Migrate HTMLC# `textDocument/completion` to new delegation APIs

- Added a `ReinvocationResponse` extension to extract results or log to make reinvocation responses easier to handle.
- Updated the tests to reflect the new dependency on document snapshots and their virtual documents.

Part of #5017

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

@@ -12,6 +12,7 @@ using Microsoft.VisualStudio.LanguageServer.ContainedLanguage;
 using Microsoft.VisualStudio.LanguageServer.Protocol;
 using Microsoft.VisualStudio.LanguageServerClient.Razor.Extensions;
 using Microsoft.VisualStudio.LanguageServerClient.Razor.Logging;
+using Microsoft.VisualStudio.Text;
 using Microsoft.VisualStudio.Text.Operations;
 using Microsoft.VisualStudio.Threading;
 
@@ -212,12 +213,18 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
 
                 _logger.LogInformation($"Requesting non-provisional completions for {projectedDocumentUri}.");
 
+                var textBuffer = serverKind.GetTextBuffer(documentSnapshot);
                 var response = await _requestInvoker.ReinvokeRequestOnServerAsync<CompletionParams, SumType<CompletionItem[], CompletionList>?>(
+                    textBuffer,
                     Methods.TextDocumentCompletionName,
                     languageServerName,
                     completionParams,
                     cancellationToken).ConfigureAwait(false);
-                result = response.Result;
+
+                if (!response.TryExtractResultOrLog(_logger, languageServerName, out result))
+                {
+                    return null;
+                }
 
                 _logger.LogInformation("Found non-provisional completion");
             }
@@ -652,12 +659,18 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
 
             _logger.LogInformation($"Requesting provisional completion for {previousCharacterProjection.Uri}.");
 
+            var textBuffer = LanguageServerKind.CSharp.GetTextBuffer(documentSnapshot);
             var response = await _requestInvoker.ReinvokeRequestOnServerAsync<CompletionParams, SumType<CompletionItem[], CompletionList>?>(
+                textBuffer,
                 Methods.TextDocumentCompletionName,
                 RazorLSPConstants.RazorCSharpLanguageServerName,
                 provisionalCompletionParams,
                 cancellationToken).ConfigureAwait(true);
-            result = response.Result;
+
+            if (!response.TryExtractResultOrLog(_logger, RazorLSPConstants.RazorCSharpLanguageServerName, out result))
+            {
+                return (false, result);
+            }
 
             // We have now obtained the necessary completion items. We no longer need the provisional change. Revert.
             var removeProvisionalDot = new VisualStudioTextChange(previousCharacterProjection.PositionIndex, 1, string.Empty);

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

@@ -0,0 +1,38 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the MIT license. See License.txt in the project root for license information.
+
+using System.Diagnostics.CodeAnalysis;
+using Microsoft.Extensions.Logging;
+using Microsoft.VisualStudio.LanguageServer.ContainedLanguage;
+
+#nullable enable
+
+namespace Microsoft.VisualStudio.LanguageServerClient.Razor
+{
+    internal static class ReinvocationResponseExtensions
+    {
+        public static bool TryExtractResultOrLog<TResponseType>(
+            this ReinvocationResponse<TResponseType> response,
+            ILogger logger,
+            string fromLanguageServerName,
+            [NotNullWhen(true)] out TResponseType? result)
+        {
+            if (response is null)
+            {
+                logger.LogInformation("Could not make a request against language server {0}.", fromLanguageServerName);
+                result = default;
+                return false;
+            }
+
+            if (response.Response is null)
+            {
+                logger.LogInformation("Language server {0} returned a `null` result.", fromLanguageServerName);
+                result = default;
+                return false;
+            }
+
+            result = response.Response;
+            return true;
+        }
+    }
+}

src/Razor/test/Microsoft.VisualStudio.LanguageServerClient.Razor.Test/HtmlCSharp/CompletionHandlerTest.cs

@@ -9,6 +9,7 @@ using Microsoft.AspNetCore.Razor.Test.Common;
 using Microsoft.VisualStudio.LanguageServer.Client;
 using Microsoft.VisualStudio.LanguageServer.ContainedLanguage;
 using Microsoft.VisualStudio.LanguageServer.Protocol;
+using Microsoft.VisualStudio.Test;
 using Microsoft.VisualStudio.Text;
 using Microsoft.VisualStudio.Text.Operations;
 using Microsoft.VisualStudio.Threading;
@@ -32,6 +33,10 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
 
             CompletionRequestContextCache = new CompletionRequestContextCache();
             FormattingOptionsProvider = TestFormattingOptionsProvider.Default;
+
+            TextBuffer = new TestTextBuffer(new StringTextSnapshot(string.Empty));
+            CSharpVirtualDocumentSnapshot = new CSharpVirtualDocumentSnapshot(new Uri("C:/path/to/file.razor.g.cs"), TextBuffer.CurrentSnapshot, 0);
+            HtmlVirtualDocumentSnapshot = new HtmlVirtualDocumentSnapshot(new Uri("C:/path/to/file.razor__virtual.html"), TextBuffer.CurrentSnapshot, 0);
         }
 
         private JoinableTaskContext JoinableTaskContext { get; }
@@ -42,9 +47,15 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
 
         private FormattingOptionsProvider FormattingOptionsProvider { get; }
 
+        private TestTextBuffer TextBuffer { get; }
+
+        private CSharpVirtualDocumentSnapshot CSharpVirtualDocumentSnapshot { get; }
+
+        private HtmlVirtualDocumentSnapshot HtmlVirtualDocumentSnapshot { get; }
+
         private Uri Uri { get; }
 
