Implement INavigateToItemProvider2 without requiring breaking API changes

src/EditorFeatures/Core.Wpf/NavigateTo/NavigateToItemProvider.Searcher.cs

@@ -2,6 +2,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Collections.Immutable;
 using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
@@ -108,7 +109,7 @@ private async Task SearchAsyncWorker(Project project)
                 {
                     using (cacheService.EnableCaching(project.Id))
                     {
-                        var service = project.LanguageServices.GetService<INavigateToSearchService>();
+                        var service = TryGetNavigateToSearchService(project);
                         if (service != null)
                         {
                             var searchTask = _currentDocument != null
@@ -128,6 +129,27 @@ private async Task SearchAsyncWorker(Project project)
                 }
             }
 
+            private static INavigateToSearchService_RemoveInterfaceAboveAndRenameThisAfterInternalsVisibleToUsersUpdate TryGetNavigateToSearchService(Project project)
+            {
+                var service = project.LanguageServices.GetService<INavigateToSearchService_RemoveInterfaceAboveAndRenameThisAfterInternalsVisibleToUsersUpdate>();
+                if (service != null)
+                {
+                    return service;
+                }
+
+#pragma warning disable CS0618 // Type or member is obsolete
+#pragma warning disable CS0612 // Type or member is obsolete
+                var legacyService = project.LanguageServices.GetService<INavigateToSearchService>();
+                if (legacyService != null)
+                {
+                    return new ShimNavigateToSearchService(legacyService);
+                }
+#pragma warning restore CS0612 // Type or member is obsolete
+#pragma warning restore CS0618 // Type or member is obsolete
+
+                return null;
+            }
+
             private void ReportMatchResult(Project project, INavigateToSearchResult result)
             {
                 var matchedSpans = result.NameMatchSpans.SelectAsArray(t => t.ToSpan());
@@ -182,6 +204,27 @@ private static string GetNavigateToLanguage(string languageName)
                         return languageName;
                 }
             }
+
+            [Obsolete]
+            private class ShimNavigateToSearchService : INavigateToSearchService_RemoveInterfaceAboveAndRenameThisAfterInternalsVisibleToUsersUpdate
+            {
+                private readonly INavigateToSearchService _navigateToSearchService;
+
+                public ShimNavigateToSearchService(INavigateToSearchService navigateToSearchService)
+                {
+                    _navigateToSearchService = navigateToSearchService;
+                }
+
+                public IImmutableSet<string> KindsProvided => ImmutableHashSet<string>.Empty;
+
+                public bool CanFilter => false;
+
+                public Task<ImmutableArray<INavigateToSearchResult>> SearchDocumentAsync(Document document, string searchPattern, ISet<string> kinds, CancellationToken cancellationToken)
+                    => _navigateToSearchService.SearchDocumentAsync(document, searchPattern, cancellationToken);
+
+                public Task<ImmutableArray<INavigateToSearchResult>> SearchProjectAsync(Project project, string searchPattern, ISet<string> kinds, CancellationToken cancellationToken)
+                    => _navigateToSearchService.SearchProjectAsync(project, searchPattern, cancellationToken);
+            }
         }
     }
 }

src/EditorFeatures/Core.Wpf/NavigateTo/NavigateToItemProvider.cs

@@ -2,11 +2,12 @@
 
 using System;
 using System.Collections.Generic;
-using System.Collections.Immutable;
 using System.Threading;
 using Microsoft.CodeAnalysis.Shared.TestHooks;
 using Microsoft.VisualStudio.Language.NavigateTo.Interfaces;
 using Roslyn.Utilities;
+using INavigateToSearchService = Microsoft.CodeAnalysis.NavigateTo.INavigateToSearchService;
+using INavigateToSearchService_RemoveInterfaceAboveAndRenameThisAfterInternalsVisibleToUsersUpdate = Microsoft.CodeAnalysis.NavigateTo.INavigateToSearchService_RemoveInterfaceAboveAndRenameThisAfterInternalsVisibleToUsersUpdate;
 
 namespace Microsoft.CodeAnalysis.Editor.Implementation.NavigateTo
 {
@@ -30,21 +31,58 @@ internal partial class NavigateToItemProvider : INavigateToItemProvider2
             _displayFactory = new NavigateToItemDisplayFactory();
         }
 
-        public ISet<string> KindsProvided { get; } = ImmutableHashSet.Create(
-            NavigateToItemKind.Class,
-            NavigateToItemKind.Constant,
-            NavigateToItemKind.Delegate,
-            NavigateToItemKind.Enum,
-            NavigateToItemKind.EnumItem,
-            NavigateToItemKind.Event,
-            NavigateToItemKind.Field,
-            NavigateToItemKind.Interface,
-            NavigateToItemKind.Method,
-            NavigateToItemKind.Module,
-            NavigateToItemKind.Property,
-            NavigateToItemKind.Structure);
-
-        public bool CanFilter => true;
+        public ISet<string> KindsProvided
+        {
+            get
+            {
+                var result = new HashSet<string>(StringComparer.Ordinal);
+                foreach (var project in _workspace.CurrentSolution.Projects)
+                {
+                    var navigateToSearchService = project.LanguageServices.GetService<INavigateToSearchService_RemoveInterfaceAboveAndRenameThisAfterInternalsVisibleToUsersUpdate>();
+                    if (navigateToSearchService != null)
+                    {
+                        result.UnionWith(navigateToSearchService.KindsProvided);
+                        continue;
+                    }
+                }
+
+                return result;
+            }
+        }
+
+        public bool CanFilter
+        {
+            get
+            {
+                foreach (var project in _workspace.CurrentSolution.Projects)
+                {
+                    var navigateToSearchService = project.LanguageServices.GetService<INavigateToSearchService_RemoveInterfaceAboveAndRenameThisAfterInternalsVisibleToUsersUpdate>();
+                    if (navigateToSearchService != null)
+                    {
+                        if (!navigateToSearchService.CanFilter)
+                        {
+                            return false;
+                        }
+
+                        continue;
+                    }
+
+#pragma warning disable CS0618 // Type or member is obsolete
+                    var legacyNavigateToSearchService = project.LanguageServices.GetService<INavigateToSearchService>();
+                    if (legacyNavigateToSearchService != null)
+                    {
+                        return false;
+                    }
+#pragma warning restore CS0618 // Type or member is obsolete
+
+                    // If we reach here, it means the current project does not support Navigate To, which is
+                    // functionally equivalent to supporting filtering.
+                }
+
+                // All projects either support filtering or do not support Navigate To at all
+                return true;
+            }
+        }
 
