Razor EA changes to better support the dataTipRange LSP message in cohosting

The razor side will come after this change is published and consumable by razor.

Author: ToddGrun

src/LanguageServer/Protocol/Handler/DataTips/DataTipRangeHandler.cs

@@ -9,6 +9,7 @@
 using Microsoft.CodeAnalysis.Debugging;
 using Microsoft.CodeAnalysis.Host.Mef;
 using Microsoft.CodeAnalysis.Shared.Extensions;
+using Microsoft.CodeAnalysis.Text;
 using Roslyn.LanguageServer.Protocol;
 
 namespace Microsoft.CodeAnalysis.LanguageServer.Handler;
@@ -26,14 +27,14 @@ internal sealed class DataTipRangeHandler()
     public TextDocumentIdentifier GetTextDocumentIdentifier(TextDocumentPositionParams request)
         => request.TextDocument;
 
-    public async Task<VSInternalDataTip?> HandleRequestAsync(TextDocumentPositionParams request, RequestContext context, CancellationToken cancellationToken)
-    {
-        var document = context.GetRequiredDocument();
+    public Task<VSInternalDataTip?> HandleRequestAsync(TextDocumentPositionParams request, RequestContext context, CancellationToken cancellationToken)
+        => GetDataTipRangeAsync(context.GetRequiredDocument(), ProtocolConversions.PositionToLinePosition(request.Position), cancellationToken);
 
+    public static async Task<VSInternalDataTip?> GetDataTipRangeAsync(Document document, LinePosition linePosition, CancellationToken cancellationToken)
+    {
         var service = document.GetRequiredLanguageService<ILanguageDebugInfoService>();
 
         var text = await document.GetValueTextAsync(cancellationToken).ConfigureAwait(false);
-        var linePosition = ProtocolConversions.PositionToLinePosition(request.Position);
         var position = text.Lines.GetPosition(linePosition);
         var info = await service.GetDataTipInfoAsync(document, position, includeKind: true, cancellationToken).ConfigureAwait(false);
         if (info.IsDefault)

src/Tools/ExternalAccess/Razor/Features/Cohost/Handlers/DataTipRange.cs

@@ -0,0 +1,19 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.CodeAnalysis.LanguageServer.Handler;
+using Microsoft.CodeAnalysis.Text;
+using Roslyn.LanguageServer.Protocol;
+
+namespace Microsoft.CodeAnalysis.ExternalAccess.Razor.Cohost.Handlers;
+
+internal static class DataTipRange
+{
+    public static async Task<VSInternalDataTip?> GetDataTipRangeAsync(Document document, LinePosition linePosition, CancellationToken cancellationToken)
+    {
+        return await DataTipRangeHandler.GetDataTipRangeAsync(document, linePosition, cancellationToken).ConfigureAwait(false);
+    }
+}