-        private readonly ILanguageClient _languageClient = Mock.Of<ILanguageClient>(MockBehavior.Strict);
+        private readonly string _languageClient = "languageClient";
 
         [Theory]
         [WorkItem("https://github.com/dotnet/razor-tooling/issues/5606")]
@@ -161,7 +172,7 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
         {
             // Arrange
             var documentManager = new TestDocumentManager();
-            documentManager.AddDocument(Uri, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0));
+            documentManager.AddDocument(Uri, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0, CSharpVirtualDocumentSnapshot));
             var requestInvoker = Mock.Of<LSPRequestInvoker>(MockBehavior.Strict);
             var projectionProvider = new Mock<LSPProjectionProvider>(MockBehavior.Strict).Object;
             Mock.Get(projectionProvider).Setup(projectionProvider => projectionProvider.GetProjectionAsync(It.IsAny<LSPDocumentSnapshot>(), It.IsAny<Position>(), CancellationToken.None))
@@ -237,12 +248,12 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
             };
 
             var documentManager = new TestDocumentManager();
-            documentManager.AddDocument(Uri, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0));
+            documentManager.AddDocument(Uri, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0, HtmlVirtualDocumentSnapshot));
 
             var requestInvoker = new Mock<LSPRequestInvoker>(MockBehavior.Strict);
             requestInvoker
-                .Setup(r => r.ReinvokeRequestOnServerAsync<CompletionParams, SumType<CompletionItem[], CompletionList>?>(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CompletionParams>(), It.IsAny<CancellationToken>()))
-                .Callback<string, string, CompletionParams, CancellationToken>((method, clientName, completionParams, ct) =>
+                .Setup(r => r.ReinvokeRequestOnServerAsync<CompletionParams, SumType<CompletionItem[], CompletionList>?>(TextBuffer, It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CompletionParams>(), It.IsAny<CancellationToken>()))
+                .Callback<ITextBuffer, string, string, CompletionParams, CancellationToken>((textBuffer, method, clientName, completionParams, ct) =>
                 {
                     Assert.Equal(Methods.TextDocumentCompletionName, method);
                     Assert.Equal(RazorLSPConstants.HtmlLanguageServerName, clientName);
@@ -250,7 +261,7 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
                     Assert.Equal(VSInternalCompletionInvokeKind.Typing, vsCompletionContext.InvokeKind);
                     called = true;
                 })
-                .Returns(Task.FromResult(new ReinvokeResponse<SumType<CompletionItem[], CompletionList>?>(_languageClient, new[] { expectedItem })));
+                .Returns(Task.FromResult(new ReinvocationResponse<SumType<CompletionItem[], CompletionList>?>(_languageClient, new[] { expectedItem })));
 
             var projectionResult = new ProjectionResult()
             {
@@ -287,19 +298,24 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
             };
 
             var documentManager = new TestDocumentManager();
-            documentManager.AddDocument(Uri, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0));
+            documentManager.AddDocument(Uri, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0, HtmlVirtualDocumentSnapshot, CSharpVirtualDocumentSnapshot));
 
             var requestInvoker = new Mock<LSPRequestInvoker>(MockBehavior.Strict);
             requestInvoker
-                .Setup(r => r.ReinvokeRequestOnServerAsync<CompletionParams, SumType<CompletionItem[], CompletionList>?>(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CompletionParams>(), It.IsAny<CancellationToken>()))
-                .Callback<string, string, CompletionParams, CancellationToken>((method, clientName, completionParams, ct) =>
+                .Setup(r => r.ReinvokeRequestOnServerAsync<CompletionParams, SumType<CompletionItem[], CompletionList>?>(
+                    It.IsAny<ITextBuffer>(),
+                    It.IsAny<string>(),
+                    It.IsAny<string>(),
+                    It.IsAny<CompletionParams>(),
+                    It.IsAny<CancellationToken>()))
+                .Callback<ITextBuffer, string, string, CompletionParams, CancellationToken>((textBuffer, method, clientName, completionParams, ct) =>
                 {
                     Assert.Equal(Methods.TextDocumentCompletionName, method);
                     var vsCompletionContext = Assert.IsType<VSInternalCompletionContext>(completionParams.Context);
                     Assert.Equal(VSInternalCompletionInvokeKind.Explicit, vsCompletionContext.InvokeKind);
                     called = true;
                 })
-                .Returns(Task.FromResult(new ReinvokeResponse<SumType<CompletionItem[], CompletionList>?>(_languageClient, new[] { expectedItem })));
+                .Returns(Task.FromResult(new ReinvocationResponse<SumType<CompletionItem[], CompletionList>?>(_languageClient, new[] { expectedItem })));
 
             var projectionResult = new ProjectionResult()
             {
@@ -331,12 +347,12 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
             };
 
             var documentManager = new TestDocumentManager();
-            documentManager.AddDocument(Uri, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0));
+            documentManager.AddDocument(Uri, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0, HtmlVirtualDocumentSnapshot));
 
