _documentSynchronizer;
 
-        private const string RazorReadyFeature = "Razor-Initialization";
-
         [ImportingConstructor]
         public DefaultRazorLanguageServerCustomMessageTarget(
             LSPDocumentManager documentManager,
@@ -130,7 +128,7 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor
             var hostDocumentUri = new Uri(request.HostDocumentFilePath);
             _documentManager.UpdateVirtualDocument<CSharpVirtualDocument>(
                 hostDocumentUri,
-                request.Changes?.Select(change => change.ToVisualStudioTextChange()).ToArray(),
+                request.Changes.Select(change => change.ToVisualStudioTextChange()).ToArray(),
                 request.HostDocumentVersion.Value,
                 state: null);
         }
@@ -158,7 +156,7 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor
             var hostDocumentUri = new Uri(request.HostDocumentFilePath);
             _documentManager.UpdateVirtualDocument<HtmlVirtualDocument>(
                 hostDocumentUri,
-                request.Changes?.Select(change => change.ToVisualStudioTextChange()).ToArray(),
+                request.Changes.Select(change => change.ToVisualStudioTextChange()).ToArray(),
                 request.HostDocumentVersion.Value,
                 state: null);
         }
@@ -873,7 +871,7 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor
             {
                 await _joinableTaskFactory.SwitchToMainThreadAsync(cancellationToken);
 
-                var provisionalChange = new VisualStudioTextChange(request.ProvisionalTextEdit, virtualDocumentSnapshot.Snapshot);
+                var provisionalChange = new VisualStudioTextChange(provisionalTextEdit, virtualDocumentSnapshot.Snapshot);
                 UpdateVirtualDocument(provisionalChange, request.ProjectedKind, request.HostDocument.Version, documentSnapshot.Uri);
 
                 // We want the delegation to continue on the captured context because we're currently on the `main` thread and we need to get back to the
@@ -1065,6 +1063,32 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor
             return response?.Response;
         }
 
+        public override async Task<Range?> ValidateBreakpointRangeAsync(DelegatedValidateBreakpointRangeParams request, CancellationToken cancellationToken)
+        {
+            var delegationDetails = await GetProjectedRequestDetailsAsync(request, cancellationToken).ConfigureAwait(false);
+            if (delegationDetails is null)
+            {
+                return default;
+            }
+
+            var validateBreakpointRangeParams = new VSInternalValidateBreakableRangeParams
+            {
+                TextDocument = new TextDocumentIdentifier()
+                {
+                    Uri = delegationDetails.Value.ProjectedUri,
+                },
+                Range = request.ProjectedRange
+            };
+
+            var response = await _requestInvoker.ReinvokeRequestOnServerAsync<VSInternalValidateBreakableRangeParams, Range?>(
+                delegationDetails.Value.TextBuffer,
+                VSInternalMethods.TextDocumentValidateBreakableRangeName,
+                delegationDetails.Value.LanguageServerName,
+                validateBreakpointRangeParams,
+                cancellationToken).ConfigureAwait(false);
+            return response?.Response;
+        }
+
         public override Task<VSInternalHover?> HoverAsync(DelegatedPositionParams request, CancellationToken cancellationToken)
             => DelegateTextDocumentPositionRequestAsync<VSInternalHover>(request, Methods.TextDocumentHoverName, cancellationToken);
 

src/Razor/src/Microsoft.VisualStudio.LanguageServerClient.Razor/Extensions/ITextSnapshotExtensions.cs

@@ -1,8 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System;
 using System.Diagnostics;
 using Microsoft.VisualStudio.Text;

src/Razor/src/Microsoft.VisualStudio.LanguageServerClient.Razor/Extensions/TextChangeExtensions.cs

@@ -1,8 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System;
 using Microsoft.CodeAnalysis.Text;
 using Microsoft.VisualStudio.LanguageServer.ContainedLanguage;
@@ -14,7 +12,7 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.Extensions
     internal static class TextChangeExtensions
     {
         public static ITextChange ToVisualStudioTextChange(this TextChange roslynTextChange) =>
-            new VisualStudioTextChange(roslynTextChange.Span.Start, roslynTextChange.Span.Length, roslynTextChange.NewText);
+            new VisualStudioTextChange(roslynTextChange.Span.Start, roslynTextChange.Span.Length, roslynTextChange.NewText!);
 
         public static TextEdit AsTextEdit(this TextChange textChange, SourceText sourceText)
         {

src/Razor/src/Microsoft.VisualStudio.LanguageServerClient.Razor/Extensions/TextSpanExtensions.cs

@@ -1,8 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System;
 using Microsoft.AspNetCore.Razor.LanguageServer.Extensions;
 using Microsoft.CodeAnalysis.Text;

src/Razor/src/Microsoft.VisualStudio.LanguageServerClient.Razor/HtmlCSharp/ClassifiedTextElementComparer.cs

@@ -1,8 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System.Collections.Generic;
 using System.Linq;
 using Microsoft.VisualStudio.Text.Adornments;

src/Razor/src/Microsoft.VisualStudio.LanguageServerClient.Razor/HtmlCSharp/CompletionResolveData.cs

@@ -1,17 +1,15 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using Newtonsoft.Json;
 
 namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
 {
     internal class CompletionResolveData
     {
-        public long ResultId { get; set; }
+        public required long ResultId { get; init; }
 
         [JsonProperty(NullValueHandling = NullValueHandling.Ignore)]
-        public object OriginalData { get; set; }
+        public required object OriginalData { get; init; }
     }
 }

src/Razor/src/Microsoft.VisualStudio.LanguageServerClient.Razor/HtmlCSharp/DocumentPullDiagnosticsHandler.cs

