Change navigation helpers to operate in two steps.

src/EditorFeatures/Core.Wpf/Interactive/InteractiveDocumentNavigationService.cs

@@ -37,19 +37,19 @@ public Task<bool> CanNavigateToLineAndOffsetAsync(Workspace workspace, DocumentI
         public Task<bool> CanNavigateToPositionAsync(Workspace workspace, DocumentId documentId, int position, int virtualSpace, CancellationToken cancellationToken)
             => SpecializedTasks.False;
 
-        public async Task<bool> TryNavigateToSpanAsync(Workspace workspace, DocumentId documentId, TextSpan textSpan, NavigationOptions options, bool allowInvalidSpan, CancellationToken cancellationToken)
+        public async Task<INavigableLocation?> GetLocationForSpanAsync(Workspace workspace, DocumentId documentId, TextSpan textSpan, NavigationOptions options, bool allowInvalidSpan, CancellationToken cancellationToken)
         {
             await _threadingContext.JoinableTaskFactory.SwitchToMainThreadAsync(cancellationToken);
             if (workspace is not InteractiveWindowWorkspace interactiveWorkspace)
             {
                 Debug.Fail("InteractiveDocumentNavigationService called with incorrect workspace!");
-                return false;
+                return null;
             }
 
             if (interactiveWorkspace.Window is null)
             {
                 Debug.Fail("We are trying to navigate with a workspace that doesn't have a window!");
-                return false;
+                return null;
             }
 
             var textView = interactiveWorkspace.Window.TextView;
@@ -58,35 +58,40 @@ public async Task<bool> TryNavigateToSpanAsync(Workspace workspace, DocumentId d
             var textSnapshot = document?.GetTextSynchronously(cancellationToken).FindCorrespondingEditorTextSnapshot();
             if (textSnapshot == null)
             {
-                return false;
+                return null;
             }
 
             var snapshotSpan = new SnapshotSpan(textSnapshot, textSpan.Start, textSpan.Length);
             var virtualSnapshotSpan = new VirtualSnapshotSpan(snapshotSpan);
 
             if (!textView.TryGetSurfaceBufferSpan(virtualSnapshotSpan, out var surfaceBufferSpan))
             {
-                return false;
+                return null;
             }
 
-            textView.Selection.Select(surfaceBufferSpan.Start, surfaceBufferSpan.End);
-            textView.ViewScroller.EnsureSpanVisible(surfaceBufferSpan.SnapshotSpan, EnsureSpanVisibleOptions.AlwaysCenter);
+            return new NavigableLocation(async cancellationToken =>
+            {
+                await _threadingContext.JoinableTaskFactory.SwitchToMainThreadAsync(cancellationToken);
+
+                textView.Selection.Select(surfaceBufferSpan.Start, surfaceBufferSpan.End);
+                textView.ViewScroller.EnsureSpanVisible(surfaceBufferSpan.SnapshotSpan, EnsureSpanVisibleOptions.AlwaysCenter);
 
-            // Moving the caret must be the last operation involving surfaceBufferSpan because 
-            // it might update the version number of textView.TextSnapshot (VB does line commit
-            // when the caret leaves a line which might cause pretty listing), which must be 
-            // equal to surfaceBufferSpan.SnapshotSpan.Snapshot's version number.
-            textView.Caret.MoveTo(surfaceBufferSpan.Start);
+                // Moving the caret must be the last operation involving surfaceBufferSpan because 
+                // it might update the version number of textView.TextSnapshot (VB does line commit
+                // when the caret leaves a line which might cause pretty listing), which must be 
+                // equal to surfaceBufferSpan.SnapshotSpan.Snapshot's version number.
+                textView.Caret.MoveTo(surfaceBufferSpan.Start);
 
-            textView.VisualElement.Focus();
+                textView.VisualElement.Focus();
 
-            return true;
+                return true;
+            });
         }
 
-        public Task<bool> TryNavigateToLineAndOffsetAsync(Workspace workspace, DocumentId documentId, int lineNumber, int offset, NavigationOptions options, CancellationToken cancellationToken)
+        public Task<INavigableLocation?> GetLocationForLineAndOffsetAsync(Workspace workspace, DocumentId documentId, int lineNumber, int offset, NavigationOptions options, CancellationToken cancellationToken)
             => throw new NotSupportedException();
 