             var requestInvoker = new Mock<LSPRequestInvoker>(MockBehavior.Strict);
             requestInvoker
-                .Setup(r => r.ReinvokeRequestOnServerAsync<CompletionParams, SumType<CompletionItem[], CompletionList>?>(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CompletionParams>(), It.IsAny<CancellationToken>()))
-                .Returns(Task.FromResult(new ReinvokeResponse<SumType<CompletionItem[], CompletionList>?>(null, null)))
+                .Setup(r => r.ReinvokeRequestOnServerAsync<CompletionParams, SumType<CompletionItem[], CompletionList>?>(TextBuffer, It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CompletionParams>(), It.IsAny<CancellationToken>()))
+                .Returns(Task.FromResult(new ReinvocationResponse<SumType<CompletionItem[], CompletionList>?>(String.Empty, null)))
                 .Verifiable();
 
             var projectionResult = new ProjectionResult()
@@ -370,12 +386,12 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
             };
 
             var documentManager = new TestDocumentManager();
-            documentManager.AddDocument(Uri, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0));
+            documentManager.AddDocument(Uri, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0, CSharpVirtualDocumentSnapshot));
 
             var requestInvoker = new Mock<LSPRequestInvoker>(MockBehavior.Strict);
             requestInvoker
-                .Setup(r => r.ReinvokeRequestOnServerAsync<CompletionParams, SumType<CompletionItem[], CompletionList>?>(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CompletionParams>(), It.IsAny<CancellationToken>()))
-                .Callback<string, string, CompletionParams, CancellationToken>((method, clientName, completionParams, ct) =>
+                .Setup(r => r.ReinvokeRequestOnServerAsync<CompletionParams, SumType<CompletionItem[], CompletionList>?>(TextBuffer, It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CompletionParams>(), It.IsAny<CancellationToken>()))
+                .Callback<ITextBuffer, string, string, CompletionParams, CancellationToken>((textBuffer, method, clientName, completionParams, ct) =>
                 {
                     Assert.Equal(Methods.TextDocumentCompletionName, method);
                     Assert.Equal(RazorLSPConstants.RazorCSharpLanguageServerName, clientName);
@@ -383,7 +399,7 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
                     Assert.Equal(VSInternalCompletionInvokeKind.Explicit, vsCompletionContext.InvokeKind);
                     called = true;
                 })
-                .Returns(Task.FromResult(new ReinvokeResponse<SumType<CompletionItem[], CompletionList>?>(_languageClient, new[] { expectedItem })));
+                .Returns(Task.FromResult(new ReinvocationResponse<SumType<CompletionItem[], CompletionList>?>(_languageClient, new[] { expectedItem })));
 
             var projectionResult = new ProjectionResult()
             {
@@ -417,18 +433,19 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
             };
 
             var documentManager = new TestDocumentManager();
-            documentManager.AddDocument(Uri, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0));
+            documentManager.AddDocument(Uri, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0, CSharpVirtualDocumentSnapshot));
 
             var requestInvoker = new Mock<LSPRequestInvoker>(MockBehavior.Strict);
             requestInvoker
                 .Setup(r => r.ReinvokeRequestOnServerAsync<CompletionParams, SumType<CompletionItem[], CompletionList>?>(
+                    TextBuffer,
                     Methods.TextDocumentCompletionName,
                     RazorLSPConstants.RazorCSharpLanguageServerName,
                     It.IsAny<CompletionParams>(),
                     It.IsAny<CancellationToken>()))
-                .Callback<string, string, CompletionParams, CancellationToken>((method, _, completionParams, ct) => called = true)
+                .Callback<ITextBuffer, string, string, CompletionParams, CancellationToken>((textBuffer, method, _, completionParams, ct) => called = true)
                 .Returns(Task.FromResult(
-                    new ReinvokeResponse<SumType<CompletionItem[], CompletionList>?>(
+                    new ReinvocationResponse<SumType<CompletionItem[], CompletionList>?>(
                         _languageClient,
                     new CompletionList
                     {
@@ -499,17 +516,18 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
             };
 
             var documentManager = new TestDocumentManager();
-            documentManager.AddDocument(Uri, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0));
+            documentManager.AddDocument(Uri, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0, CSharpVirtualDocumentSnapshot));
 
             var requestInvoker = new Mock<LSPRequestInvoker>(MockBehavior.Strict);
             requestInvoker
                 .Setup(r => r.ReinvokeRequestOnServerAsync<CompletionParams, SumType<CompletionItem[], CompletionList>?>(
+                    TextBuffer,
                     Methods.TextDocumentCompletionName,
                     RazorLSPConstants.RazorCSharpLanguageServerName,
                     It.IsAny<CompletionParams>(),
                     It.IsAny<CancellationToken>()))
-                .Callback<string, string, CompletionParams, CancellationToken>((method, clientName, completionParams, ct) => called = true)
-                .Returns(Task.FromResult(new ReinvokeResponse<SumType<CompletionItem[], CompletionList>?>(_languageClient, new CompletionList
+                .Callback<ITextBuffer, string, string, CompletionParams, CancellationToken>((textBuffer, method, clientName, completionParams, ct) => called = true)
+                .Returns(Task.FromResult(new ReinvocationResponse<SumType<CompletionItem[], CompletionList>?>(_languageClient, new CompletionList
                 {
                     Items = new[] { expectedItem }
                 })));
@@ -555,18 +573,18 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
             };
 
             var documentManager = new TestDocumentManager();
-            documentManager.AddDocument(Uri, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0));
+            documentManager.AddDocument(Uri, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0, CSharpVirtualDocumentSnapshot));
 
