Add IRelatedDocumentsService EA wrapper for Copilot

src/EditorFeatures/ExternalAccess/Copilot/Internal/RelatedDocuments/CSharpCopilotRelatedDocumentsService.cs

@@ -0,0 +1,31 @@
+// 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.Immutable;
+using System.Composition;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.CodeAnalysis.ExternalAccess.Copilot.RelatedDocuments;
+using Microsoft.CodeAnalysis.Host.Mef;
+using Microsoft.CodeAnalysis.RelatedDocuments;
+using Microsoft.CodeAnalysis.Shared.Extensions;
+
+namespace Microsoft.CodeAnalysis.ExternalAccess.Copilot.Internal.RelatedDocuments;
+
+[ExportLanguageService(typeof(ICopilotRelatedDocumentsService), language: LanguageNames.CSharp), Shared]
+internal sealed class CSharpCopilotRelatedDocumentsService : ICopilotRelatedDocumentsService
+{
+    [ImportingConstructor]
+    [Obsolete(MefConstruction.ImportingConstructorMessage, error: true)]
+    public CSharpCopilotRelatedDocumentsService()
+    {
+    }
+
+    public ValueTask GetRelatedDocumentIdsAsync(Document document, int position, Func<ImmutableArray<DocumentId>, CancellationToken, ValueTask> callbackAsync, CancellationToken cancellationToken)
+    {
+        var service = document.GetRequiredLanguageService<IRelatedDocumentsService>();
+        return service.GetRelatedDocumentIdsAsync(document, position, callbackAsync, cancellationToken);
+    }
+}

src/EditorFeatures/ExternalAccess/Copilot/InternalAPI.Unshipped.txt

@@ -12,6 +12,8 @@ Microsoft.CodeAnalysis.ExternalAccess.Copilot.IExternalCSharpCopilotCodeAnalysis
 Microsoft.CodeAnalysis.ExternalAccess.Copilot.IExternalCSharpCopilotCodeAnalysisService.IsAnyExclusionAsync(System.Threading.CancellationToken cancellationToken) -> System.Threading.Tasks.Task<bool>!
 Microsoft.CodeAnalysis.ExternalAccess.Copilot.IExternalCSharpCopilotCodeAnalysisService.IsAvailableAsync(System.Threading.CancellationToken cancellation) -> System.Threading.Tasks.Task<bool>!
 Microsoft.CodeAnalysis.ExternalAccess.Copilot.IExternalCSharpCopilotCodeAnalysisService.StartRefinementSessionAsync(Microsoft.CodeAnalysis.Document! oldDocument, Microsoft.CodeAnalysis.Document! newDocument, Microsoft.CodeAnalysis.Diagnostic? primaryDiagnostic, System.Threading.CancellationToken cancellationToken) -> System.Threading.Tasks.Task!
+Microsoft.CodeAnalysis.ExternalAccess.Copilot.RelatedDocuments.ICopilotRelatedDocumentsService
+Microsoft.CodeAnalysis.ExternalAccess.Copilot.RelatedDocuments.ICopilotRelatedDocumentsService.GetRelatedDocumentIdsAsync(Microsoft.CodeAnalysis.Document! document, int position, System.Func<System.Collections.Immutable.ImmutableArray<Microsoft.CodeAnalysis.DocumentId!>, System.Threading.CancellationToken, System.Threading.Tasks.ValueTask>! callbackAsync, System.Threading.CancellationToken cancellationToken) -> System.Threading.Tasks.ValueTask
 override Microsoft.CodeAnalysis.ExternalAccess.Copilot.CopilotChecksumWrapper.Equals(object? obj) -> bool
 override Microsoft.CodeAnalysis.ExternalAccess.Copilot.CopilotChecksumWrapper.GetHashCode() -> int
 static Microsoft.CodeAnalysis.ExternalAccess.Copilot.CopilotChecksumWrapper.Create(System.Collections.Immutable.ImmutableArray<string!> values) -> Microsoft.CodeAnalysis.ExternalAccess.Copilot.CopilotChecksumWrapper!

src/EditorFeatures/ExternalAccess/Copilot/RelatedDocuments/ICopilotRelatedDocumentsService.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;
+using System.Collections.Immutable;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.CodeAnalysis.Host;
+
+namespace Microsoft.CodeAnalysis.ExternalAccess.Copilot.RelatedDocuments;
+
+internal interface ICopilotRelatedDocumentsService : ILanguageService
+{
+    ValueTask GetRelatedDocumentIdsAsync(
+        Document document, int position, Func<ImmutableArray<DocumentId>, CancellationToken, ValueTask> callbackAsync, CancellationToken cancellationToken);
+}