Introduce EA layer for TS to integrate with classification

Author: CyrusNajmabadi

src/Features/Core/Portable/ExternalAccess/VSTypeScript/Api/IVSTypeScriptClassificationService.cs

@@ -0,0 +1,17 @@
+// 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.Collections.Generic;
+using System.Collections.Immutable;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.CodeAnalysis.Classification;
+using Microsoft.CodeAnalysis.Text;
+
+namespace Microsoft.CodeAnalysis.ExternalAccess.VSTypeScript.Api;
+
+internal interface IVSTypeScriptClassificationService
+{
+    Task AddSemanticClassificationsAsync(Document document, ImmutableArray<TextSpan> textSpans, List<ClassifiedSpan> result, CancellationToken cancellationToken);
+}

src/Features/Core/Portable/ExternalAccess/VSTypeScript/VSTypeScriptClassificationService.cs

@@ -0,0 +1,78 @@
+// 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;
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.Composition;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.CodeAnalysis.Classification;
+using Microsoft.CodeAnalysis.Collections;
+using Microsoft.CodeAnalysis.ExternalAccess.VSTypeScript.Api;
+using Microsoft.CodeAnalysis.Host;
+using Microsoft.CodeAnalysis.Host.Mef;
+using Microsoft.CodeAnalysis.Text;
+
+namespace Microsoft.CodeAnalysis.ExternalAccess.VSTypeScript;
+
+[ExportLanguageService(typeof(IClassificationService), InternalLanguageNames.TypeScript), Shared]
+internal sealed class VSTypeScriptClassificationService : IClassificationService
+{
+    private readonly IVSTypeScriptClassificationService? _classificationService;
+
+    [ImportingConstructor]
+    [Obsolete(MefConstruction.ImportingConstructorMessage, error: true)]
+    public VSTypeScriptClassificationService(
+        [Import(AllowDefault = true)] IVSTypeScriptClassificationService? classificationService)
+    {
+        _classificationService = classificationService;
+    }
+
+    public void AddLexicalClassifications(SourceText text, TextSpan textSpan, SegmentedList<ClassifiedSpan> result, CancellationToken cancellationToken)
+    {
+    }
+
+    public void AddSyntacticClassifications(SolutionServices services, SyntaxNode? root, ImmutableArray<TextSpan> textSpans, SegmentedList<ClassifiedSpan> result, CancellationToken cancellationToken)
+    {
+    }
+
+    public Task AddSyntacticClassificationsAsync(Document document, ImmutableArray<TextSpan> textSpans, SegmentedList<ClassifiedSpan> result, CancellationToken cancellationToken)
+    {
+        return Task.CompletedTask;
+    }
+
+    public Task AddEmbeddedLanguageClassificationsAsync(Document document, ImmutableArray<TextSpan> textSpans, ClassificationOptions options, SegmentedList<ClassifiedSpan> result, CancellationToken cancellationToken)
+    {
+        return Task.CompletedTask;
+    }
+
+    public ClassifiedSpan AdjustStaleClassification(SourceText text, ClassifiedSpan classifiedSpan)
+    {
+        return classifiedSpan;
+    }
+
+    public ValueTask<TextChangeRange?> ComputeSyntacticChangeRangeAsync(Document oldDocument, Document newDocument, TimeSpan timeout, CancellationToken cancellationToken)
+    {
+        return default;
+    }
+
+    public TextChangeRange? ComputeSyntacticChangeRange(SolutionServices workspace, SyntaxNode oldRoot, SyntaxNode newRoot, TimeSpan timeout, CancellationToken cancellationToken)
+    {
+        return null;
+    }
+
+    public async Task AddSemanticClassificationsAsync(Document document, ImmutableArray<TextSpan> textSpans, ClassificationOptions options, SegmentedList<ClassifiedSpan> result, CancellationToken cancellationToken)
+    {
+        if (_classificationService is null)
+            return;
+
+        using var _ = SharedPools.BigDefault<List<ClassifiedSpan>>().GetPooledObject(out var list);
+
+        await _classificationService.AddSemanticClassificationsAsync(document, textSpans, list, cancellationToken).ConfigureAwait(false);
+
+        foreach (var classifiedSpan in list)
+            result.Add(classifiedSpan);
+    }
+}

src/Features/Core/Portable/ExternalAccess/VSTypeScript/VSTypeScriptCommentSelectionService.cs

@@ -4,6 +4,7 @@
 
 using System;
 using System.Composition;
+using Microsoft.CodeAnalysis.Classification;
 using Microsoft.CodeAnalysis.CommentSelection;
 using Microsoft.CodeAnalysis.Host.Mef;