Make TryGetProvisionalCompletionInfoAsync synchronous

The only reason this method was async was to call the IDocumentMappingService extension method, GetPositionInfoAsync. However, the reason *that* extension method is async is to call GetCodeDocumentAsync(). Ultimately, this method can be made synchronous by passing RazorCodeDocument to it.

Author: DustinCampbell

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

@@ -61,17 +61,13 @@ public DelegatedCompletionListProvider(
             return null;
         }
 
-        var provisionalCompletion = await DelegatedCompletionHelper.TryGetProvisionalCompletionInfoAsync(
-            documentContext,
-            completionContext,
-            positionInfo,
-            _documentMappingService,
-            cancellationToken).ConfigureAwait(false);
+        var codeDocument = await documentContext.GetCodeDocumentAsync(cancellationToken).ConfigureAwait(false);
+
         TextEdit? provisionalTextEdit = null;
-        if (provisionalCompletion is { } provisionalCompletionValue)
+        if (DelegatedCompletionHelper.TryGetProvisionalCompletionInfo(codeDocument, completionContext, positionInfo, _documentMappingService, out var provisionalCompletion))
         {
-            provisionalTextEdit = provisionalCompletionValue.ProvisionalTextEdit;
-            positionInfo = provisionalCompletionValue.DocumentPositionInfo;
+            provisionalTextEdit = provisionalCompletion.ProvisionalTextEdit;
+            positionInfo = provisionalCompletion.DocumentPositionInfo;
         }
 
         if (DelegatedCompletionHelper.RewriteContext(completionContext, positionInfo.LanguageKind, _triggerAndCommitCharacters) is not { } rewrittenContext)
@@ -81,8 +77,6 @@ public DelegatedCompletionListProvider(
 
         completionContext = rewrittenContext;
 
-        var codeDocument = await documentContext.GetCodeDocumentAsync(cancellationToken).ConfigureAwait(false);
-
         // It's a bit confusing, but we have two different "add snippets" options - one is a part of
         // RazorCompletionOptions and becomes a part of RazorCompletionContext and is used by
         // RazorCompletionFactsService, and the second one below that's used for delegated completion

src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/Completion/Delegation/DelegatedCompletionHelper.cs

@@ -3,11 +3,8 @@
 
 using System.Collections.Immutable;
 using System.Diagnostics;
-using System.Threading;
-using System.Threading.Tasks;
 using Microsoft.AspNetCore.Razor.Language;
 using Microsoft.CodeAnalysis.Razor.DocumentMapping;
-using Microsoft.CodeAnalysis.Razor.ProjectSystem;
 using Microsoft.CodeAnalysis.Razor.Protocol;
 using Microsoft.CodeAnalysis.Razor.Protocol.Completion;
 using Microsoft.VisualStudio.LanguageServer.Protocol;
@@ -159,34 +156,34 @@ public static VSInternalCompletionList RewriteHtmlResponse(
     /// to C# and will return a temporary edit that should be made to the generated document
     /// in order to add the '.' to the generated C# contents.
     /// </remarks>
-    public static async Task<CompletionPositionInfo?> TryGetProvisionalCompletionInfoAsync(
-        DocumentContext documentContext,
+    public static bool TryGetProvisionalCompletionInfo(
+        RazorCodeDocument codeDocument,
         VSInternalCompletionContext completionContext,
         DocumentPositionInfo originalPositionInfo,
         IDocumentMappingService documentMappingService,
-        CancellationToken cancellationToken)
+        out CompletionPositionInfo result)
     {
+        result = default;
+
         if (originalPositionInfo.LanguageKind != RazorLanguageKind.Html ||
             completionContext.TriggerKind != CompletionTriggerKind.TriggerCharacter ||
             completionContext.TriggerCharacter != ".")
         {
             // Invalid provisional completion context
-            return null;
+            return false;
         }
 
         if (originalPositionInfo.Position.Character == 0)
         {
             // We're at the start of line. Can't have provisional completions here.
-            return null;
+            return false;
         }
 
-        var previousCharacterPositionInfo = await documentMappingService
-            .GetPositionInfoAsync(documentContext, originalPositionInfo.HostDocumentIndex - 1, cancellationToken)
-            .ConfigureAwait(false);
+        var previousCharacterPositionInfo = documentMappingService.GetPositionInfo(codeDocument, originalPositionInfo.HostDocumentIndex - 1);
 
         if (previousCharacterPositionInfo.LanguageKind != RazorLanguageKind.CSharp)
         {
-            return null;
+            return false;
         }
 
         var previousPosition = previousCharacterPositionInfo.Position;
@@ -202,7 +199,8 @@ public static VSInternalCompletionList RewriteHtmlResponse(
                 previousPosition.Character + 1),
             previousCharacterPositionInfo.HostDocumentIndex + 1);
 
-        return new CompletionPositionInfo(addProvisionalDot, provisionalPositionInfo, ShouldIncludeDelegationSnippets: false);
+        result = new CompletionPositionInfo(addProvisionalDot, provisionalPositionInfo, ShouldIncludeDelegationSnippets: false);
+        return true;
     }
 
     public static bool ShouldIncludeSnippets(RazorCodeDocument razorCodeDocument, int absoluteIndex)

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

@@ -63,18 +63,10 @@ protected override IRemoteCompletionService CreateService(in ServiceArgs args)
         var positionInfo = GetPositionInfo(codeDocument, index);
 
         if (positionInfo.LanguageKind != RazorLanguageKind.Razor
-           && await DelegatedCompletionHelper.TryGetProvisionalCompletionInfoAsync(
-                remoteDocumentContext,
-                completionContext,
-                positionInfo,
-                DocumentMappingService,
-                cancellationToken)
-                .ConfigureAwait(false) is { } provisionalCompletionInfo)
+            && DelegatedCompletionHelper.TryGetProvisionalCompletionInfo(
+                codeDocument, completionContext, positionInfo, DocumentMappingService, out var provisionalCompletionInfo))
         {
-            return new CompletionPositionInfo(
-                provisionalCompletionInfo.ProvisionalTextEdit,
-                provisionalCompletionInfo.DocumentPositionInfo,
-                ShouldIncludeDelegationSnippets: false);
+            return provisionalCompletionInfo with { ShouldIncludeDelegationSnippets = false };
         }
 
         var shouldIncludeSnippets = positionInfo.LanguageKind == RazorLanguageKind.Html