             var requestInvoker = new Mock<LSPRequestInvoker>(MockBehavior.Strict);
             requestInvoker
-                .Setup(r => r.ReinvokeRequestOnServerAsync<CompletionParams, SumType<CompletionItem[], CompletionList>?>(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CompletionParams>(), It.IsAny<CancellationToken>()))
-                .Callback<string, string, CompletionParams, CancellationToken>((method, clientName, completionParams, ct) =>
+                .Setup(r => r.ReinvokeRequestOnServerAsync<CompletionParams, SumType<CompletionItem[], CompletionList>?>(TextBuffer, It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CompletionParams>(), It.IsAny<CancellationToken>()))
+                .Callback<ITextBuffer, string, string, CompletionParams, CancellationToken>((textBuffer, method, clientName, completionParams, ct) =>
                 {
                     Assert.Equal(Methods.TextDocumentCompletionName, method);
                     Assert.Equal(RazorLSPConstants.RazorCSharpLanguageServerName, clientName);
                     called = true;
                 })
-                .Returns(Task.FromResult(new ReinvokeResponse<SumType<CompletionItem[], CompletionList>?>(_languageClient, new CompletionList
+                .Returns(Task.FromResult(new ReinvocationResponse<SumType<CompletionItem[], CompletionList>?>(_languageClient, new CompletionList
                 {
                     Items = new[] { expectedItem }
                 })));
@@ -617,18 +635,18 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
             };
 
             var documentManager = new TestDocumentManager();
-            documentManager.AddDocument(Uri, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0));
+            documentManager.AddDocument(Uri, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0, CSharpVirtualDocumentSnapshot));
 
             var requestInvoker = new Mock<LSPRequestInvoker>(MockBehavior.Strict);
             requestInvoker
-                .Setup(r => r.ReinvokeRequestOnServerAsync<CompletionParams, SumType<CompletionItem[], CompletionList>?>(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CompletionParams>(), It.IsAny<CancellationToken>()))
-                .Callback<string, string, CompletionParams, CancellationToken>((method, clientName, completionParams, ct) =>
+                .Setup(r => r.ReinvokeRequestOnServerAsync<CompletionParams, SumType<CompletionItem[], CompletionList>?>(TextBuffer, It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CompletionParams>(), It.IsAny<CancellationToken>()))
+                .Callback<ITextBuffer, string, string, CompletionParams, CancellationToken>((textBuffer, method, clientName, completionParams, ct) =>
                 {
                     Assert.Equal(Methods.TextDocumentCompletionName, method);
                     Assert.Equal(RazorLSPConstants.RazorCSharpLanguageServerName, clientName);
                     called = true;
                 })
-                .Returns(Task.FromResult(new ReinvokeResponse<SumType<CompletionItem[], CompletionList>?>(_languageClient, expectedItems)));
+                .Returns(Task.FromResult(new ReinvocationResponse<SumType<CompletionItem[], CompletionList>?>(_languageClient, expectedItems)));
 
             var projectionResult = new ProjectionResult()
             {
@@ -692,7 +710,7 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
                 Position = new Position(0, 1)
             };
 
-            var documentSnapshot = new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0, snapshotContent: "@Da");
+            var documentSnapshot = new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0, snapshotContent: "@Da", CSharpVirtualDocumentSnapshot);
             var documentManager = new TestDocumentManager();
             documentManager.AddDocument(Uri, documentSnapshot);
 
@@ -701,14 +719,14 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
             var navigatorSelector = BuildNavigatorSelector(wordRange);
             var requestInvoker = new Mock<LSPRequestInvoker>(MockBehavior.Strict);
             requestInvoker
-                .Setup(r => r.ReinvokeRequestOnServerAsync<CompletionParams, SumType<CompletionItem[], CompletionList>?>(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CompletionParams>(), It.IsAny<CancellationToken>()))
-                .Callback<string, string, CompletionParams, CancellationToken>((method, clientName, completionParams, ct) =>
+                .Setup(r => r.ReinvokeRequestOnServerAsync<CompletionParams, SumType<CompletionItem[], CompletionList>?>(TextBuffer, It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CompletionParams>(), It.IsAny<CancellationToken>()))
+                .Callback<ITextBuffer, string, string, CompletionParams, CancellationToken>((textBuffer, method, clientName, completionParams, ct) =>
                 {
                     Assert.Equal(Methods.TextDocumentCompletionName, method);
                     Assert.Equal(RazorLSPConstants.RazorCSharpLanguageServerName, clientName);
                     called = true;
                 })
-                .Returns(Task.FromResult(new ReinvokeResponse<SumType<CompletionItem[], CompletionList>?>(_languageClient, expectedItems)));
+                .Returns(Task.FromResult(new ReinvocationResponse<SumType<CompletionItem[], CompletionList>?>(_languageClient, expectedItems)));
 
             var projectionResult = new ProjectionResult()
             {
@@ -768,7 +786,7 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
                 Position = new Position(0, 3)
             };
 
-            var documentSnapshot = new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0, snapshotContent: "@us");
+            var documentSnapshot = new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0, snapshotContent: "@us", CSharpVirtualDocumentSnapshot);
             var documentManager = new TestDocumentManager();
             documentManager.AddDocument(Uri, documentSnapshot);
 
