Fix compilation issues - add missing using statements, fix DocumentUri initialization, add SyntaxNode alias, fix test method calls, extract ShowSerializedTagHelpers_Cohost method

Co-authored-by: davidwengier <754264+davidwengier@users.noreply.github.com>

Author: Copilot

src/Razor/src/Microsoft.CodeAnalysis.Razor.CohostingShared/DevTools/CohostGeneratedDocumentContentsEndpoint.cs

@@ -7,6 +7,7 @@
 using System.Threading.Tasks;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.ExternalAccess.Razor.Cohost;
+using Microsoft.CodeAnalysis.ExternalAccess.Razor.Features;
 using Microsoft.CodeAnalysis.Razor.Cohost;
 using Microsoft.CodeAnalysis.Razor.Protocol.DevTools;
 using Microsoft.CodeAnalysis.Razor.Remote;

src/Razor/src/Microsoft.CodeAnalysis.Razor.CohostingShared/DevTools/CohostSyntaxTreeEndpoint.cs

@@ -6,6 +6,7 @@
 using System.Threading.Tasks;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.ExternalAccess.Razor.Cohost;
+using Microsoft.CodeAnalysis.ExternalAccess.Razor.Features;
 using Microsoft.CodeAnalysis.Razor.Cohost;
 using Microsoft.CodeAnalysis.Razor.Protocol.DevTools;
 using Microsoft.CodeAnalysis.Razor.Remote;

src/Razor/src/Microsoft.CodeAnalysis.Razor.CohostingShared/DevTools/CohostTagHelpersEndpoint.cs

@@ -9,6 +9,7 @@
 using Microsoft.AspNetCore.Razor.Language;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.ExternalAccess.Razor.Cohost;
+using Microsoft.CodeAnalysis.ExternalAccess.Razor.Features;
 using Microsoft.CodeAnalysis.Razor.Cohost;
 using Microsoft.CodeAnalysis.Razor.Protocol.DevTools;
 using Microsoft.CodeAnalysis.Razor.Remote;

src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/Protocol/DevTools/DocumentContentsRequest.cs

@@ -18,7 +18,7 @@ public static DocumentContentsRequest Create(Uri hostDocumentUri, GeneratedDocum
     {
         return new DocumentContentsRequest
         {
-            TextDocument = new TextDocumentIdentifier { DocumentUri = hostDocumentUri },
+            TextDocument = new TextDocumentIdentifier { DocumentUri = new(hostDocumentUri) },
             Kind = kind
         };
     }

src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/DevTools/RemoteDevToolsService.cs

@@ -16,6 +16,8 @@
 
 namespace Microsoft.CodeAnalysis.Remote.Razor;
 
+using SyntaxNode = Microsoft.AspNetCore.Razor.Language.Syntax.SyntaxNode;
+
 internal sealed class RemoteDevToolsService(in ServiceArgs args) : RazorDocumentServiceBase(in args), IRemoteDevToolsService
 {
     internal sealed class Factory : FactoryBase<IRemoteDevToolsService>

src/Razor/src/Microsoft.VisualStudio.RazorExtension/SyntaxVisualizer/SyntaxVisualizerControl.xaml.cs

@@ -241,6 +241,50 @@ private bool ShowGeneratedCode_Cohost(ITextBuffer textBuffer, Uri hostDocumentUr
         return false;
     }
 
