Fix completion resolve for provisional completion

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/Completion/Delegation/DelegatedCompletionListProvider.cs

@@ -116,7 +116,7 @@ internal class DelegatedCompletionListProvider(
             ? DelegatedCompletionHelper.RewriteCSharpResponse(delegatedResponse, absoluteIndex, codeDocument, positionInfo.Position, razorCompletionOptions)
             : DelegatedCompletionHelper.RewriteHtmlResponse(delegatedResponse, razorCompletionOptions);
 
-        var resolutionContext = new DelegatedCompletionResolutionContext(identifier, positionInfo.LanguageKind, rewrittenResponse.Data ?? rewrittenResponse.ItemDefaults?.Data);
+        var resolutionContext = new DelegatedCompletionResolutionContext(identifier, positionInfo.LanguageKind, rewrittenResponse.Data ?? rewrittenResponse.ItemDefaults?.Data, provisionalTextEdit);
         var resultId = _completionListCache.Add(rewrittenResponse, resolutionContext);
         rewrittenResponse.SetResultId(resultId, clientCapabilities);
 

src/Razor/src/Microsoft.CodeAnalysis.Razor.CohostingShared/Completion/CohostDocumentCompletionEndpoint.cs

@@ -234,7 +234,7 @@ public ImmutableArray<Registration> GetRegistrations(VSInternalClientCapabilitie
         var rewrittenResponse = DelegatedCompletionHelper.RewriteHtmlResponse(result, razorCompletionOptions);
 
         var razorDocumentIdentifier = new TextDocumentIdentifierAndVersion(completionParams.TextDocument, Version: 0);
-        var resolutionContext = new DelegatedCompletionResolutionContext(razorDocumentIdentifier, RazorLanguageKind.Html, rewrittenResponse.Data ?? rewrittenResponse.ItemDefaults?.Data);
+        var resolutionContext = new DelegatedCompletionResolutionContext(razorDocumentIdentifier, RazorLanguageKind.Html, rewrittenResponse.Data ?? rewrittenResponse.ItemDefaults?.Data, ProvisionalTextEdit: null);
         var resultId = _completionListCache.Add(rewrittenResponse, resolutionContext);
         rewrittenResponse.SetResultId(resultId, _clientCapabilitiesService.ClientCapabilities);
 

src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/Protocol/DelegatedTypes.cs

@@ -71,7 +71,8 @@ internal record DelegatedMapCodeParams(
 internal record DelegatedCompletionResolutionContext(
     [property: JsonPropertyName("identifier")] TextDocumentIdentifierAndVersion Identifier,
     [property: JsonPropertyName("projectedKind")] RazorLanguageKind ProjectedKind,
-    [property: JsonPropertyName("originalCompletionListData")] object? OriginalCompletionListData) : ICompletionResolveContext;
+    [property: JsonPropertyName("originalCompletionListData")] object? OriginalCompletionListData,
+    [property: JsonPropertyName("provisionalTextEdit")] TextEdit? ProvisionalTextEdit) : ICompletionResolveContext;
 
 internal record DelegatedCompletionItemResolveParams(
     [property: JsonPropertyName("identifier")] TextDocumentIdentifierAndVersion Identifier,

src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/Completion/RemoteCompletionService.cs

@@ -149,6 +149,7 @@ private async ValueTask<Response> GetCompletionAsync(
                 completionContext,
                 razorCompletionOptions,
                 correlationId,
+                positionInfo.ProvisionalTextEdit,
                 cancellationToken)
                 .ConfigureAwait(false);
 
@@ -191,6 +192,7 @@ private async ValueTask<Response> GetCompletionAsync(
         CompletionContext completionContext,
         RazorCompletionOptions razorCompletionOptions,
         Guid correlationId,
+        TextEdit? provisionalTextEdit,
         CancellationToken cancellationToken)
     {
         var clientCapabilities = _clientCapabilitiesService.ClientCapabilities;
@@ -236,7 +238,7 @@ private async ValueTask<Response> GetCompletionAsync(
             mappedPosition,
             razorCompletionOptions);
 