@@ -777,14 +795,14 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
             var navigatorSelector = BuildNavigatorSelector(wordRange);
             var requestInvoker = new Mock<LSPRequestInvoker>(MockBehavior.Strict);
             requestInvoker
-                .Setup(r => r.ReinvokeRequestOnServerAsync<CompletionParams, SumType<CompletionItem[], CompletionList>?>(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CompletionParams>(), It.IsAny<CancellationToken>()))
-                .Callback<string, string, CompletionParams, CancellationToken>((method, clientName, completionParams, ct) =>
+                .Setup(r => r.ReinvokeRequestOnServerAsync<CompletionParams, SumType<CompletionItem[], CompletionList>?>(TextBuffer, It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CompletionParams>(), It.IsAny<CancellationToken>()))
+                .Callback<ITextBuffer, string, string, CompletionParams, CancellationToken>((textBuffer, method, clientName, completionParams, ct) =>
                 {
                     Assert.Equal(Methods.TextDocumentCompletionName, method);
                     Assert.Equal(RazorLSPConstants.RazorCSharpLanguageServerName, clientName);
                     called = true;
                 })
-                .Returns(Task.FromResult(new ReinvokeResponse<SumType<CompletionItem[], CompletionList>?>(_languageClient, Array.Empty<CompletionItem>())));
+                .Returns(Task.FromResult(new ReinvocationResponse<SumType<CompletionItem[], CompletionList>?>(_languageClient, Array.Empty<CompletionItem>())));
 
             var projectionResult = new ProjectionResult()
             {
@@ -838,7 +856,7 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
             };
 
             var documentManager = new TestDocumentManager();
-            documentManager.AddDocument(Uri, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0));
+            documentManager.AddDocument(Uri, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0, CSharpVirtualDocumentSnapshot));
 
             var requestInvoker = new Mock<LSPRequestInvoker>(MockBehavior.Strict);
 
@@ -870,7 +888,7 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
             };
 
             var documentManager = new TestDocumentManager();
-            documentManager.AddDocument(Uri, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0));
+            documentManager.AddDocument(Uri, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0, CSharpVirtualDocumentSnapshot));
 
             var requestInvoker = new Mock<LSPRequestInvoker>(MockBehavior.Strict);
 
@@ -904,17 +922,18 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
             };
 
             var documentManager = new TestDocumentManager();
-            documentManager.AddDocument(Uri, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0));
+            documentManager.AddDocument(Uri, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0, CSharpVirtualDocumentSnapshot));
 
             var requestInvoker = new Mock<LSPRequestInvoker>(MockBehavior.Strict);
             requestInvoker
                 .Setup(r => r.ReinvokeRequestOnServerAsync<CompletionParams, SumType<CompletionItem[], CompletionList>?>(
+                    TextBuffer,
                     Methods.TextDocumentCompletionName,
                     RazorLSPConstants.RazorCSharpLanguageServerName,
                     It.IsAny<CompletionParams>(),
                     It.IsAny<CancellationToken>()))
-                .Callback<string, string, CompletionParams, CancellationToken>((method, clientName, completionParams, ct) => called = true)
-                .Returns(Task.FromResult(new ReinvokeResponse<SumType<CompletionItem[], CompletionList>?>(_languageClient, new[] { expectedItem })));
+                .Callback<ITextBuffer, string, string, CompletionParams, CancellationToken>((textBuffer, method, clientName, completionParams, ct) => called = true)
+                .Returns(Task.FromResult(new ReinvocationResponse<SumType<CompletionItem[], CompletionList>?>(_languageClient, new[] { expectedItem })));
 
             var projectionResult = new ProjectionResult()
             {
@@ -949,19 +968,19 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
             };
 
             var documentManager = new TestDocumentManager();
-            documentManager.AddDocument(Uri, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0));
+            documentManager.AddDocument(Uri, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0, CSharpVirtualDocumentSnapshot));
 
             var requestInvoker = new Mock<LSPRequestInvoker>(MockBehavior.Strict);
             requestInvoker
-                .Setup(r => r.ReinvokeRequestOnServerAsync<CompletionParams, SumType<CompletionItem[], CompletionList>?>(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CompletionParams>(), It.IsAny<CancellationToken>()))
-                .Callback<string, string, CompletionParams, CancellationToken>((method, clientName, completionParams, ct) =>
+                .Setup(r => r.ReinvokeRequestOnServerAsync<CompletionParams, SumType<CompletionItem[], CompletionList>?>(TextBuffer, It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CompletionParams>(), It.IsAny<CancellationToken>()))
+                .Callback<ITextBuffer, string, string, CompletionParams, CancellationToken>((textBuffer, method, clientName, completionParams, ct) =>
                 {
                     Assert.Equal(Methods.TextDocumentCompletionName, method);
                     Assert.Equal(RazorLSPConstants.RazorCSharpLanguageServerName, clientName);
                     Assert.Equal(CompletionTriggerKind.Invoked, completionParams.Context.TriggerKind);
                     called = true;
                 })
-                .Returns(Task.FromResult(new ReinvokeResponse<SumType<CompletionItem[], CompletionList>?>(_languageClient, new[] { expectedItem })));
+                .Returns(Task.FromResult(new ReinvocationResponse<SumType<CompletionItem[], CompletionList>?>(_languageClient, new[] { expectedItem })));
 
             var projectionResult = new ProjectionResult()
             {
@@ -1004,18 +1023,18 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
             };
 