@@ -214,7 +214,7 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
                     continue;
                 }
 
-                _logger.LogInformation("Returning {diagnosticsLength} diagnostics.", processedDiagnostics.Diagnostics.Length);
+                _logger.LogInformation("Returning {diagnosticsLength} diagnostics.", processedDiagnostics.Diagnostics?.Length ?? 0);
                 diagnosticReport.Diagnostics = processedDiagnostics.Diagnostics;
 
                 mappedDiagnosticReports.Add(diagnosticReport);

src/Razor/src/Microsoft.VisualStudio.LanguageServerClient.Razor/HtmlCSharp/ExportLspMethodAttribute.cs

@@ -1,8 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System;
 using System.Composition;
 

src/Razor/src/Microsoft.VisualStudio.LanguageServerClient.Razor/HtmlCSharp/FindAllReferencesHandler.cs

@@ -1,8 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System;
 using System.Collections.Generic;
 using System.Composition;
@@ -91,7 +89,7 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
         }
 
         // Internal for testing
-        internal async override Task<VSInternalReferenceItem[]> HandleRequestAsync(ReferenceParams request, ClientCapabilities clientCapabilities, string token, CancellationToken cancellationToken)
+        internal async override Task<VSInternalReferenceItem[]?> HandleRequestAsync(ReferenceParams request, ClientCapabilities clientCapabilities, string token, CancellationToken cancellationToken)
         {
             if (request is null)
             {
@@ -278,7 +276,7 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
             return remappedLocations.ToArray();
         }
 
-        private static object FilterReferenceDisplayText(object referenceText)
+        private static object? FilterReferenceDisplayText(object? referenceText)
         {
             const string CodeBehindObjectPrefix = "__o = ";
             const string CodeBehindBackingFieldSuffix = "k__BackingField";
@@ -330,10 +328,10 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
         private class SerializableReferenceParams : TextDocumentPositionParams
         {
             [DataMember(Name = "context")]
-            public ReferenceContext Context { get; set; }
+            public required ReferenceContext Context { get; init; }
 
             [DataMember(Name = "partialResultToken")]
-            public string PartialResultToken { get; set; }
+            public required string PartialResultToken { get; init; }
         }
     }
 }

src/Razor/src/Microsoft.VisualStudio.LanguageServerClient.Razor/HtmlCSharp/IRequestHandlerMetadata.cs

@@ -1,8 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
 {
     internal interface IRequestHandlerMetadata

src/Razor/src/Microsoft.VisualStudio.LanguageServerClient.Razor/HtmlCSharp/LSPProgressListener.cs

@@ -16,6 +16,6 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
             Func<JToken, CancellationToken, Task> onProgressNotifyAsync,
             Func<CancellationToken, Task> delayAfterLastNotifyAsync,
             CancellationToken handlerCancellationToken,
-            [NotNullWhen(true)] out Task? onCompleted);
+            [NotNullWhen(returnValue: true)] out Task? onCompleted);
     }
 }

src/Razor/src/Microsoft.VisualStudio.LanguageServerClient.Razor/HtmlCSharp/LSPProgressListenerHandlerBase.cs

@@ -1,8 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System;
 using System.Threading;
 using System.Threading.Tasks;
@@ -23,7 +21,7 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
         /// </summary>
         private protected CancellationToken ImmediateNotificationTimeout { get; private set; }
 
-        public async Task<TResult> HandleRequestAsync(TParams requestParams, ClientCapabilities clientCapabilities, CancellationToken cancellationToken)
+        public async Task<TResult?> HandleRequestAsync(TParams requestParams, ClientCapabilities clientCapabilities, CancellationToken cancellationToken)
         {
             // Temporary till IProgress serialization is fixed
             var token = Guid.NewGuid().ToString(); // request.PartialResultToken.Id
@@ -31,7 +29,7 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
         }
 
         // Internal for testing
-        internal abstract Task<TResult> HandleRequestAsync(TParams request, ClientCapabilities clientCapabilities, string token, CancellationToken cancellationToken);
+        internal abstract Task<TResult?> HandleRequestAsync(TParams request, ClientCapabilities clientCapabilities, string token, CancellationToken cancellationToken);
 
         internal TestAccessor GetTestAccessor()
             => new(this);

src/Razor/src/Microsoft.VisualStudio.LanguageServerClient.Razor/HtmlCSharp/LanguageServerKindExtensions.cs

@@ -1,8 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System;
 using Microsoft.VisualStudio.Editor.Razor;
 using Microsoft.VisualStudio.LanguageServer.ContainedLanguage;

src/Razor/src/Microsoft.VisualStudio.LanguageServerClient.Razor/HtmlCSharp/ProjectionResult.cs

@@ -1,8 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
-#nullable disable
-
 using System;
 using Microsoft.AspNetCore.Razor.LanguageServer.Protocol;
 using Microsoft.VisualStudio.LanguageServer.Protocol;
@@ -11,14 +9,14 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
 {
     internal class ProjectionResult
     {
-        public Uri Uri { get; set; }
+        public required Uri Uri { get; init; }
 
-        public Position Position { get; set; }
+        public required Position Position { get; init; }
 
-        public int PositionIndex { get; set; }
+        public int PositionIndex { get; init; }
 
-        public RazorLanguageKind LanguageKind { get; set; }
+        public RazorLanguageKind LanguageKind { get; init; }
 
-        public int? HostDocumentVersion { get; set; }
+        public int? HostDocumentVersion { get; init; }
     }
 }