-        var resolutionContext = new DelegatedCompletionResolutionContext(identifier, RazorLanguageKind.CSharp, rewrittenResponse.Data ?? rewrittenResponse.ItemDefaults?.Data);
+        var resolutionContext = new DelegatedCompletionResolutionContext(identifier, RazorLanguageKind.CSharp, rewrittenResponse.Data ?? rewrittenResponse.ItemDefaults?.Data, provisionalTextEdit);
         var resultId = _completionListCache.Add(rewrittenResponse, resolutionContext);
         rewrittenResponse.SetResultId(resultId, clientCapabilities);
 
@@ -326,7 +328,7 @@ private async ValueTask<VSInternalCompletionItem> ResolveCSharpCompletionItemAsy
             }
 
             var documentSnapshot = context.Snapshot;
-            var generatedDocument = await documentSnapshot.GetGeneratedDocumentAsync(cancellationToken).ConfigureAwait(false);
+            var generatedDocument = await GetCSharpGeneratedDocumentAsync(documentSnapshot, resolutionContext.ProvisionalTextEdit, cancellationToken).ConfigureAwait(false);
 
             var clientCapabilities = _clientCapabilitiesService.ClientCapabilities;
             var completionListSetting = clientCapabilities.TextDocument?.Completion;

src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Completion/Delegation/DelegatedCompletionItemResolverTest.NetFx.cs

@@ -151,7 +151,7 @@ public async Task ResolveAsync_UsesItemsData()
             Data = expectedData,
         };
         var containingCompletionList = new RazorVSInternalCompletionList() { Items = [item], Data = new object() };
-        var originalRequestContext = new DelegatedCompletionResolutionContext(_csharpCompletionParams.Identifier, _csharpCompletionParams.ProjectedKind, new object());
+        var originalRequestContext = new DelegatedCompletionResolutionContext(_csharpCompletionParams.Identifier, _csharpCompletionParams.ProjectedKind, new object(), ProvisionalTextEdit: null);
 
         // Act
         await resolver.ResolveAsync(
@@ -176,7 +176,7 @@ public async Task ResolveAsync_InheritsOriginalCompletionListData()
         var resolver = new DelegatedCompletionItemResolver(DocumentContextFactory, formattingService, DocumentMappingService, optionsMonitor, clientConnection, LoggerFactory);
         var item = new VSInternalCompletionItem();
         var containingCompletionList = new RazorVSInternalCompletionList() { Items = [item], Data = new object() };
-        var originalRequestContext = new DelegatedCompletionResolutionContext(_csharpCompletionParams.Identifier, _csharpCompletionParams.ProjectedKind, expectedData);
+        var originalRequestContext = new DelegatedCompletionResolutionContext(_csharpCompletionParams.Identifier, _csharpCompletionParams.ProjectedKind, expectedData, ProvisionalTextEdit: null);
 
         // Act
         await resolver.ResolveAsync(item, containingCompletionList, originalRequestContext, s_clientCapabilities, _componentAvailabilityService, DisposalToken);
@@ -282,7 +282,7 @@ Task FooAsync()
 
         Assert.NotNull(item);
 
-        var originalRequestContext = new DelegatedCompletionResolutionContext(_csharpCompletionParams.Identifier, _csharpCompletionParams.ProjectedKind, containingCompletionList.Data);
+        var originalRequestContext = new DelegatedCompletionResolutionContext(_csharpCompletionParams.Identifier, _csharpCompletionParams.ProjectedKind, containingCompletionList.Data, ProvisionalTextEdit: null);
         var resolvedItem = await resolver.ResolveAsync(
             item, containingCompletionList, originalRequestContext, s_clientCapabilities, _componentAvailabilityService, DisposalToken);
 