             var documentManager = new TestDocumentManager();
-            documentManager.AddDocument(Uri, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0));
+            documentManager.AddDocument(Uri, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0, CSharpVirtualDocumentSnapshot));
 
             var requestInvoker = new Mock<LSPRequestInvoker>(MockBehavior.Strict);
             requestInvoker
-                .Setup(r => r.ReinvokeRequestOnServerAsync<CompletionParams, SumType<CompletionItem[], CompletionList>?>(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CompletionParams>(), It.IsAny<CancellationToken>()))
-                .Callback<string, string, CompletionParams, CancellationToken>((method, clientName, completionParams, ct) =>
+                .Setup(r => r.ReinvokeRequestOnServerAsync<CompletionParams, SumType<CompletionItem[], CompletionList>?>(TextBuffer, It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CompletionParams>(), It.IsAny<CancellationToken>()))
+                .Callback<ITextBuffer, string, string, CompletionParams, CancellationToken>((textBuffer, method, clientName, completionParams, ct) =>
                 {
                     Assert.Equal(Methods.TextDocumentCompletionName, method);
                     Assert.Equal(RazorLSPConstants.RazorCSharpLanguageServerName, clientName);
                     called = true;
                 })
-                .Returns(Task.FromResult(new ReinvokeResponse<SumType<CompletionItem[], CompletionList>?>(_languageClient, expectedItems)));
+                .Returns(Task.FromResult(new ReinvocationResponse<SumType<CompletionItem[], CompletionList>?>(_languageClient, expectedItems)));
 
             var projectionResult = new ProjectionResult()
             {
@@ -1079,7 +1098,11 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
                 Position = new Position(0, 29)
             };
 
-            var documentSnapshot = new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0, snapshotContent: "@{ void M() { var __x = 1; __ } }");
+            var documentSnapshot = new TestLSPDocumentSnapshot(
+                new Uri("C:/path/file.razor"),
+                version: 0,
+                snapshotContent: "@{ void M() { var __x = 1; __ } }",
+                CSharpVirtualDocumentSnapshot);
             var documentManager = new TestDocumentManager();
             documentManager.AddDocument(Uri, documentSnapshot);
 
@@ -1088,14 +1111,14 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
             var navigatorSelector = BuildNavigatorSelector(wordRange);
             var requestInvoker = new Mock<LSPRequestInvoker>(MockBehavior.Strict);
             requestInvoker
-                .Setup(r => r.ReinvokeRequestOnServerAsync<CompletionParams, SumType<CompletionItem[], CompletionList>?>(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CompletionParams>(), It.IsAny<CancellationToken>()))
-                .Callback<string, string, CompletionParams, CancellationToken>((method, clientName, completionParams, ct) =>
+                .Setup(r => r.ReinvokeRequestOnServerAsync<CompletionParams, SumType<CompletionItem[], CompletionList>?>(TextBuffer, It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CompletionParams>(), It.IsAny<CancellationToken>()))
+                .Callback<ITextBuffer, string, string, CompletionParams, CancellationToken>((textBuffer, method, clientName, completionParams, ct) =>
                 {
                     Assert.Equal(Methods.TextDocumentCompletionName, method);
                     Assert.Equal(RazorLSPConstants.RazorCSharpLanguageServerName, clientName);
                     called = true;
                 })
-                .Returns(Task.FromResult(new ReinvokeResponse<SumType<CompletionItem[], CompletionList>?>(_languageClient, expectedItems)));
+                .Returns(Task.FromResult(new ReinvocationResponse<SumType<CompletionItem[], CompletionList>?>(_languageClient, expectedItems)));
 
             var projectionResult = new ProjectionResult()
             {
@@ -1135,18 +1158,18 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
             };
 
             var documentManager = new TestDocumentManager();
-            documentManager.AddDocument(Uri, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0));
+            documentManager.AddDocument(Uri, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0, HtmlVirtualDocumentSnapshot));
 
             var requestInvoker = new Mock<LSPRequestInvoker>(MockBehavior.Strict);
             requestInvoker
-                .Setup(r => r.ReinvokeRequestOnServerAsync<CompletionParams, SumType<CompletionItem[], CompletionList>?>(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CompletionParams>(), It.IsAny<CancellationToken>()))
-                .Callback<string, string, CompletionParams, CancellationToken>((method, clientName, completionParams, ct) =>
+                .Setup(r => r.ReinvokeRequestOnServerAsync<CompletionParams, SumType<CompletionItem[], CompletionList>?>(TextBuffer, It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CompletionParams>(), It.IsAny<CancellationToken>()))
+                .Callback<ITextBuffer, string, string, CompletionParams, CancellationToken>((textBuffer, method, clientName, completionParams, ct) =>
                 {
                     Assert.Equal(Methods.TextDocumentCompletionName, method);
                     Assert.Equal(RazorLSPConstants.HtmlLanguageServerName, clientName);
                     called = true;
                 })
-                .Returns(Task.FromResult(new ReinvokeResponse<SumType<CompletionItem[], CompletionList>?>(_languageClient, new[] { expectedItem })));
+                .Returns(Task.FromResult(new ReinvocationResponse<SumType<CompletionItem[], CompletionList>?>(_languageClient, new[] { expectedItem })));
 
             var projectionResult = new ProjectionResult()
             {
@@ -1235,18 +1258,18 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
             };
 