         public void StopSearch()
         {

src/Features/CSharp/Portable/NavigateTo/CSharpNavigateToSearchService.cs

@@ -6,7 +6,7 @@
 
 namespace Microsoft.CodeAnalysis.CSharp.NavigateTo
 {
-    [ExportLanguageService(typeof(INavigateToSearchService), LanguageNames.CSharp), Shared]
+    [ExportLanguageService(typeof(INavigateToSearchService_RemoveInterfaceAboveAndRenameThisAfterInternalsVisibleToUsersUpdate), LanguageNames.CSharp), Shared]
     internal class CSharpNavigateToSearchService : AbstractNavigateToSearchService
     {
     }

src/Features/Core/Portable/NavigateTo/AbstractNavigateToSearchService.cs

@@ -7,8 +7,24 @@
 
 namespace Microsoft.CodeAnalysis.NavigateTo
 {
-    internal abstract partial class AbstractNavigateToSearchService : INavigateToSearchService
+    internal abstract partial class AbstractNavigateToSearchService : INavigateToSearchService_RemoveInterfaceAboveAndRenameThisAfterInternalsVisibleToUsersUpdate
     {
+        public IImmutableSet<string> KindsProvided { get; } = ImmutableHashSet.Create(
+            NavigateToItemKind.Class,
+            NavigateToItemKind.Constant,
+            NavigateToItemKind.Delegate,
+            NavigateToItemKind.Enum,
+            NavigateToItemKind.EnumItem,
+            NavigateToItemKind.Event,
+            NavigateToItemKind.Field,
+            NavigateToItemKind.Interface,
+            NavigateToItemKind.Method,
+            NavigateToItemKind.Module,
+            NavigateToItemKind.Property,
+            NavigateToItemKind.Structure);
+
+        public bool CanFilter => true;
+
         public async Task<ImmutableArray<INavigateToSearchResult>> SearchDocumentAsync(
             Document document, string searchPattern, ISet<string> kinds, CancellationToken cancellationToken)
         {

src/Features/Core/Portable/NavigateTo/INavigateToSearchService.cs

 // Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
+using System;
 using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.Threading;
@@ -8,8 +9,25 @@
 
 namespace Microsoft.CodeAnalysis.NavigateTo
 {
+    [Obsolete("Use " + nameof(INavigateToSearchService_RemoveInterfaceAboveAndRenameThisAfterInternalsVisibleToUsersUpdate) + " instead.")]
     internal interface INavigateToSearchService : ILanguageService
     {
+        Task<ImmutableArray<INavigateToSearchResult>> SearchProjectAsync(Project project, string searchPattern, CancellationToken cancellationToken);
+        Task<ImmutableArray<INavigateToSearchResult>> SearchDocumentAsync(Document document, string searchPattern, CancellationToken cancellationToken);
+    }
+
+    internal interface INavigateToSearchService_RemoveInterfaceAboveAndRenameThisAfterInternalsVisibleToUsersUpdate : ILanguageService
+    {
+        IImmutableSet<string> KindsProvided
+        {
+            get;
+        }
+
+        bool CanFilter
+        {
+            get;
+        }
+
         Task<ImmutableArray<INavigateToSearchResult>> SearchProjectAsync(Project project, string searchPattern, ISet<string> kinds, CancellationToken cancellationToken);
         Task<ImmutableArray<INavigateToSearchResult>> SearchDocumentAsync(Document document, string searchPattern, ISet<string> kinds, CancellationToken cancellationToken);
     }

src/Features/VisualBasic/Portable/NavigateTo/VisualBasicNavigateToSearchService.vb

@@ -5,7 +5,7 @@ Imports Microsoft.CodeAnalysis.Host.Mef
 Imports Microsoft.CodeAnalysis.NavigateTo
 
 Namespace Microsoft.CodeAnalysis.VisualBasic.NavigateTo
-    <ExportLanguageService(GetType(INavigateToSearchService), LanguageNames.VisualBasic), [Shared]>
+    <ExportLanguageService(GetType(INavigateToSearchService_RemoveInterfaceAboveAndRenameThisAfterInternalsVisibleToUsersUpdate), LanguageNames.VisualBasic), [Shared]>
     Friend Class VisualBasicNavigateToSearchService
         Inherits AbstractNavigateToSearchService
     End Class