-        public Task<bool> TryNavigateToPositionAsync(Workspace workspace, DocumentId documentId, int position, int virtualSpace, NavigationOptions options, CancellationToken cancellationToken)
+        public Task<INavigableLocation?> GetLocationForPositionAsync(Workspace workspace, DocumentId documentId, int position, int virtualSpace, NavigationOptions options, CancellationToken cancellationToken)
             => throw new NotSupportedException();
     }
 }

src/EditorFeatures/TestUtilities2/Utilities/GoToHelpers/MockDocumentNavigationService.vb

@@ -40,33 +40,33 @@ Namespace Microsoft.CodeAnalysis.Editor.UnitTests.Utilities.GoToHelpers
             Return If(_canNavigateToSpan, SpecializedTasks.True, SpecializedTasks.False)
         End Function
 
-        Public Function TryNavigateToLineAndOffsetAsync(workspace As Workspace, documentId As DocumentId, lineNumber As Integer, offset As Integer, options As NavigationOptions, cancellationToken As CancellationToken) As Task(Of Boolean) Implements IDocumentNavigationService.TryNavigateToLineAndOffsetAsync
+        Public Function GetLocationForLineAndOffsetAsync(workspace As Workspace, documentId As DocumentId, lineNumber As Integer, offset As Integer, options As NavigationOptions, cancellationToken As CancellationToken) As Task(Of INavigableLocation) Implements IDocumentNavigationService.GetLocationForLineAndOffsetAsync
             _triedNavigationToLineAndOffset = True
             _documentId = documentId
             _options = options
             _line = lineNumber
             _offset = offset
 
-            Return If(_canNavigateToLineAndOffset, SpecializedTasks.True, SpecializedTasks.False)
+            Return NavigableLocation.TestAccessor.Create(_canNavigateToLineAndOffset)
         End Function
 
-        Public Function TryNavigateToPositionAsync(workspace As Workspace, documentId As DocumentId, position As Integer, virtualSpace As Integer, options As NavigationOptions, cancellationToken As CancellationToken) As Task(Of Boolean) Implements IDocumentNavigationService.TryNavigateToPositionAsync
+        Public Function GetLocationForPositionAsync(workspace As Workspace, documentId As DocumentId, position As Integer, virtualSpace As Integer, options As NavigationOptions, cancellationToken As CancellationToken) As Task(Of INavigableLocation) Implements IDocumentNavigationService.GetLocationForPositionAsync
             _triedNavigationToPosition = True
             _documentId = documentId
             _options = options
             _position = position
             _positionVirtualSpace = virtualSpace
 
-            Return If(_canNavigateToPosition, SpecializedTasks.True, SpecializedTasks.False)
+            Return NavigableLocation.TestAccessor.Create(_canNavigateToPosition)
         End Function
 
-        Public Function TryNavigateToSpanAsync(workspace As Workspace, documentId As DocumentId, textSpan As TextSpan, options As NavigationOptions, allowInvalidSpan As Boolean, cancellationToken As CancellationToken) As Task(Of Boolean) Implements IDocumentNavigationService.TryNavigateToSpanAsync
+        Public Function GetLocationForSpanAsync(workspace As Workspace, documentId As DocumentId, textSpan As TextSpan, options As NavigationOptions, allowInvalidSpan As Boolean, cancellationToken As CancellationToken) As Task(Of INavigableLocation) Implements IDocumentNavigationService.GetLocationForSpanAsync
             _triedNavigationToSpan = True
             _documentId = documentId
             _options = options
             _span = textSpan
 
-            Return If(_canNavigateToSpan, SpecializedTasks.True, SpecializedTasks.False)
+            Return NavigableLocation.TestAccessor.Create(_canNavigateToSpan)
         End Function
     End Class
 End Namespace

src/EditorFeatures/TestUtilities2/Utilities/MockDocumentNavigationServiceProvider.vb