             var documentManager = new TestDocumentManager();
-            documentManager.AddDocument(Uri, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0));
+            documentManager.AddDocument(Uri, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0, HtmlVirtualDocumentSnapshot, CSharpVirtualDocumentSnapshot));
 
             var requestInvoker = new Mock<LSPRequestInvoker>(MockBehavior.Strict);
             requestInvoker
-                .Setup(r => r.ReinvokeRequestOnServerAsync<CompletionParams, SumType<CompletionItem[], CompletionList>?>(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CompletionParams>(), It.IsAny<CancellationToken>()))
-                .Callback<string, string, CompletionParams, CancellationToken>((method, clientName, completionParams, ct) =>
+                .Setup(r => r.ReinvokeRequestOnServerAsync<CompletionParams, SumType<CompletionItem[], CompletionList>?>(TextBuffer, It.IsAny<string>(), It.IsAny<string>(), It.IsAny<CompletionParams>(), It.IsAny<CancellationToken>()))
+                .Callback<ITextBuffer, string, string, CompletionParams, CancellationToken>((textBuffer, method, clientName, completionParams, ct) =>
                 {
                     Assert.Equal(Methods.TextDocumentCompletionName, method);
                     Assert.Equal(RazorLSPConstants.RazorCSharpLanguageServerName, clientName);
                     called = true;
                 })
-                .Returns(Task.FromResult(new ReinvokeResponse<SumType<CompletionItem[], CompletionList>?>(_languageClient, new[] { expectedItem })));
+                .Returns(Task.FromResult(new ReinvocationResponse<SumType<CompletionItem[], CompletionList>?>(_languageClient, new[] { expectedItem })));
 
             var projectionResult = new ProjectionResult()
             {
@@ -1293,7 +1316,7 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
             };
 
             var documentManager = new TestDocumentManager();
-            documentManager.AddDocument(Uri, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0));
+            documentManager.AddDocument(Uri, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0, CSharpVirtualDocumentSnapshot));
 
             var requestInvoker = new Mock<LSPRequestInvoker>(MockBehavior.Strict);
 
@@ -1306,7 +1329,7 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
             var completionHandler = new CompletionHandler(JoinableTaskContext, requestInvoker.Object, documentManager, projectionProvider.Object, TextStructureNavigatorSelectorService, CompletionRequestContextCache, FormattingOptionsProvider, LoggerProvider);
 
             // Act
-            var (succeeded, result) = await completionHandler.TryGetProvisionalCompletionsAsync(completionRequest, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0), projectionResult, CancellationToken.None).ConfigureAwait(false);
+            var (succeeded, result) = await completionHandler.TryGetProvisionalCompletionsAsync(completionRequest, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0, CSharpVirtualDocumentSnapshot), projectionResult, CancellationToken.None).ConfigureAwait(false);
 
             // Assert
             Assert.False(succeeded);
@@ -1329,7 +1352,7 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
             };
 
             var documentManager = new TestDocumentManager();
-            documentManager.AddDocument(Uri, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0));
+            documentManager.AddDocument(Uri, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0, CSharpVirtualDocumentSnapshot));
 
             var requestInvoker = new Mock<LSPRequestInvoker>(MockBehavior.Strict);
 
@@ -1342,7 +1365,7 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
             var completionHandler = new CompletionHandler(JoinableTaskContext, requestInvoker.Object, documentManager, projectionProvider.Object, TextStructureNavigatorSelectorService, CompletionRequestContextCache, FormattingOptionsProvider, LoggerProvider);
 
             // Act
-            var (succeeded, result) = await completionHandler.TryGetProvisionalCompletionsAsync(completionRequest, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0), projectionResult, CancellationToken.None).ConfigureAwait(false);
+            var (succeeded, result) = await completionHandler.TryGetProvisionalCompletionsAsync(completionRequest, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0, CSharpVirtualDocumentSnapshot), projectionResult, CancellationToken.None).ConfigureAwait(false);
 
             // Assert
             Assert.False(succeeded);
@@ -1365,7 +1388,7 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
             };
 
             var documentManager = new TestDocumentManager();
-            documentManager.AddDocument(Uri, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0));
+            documentManager.AddDocument(Uri, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0, CSharpVirtualDocumentSnapshot));
 
             var requestInvoker = new Mock<LSPRequestInvoker>(MockBehavior.Strict);
 
@@ -1384,7 +1407,7 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
             var completionHandler = new CompletionHandler(JoinableTaskContext, requestInvoker.Object, documentManager, projectionProvider.Object, TextStructureNavigatorSelectorService, CompletionRequestContextCache, FormattingOptionsProvider, LoggerProvider);
 
             // Act
-            var (succeeded, result) = await completionHandler.TryGetProvisionalCompletionsAsync(completionRequest, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0), projectionResult, CancellationToken.None).ConfigureAwait(false);
+            var (succeeded, result) = await completionHandler.TryGetProvisionalCompletionsAsync(completionRequest, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0, CSharpVirtualDocumentSnapshot), projectionResult, CancellationToken.None).ConfigureAwait(false);
 
             // Assert
             Assert.False(succeeded);
@@ -1407,7 +1430,7 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
             };
 
             var documentManager = new TestDocumentManager();
-            documentManager.AddDocument(Uri, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0));
+            documentManager.AddDocument(Uri, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0, CSharpVirtualDocumentSnapshot));
 
             var requestInvoker = new Mock<LSPRequestInvoker>(MockBehavior.Strict);
 