+    private bool ShowSerializedTagHelpers_Cohost(ITextBuffer textBuffer, Uri hostDocumentUri, TagHelperDisplayMode displayKind)
+    {
+        EnsureInitialized();
+
+        var tagHelpersKind = displayKind switch
+        {
+            TagHelperDisplayMode.All => TagHelpersKind.All,
+            TagHelperDisplayMode.InScope => TagHelpersKind.InScope,
+            TagHelperDisplayMode.Referenced => TagHelpersKind.Referenced,
+            _ => TagHelpersKind.All
+        };
+
+        var request = TagHelpersRequest.Create(hostDocumentUri, tagHelpersKind);
+
+        var response = _joinableTaskFactory.Run(async () =>
+        {
+            var lspResponse = await _lspRequestInvoker.ReinvokeRequestOnServerAsync<TagHelpersRequest, string>(
+                textBuffer,
+                "razor/tagHelpers",
+                RazorLSPConstants.RoslynLanguageServerName,
+                request,
+                CancellationToken.None);
+
+            return lspResponse?.Response;
+        });
+
+        if (response != null)
+        {
+            var tempFileName = GetTempFileName(displayKind.ToString() + "TagHelpers.json");
+            try
+            {
+                File.WriteAllText(tempFileName, response);
+                VsShellUtilities.OpenDocument(ServiceProvider.GlobalProvider, tempFileName);
+                return true;
+            }
+            catch
+            {
+                // Fall through to legacy method
+            }
+        }
+
+        return false;
+    }
+
     public void ShowSerializedTagHelpers(TagHelperDisplayMode displayKind)
     {
         ThreadHelper.ThrowIfNotOnUIThread();
@@ -251,41 +295,9 @@ public void ShowSerializedTagHelpers(TagHelperDisplayMode displayKind)
         {
             if (_fileUriProvider.TryGet(_activeWpfTextView.TextBuffer, out var hostDocumentUri))
             {
-                var tagHelpersKind = displayKind switch
+                if (ShowSerializedTagHelpers_Cohost(_activeWpfTextView.TextBuffer, hostDocumentUri, displayKind))
                 {
-                    TagHelperDisplayMode.All => TagHelpersKind.All,
-                    TagHelperDisplayMode.InScope => TagHelpersKind.InScope,
-                    TagHelperDisplayMode.Referenced => TagHelpersKind.Referenced,
-                    _ => TagHelpersKind.All
-                };
-
-                var request = TagHelpersRequest.Create(hostDocumentUri, tagHelpersKind);
-
-                var response = _joinableTaskFactory.Run(async () =>
-                {
-                    var lspResponse = await _lspRequestInvoker.ReinvokeRequestOnServerAsync<TagHelpersRequest, string>(
-                        _activeWpfTextView.TextBuffer,
-                        "razor/tagHelpers",
-                        RazorLSPConstants.RoslynLanguageServerName,
-                        request,
-                        CancellationToken.None);
-
-                    return lspResponse?.Response;
-                });
-
-                if (response != null)
-                {
-                    var tempFileName = GetTempFileName(displayKind.ToString() + "TagHelpers.json");
-                    try
-                    {
-                        File.WriteAllText(tempFileName, response);
-                        VsShellUtilities.OpenDocument(ServiceProvider.GlobalProvider, tempFileName);
-                        return;
-                    }
-                    catch
-                    {
-                        // Fall through to legacy method
-                    }
+                    return;
                 }
             }
         }

src/Razor/test/Microsoft.VisualStudio.LanguageServices.Razor.Test/Cohost/Shared/CohostDevToolsEndpointTest.cs

@@ -4,6 +4,7 @@
 using System.Text.Json;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Razor;
+using Microsoft.CodeAnalysis.ExternalAccess.Razor;
 using Microsoft.CodeAnalysis.Razor.Protocol.DevTools;
 using Microsoft.CodeAnalysis.Testing;
 using Roslyn.LanguageServer.Protocol;
@@ -61,7 +62,7 @@ public async Task GetTagHelpers_ReturnsJson()
                 <div>Test content</div>
                 """;
 
-        var razorDocument = await CreateDocumentAsync(input);
+        var razorDocument = CreateProjectAndRazorDocument(input);
         var endpoint = new CohostTagHelpersEndpoint(IncompatibleProjectService, RemoteServiceInvoker);
 
         var request = new TagHelpersRequest
@@ -90,7 +91,7 @@ public async Task GetSyntaxTree_ReturnsTree()
                 <div>@message</div>
                 """;
 
-        var razorDocument = await CreateDocumentAsync(input);
+        var razorDocument = CreateProjectAndRazorDocument(input);
         var endpoint = new CohostSyntaxTreeEndpoint(IncompatibleProjectService, RemoteServiceInvoker);
 
         var request = new SyntaxTreeRequest
@@ -109,7 +110,7 @@ public async Task GetSyntaxTree_ReturnsTree()
 
     private async Task VerifyGeneratedDocumentContentsAsync(string input, GeneratedDocumentKind kind, string expectedContentSubstring, string expectedFileExtension)
     {
-        var razorDocument = await CreateDocumentAsync(input);
+        var razorDocument = CreateProjectAndRazorDocument(input);
         var endpoint = new CohostGeneratedDocumentContentsEndpoint(IncompatibleProjectService, RemoteServiceInvoker);
 
         var request = new DocumentContentsRequest