@@ -334,7 +334,7 @@ public async Task ResolveAsync_Html_Resolves()
         var resolver = new DelegatedCompletionItemResolver(DocumentContextFactory, formattingService, DocumentMappingService, optionsMonitor, clientConnection, LoggerFactory);
         var item = new VSInternalCompletionItem();
         var containingCompletionList = new RazorVSInternalCompletionList() { Items = [item] };
-        var originalRequestContext = new DelegatedCompletionResolutionContext(_htmlCompletionParams.Identifier, _htmlCompletionParams.ProjectedKind, new object());
+        var originalRequestContext = new DelegatedCompletionResolutionContext(_htmlCompletionParams.Identifier, _htmlCompletionParams.ProjectedKind, new object(), ProvisionalTextEdit: null);
 
         // Act
         var resolvedItem = await resolver.ResolveAsync(
@@ -363,7 +363,7 @@ private async Task<VSInternalCompletionItem> ResolveCompletionItemAsync(string c
         var resolver = new DelegatedCompletionItemResolver(documentContextFactory, formattingService, DocumentMappingService, optionsMonitor, clientConnection, LoggerFactory);
         var containingCompletionList = await GetCompletionListAndOriginalParamsAsync(cursorPosition, codeDocument, csharpServer);
 
-        var originalRequestContext = new DelegatedCompletionResolutionContext(_csharpCompletionParams.Identifier, _csharpCompletionParams.ProjectedKind, containingCompletionList.Data);
+        var originalRequestContext = new DelegatedCompletionResolutionContext(_csharpCompletionParams.Identifier, _csharpCompletionParams.ProjectedKind, containingCompletionList.Data, ProvisionalTextEdit: null);
         var item = containingCompletionList.Items.FirstOrDefault(item => item.Label == itemToResolve);
 
         if (item is null)

src/Razor/test/Microsoft.VisualStudioCode.RazorExtension.Test/Endpoints/Shared/CohostDocumentCompletionEndpointTest.cs

@@ -123,7 +123,16 @@ The end.
                 TriggerCharacter = ".",
                 TriggerKind = CompletionTriggerKind.TriggerCharacter
             },
-            expectedItemLabels: ["DaysInMonth", "IsLeapYear", "Now"]);
+            expectedItemLabels: ["DaysInMonth", "IsLeapYear", "Now"],
+            itemToResolve: "Now",
+            expectedResolvedItemDescription: "DateTime DateTime.Now { get; }",
+            expected: """
+            This is a Razor document.
+
+            <div>@DateTime.Now</div>
+
+            The end.
+            """);
     }
 
     [Fact]
@@ -1150,9 +1159,17 @@ private async Task VerifyCompletionResolveAsync(CodeAnalysis.TextDocument docume
             var insertIndex = text.GetRequiredAbsoluteIndex(position);
             changedText = text.WithChanges(new TextChange(new TextSpan(insertIndex, 0), insertText));
         }
+        else if (result.Label is { } label)
+        {
+            // We'll let expected be null here, since its just simple text insertion
+
+            var text = await document.GetTextAsync(DisposalToken).ConfigureAwait(false);
+            var insertIndex = text.GetRequiredAbsoluteIndex(position);
+            changedText = text.WithChanges(new TextChange(new TextSpan(insertIndex, 0), label));
+        }
         else if (expected is not null)
         {
-            Assert.Fail("Expected a TextEdit or Command with TextEdit, but got none. Presumably resolve failed. Result: " + JsonSerializer.SerializeToElement(result).ToString());
+            Assert.Fail("Expected a TextEdit or Command with TextEdit, or InsertText, or Label, but got none. Presumably resolve failed. Result: " + JsonSerializer.SerializeToElement(result).ToString());
         }
 
         if (result.AdditionalTextEdits is not null)

src/Razor/test/Microsoft.VisualStudioCode.RazorExtension.Test/Endpoints/Shared/CohostDocumentCompletionResolveEndpointTest.cs

@@ -66,7 +66,8 @@ private async Task VerifyCompletionItemResolveAsync(TestCode input)
         var context = new DelegatedCompletionResolutionContext(
             textDocumentIdentifier,
             OriginalCompletionListData: null,
-            ProjectedKind: RazorLanguageKind.Html);
+            ProjectedKind: RazorLanguageKind.Html,
+            ProvisionalTextEdit: null);
 
         var list = new RazorVSInternalCompletionList
         {