@@ -1426,7 +1449,7 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
             var completionHandler = new CompletionHandler(JoinableTaskContext, requestInvoker.Object, documentManager, projectionProvider.Object, TextStructureNavigatorSelectorService, CompletionRequestContextCache, FormattingOptionsProvider, LoggerProvider);
 
             // Act
-            var (succeeded, result) = await completionHandler.TryGetProvisionalCompletionsAsync(completionRequest, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0), projectionResult, CancellationToken.None).ConfigureAwait(false);
+            var (succeeded, result) = await completionHandler.TryGetProvisionalCompletionsAsync(completionRequest, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0, CSharpVirtualDocumentSnapshot), projectionResult, CancellationToken.None).ConfigureAwait(false);
 
             // Assert
             Assert.False(succeeded);
@@ -1457,17 +1480,18 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
             var requestInvoker = new Mock<LSPRequestInvoker>(MockBehavior.Strict);
             requestInvoker
                 .Setup(r => r.ReinvokeRequestOnServerAsync<CompletionParams, SumType<CompletionItem[], CompletionList>?>(
+                    TextBuffer,
                     It.IsAny<string>(),
                     RazorLSPConstants.CSharpContentTypeName,
                     It.IsAny<CompletionParams>(),
                     It.IsAny<CancellationToken>()))
-                .Callback<string, string, CompletionParams, CancellationToken>((method, clientName, completionParams, ct) =>
+                .Callback<ITextBuffer, string, string, CompletionParams, CancellationToken>((textBuffer, method, clientName, completionParams, ct) =>
                 {
                     Assert.Equal(Methods.TextDocumentCompletionName, method);
                     Assert.Equal(RazorLSPConstants.RazorCSharpLanguageServerName, clientName);
                     languageServerCalled = true;
                 })
-                .Returns(Task.FromResult(new ReinvokeResponse<SumType<CompletionItem[], CompletionList>?>(_languageClient, new[] { expectedItem })));
+                .Returns(Task.FromResult(new ReinvocationResponse<SumType<CompletionItem[], CompletionList>?>(_languageClient, new[] { expectedItem })));
 
             var projectionResult = new ProjectionResult()
             {
@@ -1488,7 +1512,7 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
             var completionHandler = new CompletionHandler(JoinableTaskContext, requestInvoker.Object, documentManager, projectionProvider.Object, TextStructureNavigatorSelectorService, CompletionRequestContextCache, FormattingOptionsProvider, LoggerProvider);
 
             // Act
-            var (succeeded, result) = await completionHandler.TryGetProvisionalCompletionsAsync(completionRequest, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0), projectionResult, CancellationToken.None).ConfigureAwait(false);
+            var (succeeded, result) = await completionHandler.TryGetProvisionalCompletionsAsync(completionRequest, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0, CSharpVirtualDocumentSnapshot), projectionResult, CancellationToken.None).ConfigureAwait(false);
 
             // Assert
             Assert.False(succeeded);
@@ -1521,17 +1545,18 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
             var requestInvoker = new Mock<LSPRequestInvoker>(MockBehavior.Strict);
             requestInvoker
                 .Setup(r => r.ReinvokeRequestOnServerAsync<CompletionParams, SumType<CompletionItem[], CompletionList>?>(
+                    TextBuffer,
                     It.IsAny<string>(),
                     RazorLSPConstants.RazorCSharpLanguageServerName,
                     It.IsAny<CompletionParams>(),
                     It.IsAny<CancellationToken>()))
-                .Callback<string, string, CompletionParams, CancellationToken>((method, clientName, completionParams, ct) =>
+                .Callback<ITextBuffer, string, string, CompletionParams, CancellationToken>((textBuffer, method, clientName, completionParams, ct) =>
                 {
                     Assert.Equal(Methods.TextDocumentCompletionName, method);
                     Assert.Equal(RazorLSPConstants.RazorCSharpLanguageServerName, clientName);
                     languageServerCalled = true;
                 })
-                .Returns(Task.FromResult(new ReinvokeResponse<SumType<CompletionItem[], CompletionList>?>(_languageClient, new[] { expectedItem })));
+                .Returns(Task.FromResult(new ReinvocationResponse<SumType<CompletionItem[], CompletionList>?>(_languageClient, new[] { expectedItem })));
 
             var projectionResult = new ProjectionResult()
             {
@@ -1552,7 +1577,7 @@ namespace Microsoft.VisualStudio.LanguageServerClient.Razor.HtmlCSharp
             var completionHandler = new CompletionHandler(JoinableTaskContext, requestInvoker.Object, documentManager, projectionProvider.Object, TextStructureNavigatorSelectorService, CompletionRequestContextCache, FormattingOptionsProvider, LoggerProvider);
 
             // Act
-            var (succeeded, result) = await completionHandler.TryGetProvisionalCompletionsAsync(completionRequest, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0), projectionResult, CancellationToken.None).ConfigureAwait(false);
+            var (succeeded, result) = await completionHandler.TryGetProvisionalCompletionsAsync(completionRequest, new TestLSPDocumentSnapshot(new Uri("C:/path/file.razor"), 0, CSharpVirtualDocumentSnapshot), projectionResult, CancellationToken.None).ConfigureAwait(false);
 
             // Assert
             Assert.True(succeeded);