@@ -70,30 +70,30 @@ Namespace Microsoft.CodeAnalysis.Editor.UnitTests.Utilities
                 Return If(CanNavigateToSpanReturnValue, SpecializedTasks.True, SpecializedTasks.False)
             End Function
 
-            Public Function TryNavigateToLineAndOffsetAsync(workspace As Workspace, documentId As DocumentId, lineNumber As Integer, offset As Integer, options As NavigationOptions, cancellationToken As CancellationToken) As Task(Of Boolean) Implements IDocumentNavigationService.TryNavigateToLineAndOffsetAsync
+            Public Function GetLocationForLineAndOffsetAsync(workspace As Workspace, documentId As DocumentId, lineNumber As Integer, offset As Integer, options As NavigationOptions, cancellationToken As CancellationToken) As Task(Of INavigableLocation) Implements IDocumentNavigationService.GetLocationForLineAndOffsetAsync
                 Me.ProvidedDocumentId = documentId
                 Me.ProvidedLineNumber = lineNumber
                 Me.ProvidedOffset = offset
                 Me.ProvidedOptions = options
 
-                Return If(TryNavigateToLineAndOffsetReturnValue, SpecializedTasks.True, SpecializedTasks.False)
+                Return NavigableLocation.TestAccessor.Create(TryNavigateToLineAndOffsetReturnValue)
             End Function
 
-            Public Function TryNavigateToPositionAsync(workspace As Workspace, documentId As DocumentId, position As Integer, virtualSpace As Integer, options As NavigationOptions, cancellationToken As CancellationToken) As Task(Of Boolean) Implements IDocumentNavigationService.TryNavigateToPositionAsync
+            Public Function GetLocationForPositionAsync(workspace As Workspace, documentId As DocumentId, position As Integer, virtualSpace As Integer, options As NavigationOptions, cancellationToken As CancellationToken) As Task(Of INavigableLocation) Implements IDocumentNavigationService.GetLocationForPositionAsync
                 Me.ProvidedDocumentId = documentId
                 Me.ProvidedPosition = position
                 Me.ProvidedVirtualSpace = virtualSpace
                 Me.ProvidedOptions = options
 
-                Return If(TryNavigateToPositionReturnValue, SpecializedTasks.True, SpecializedTasks.False)
+                Return NavigableLocation.TestAccessor.Create(TryNavigateToPositionReturnValue)
             End Function
 
-            Public Function TryNavigateToSpanAsync(workspace As Workspace, documentId As DocumentId, textSpan As TextSpan, options As NavigationOptions, allowInvalidSpans As Boolean, cancellationToken As CancellationToken) As Task(Of Boolean) Implements IDocumentNavigationService.TryNavigateToSpanAsync
+            Public Function GetLocationForSpanAsync(workspace As Workspace, documentId As DocumentId, textSpan As TextSpan, options As NavigationOptions, allowInvalidSpans As Boolean, cancellationToken As CancellationToken) As Task(Of INavigableLocation) Implements IDocumentNavigationService.GetLocationForSpanAsync
                 Me.ProvidedDocumentId = documentId
                 Me.ProvidedTextSpan = textSpan
                 Me.ProvidedOptions = options
 
-                Return If(TryNavigateToSpanReturnValue, SpecializedTasks.True, SpecializedTasks.False)
+                Return NavigableLocation.TestAccessor.Create(TryNavigateToSpanReturnValue)
             End Function
         End Class
     End Class

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

@@ -38,7 +38,6 @@ public bool TryNavigateToPosition(Workspace workspace, DocumentId documentId, in
             return _threadingProvider.Service.Run(() => obj.TryNavigateToPositionAsync(workspace, documentId, position, virtualSpace, NavigationOptions.Default, cancellationToken));
         }
 
-        /// <inheritdoc cref="IDocumentNavigationService.TryNavigateToPositionAsync"/>
         public bool TryNavigateToPosition(Workspace workspace, DocumentId documentId, int position, int virtualSpace, CancellationToken cancellationToken)
         {
             var obj = _underlyingObject;

src/Features/Core/Portable/Navigation/DefaultDocumentNavigationService.cs

@@ -20,13 +20,13 @@ public Task<bool> CanNavigateToLineAndOffsetAsync(Workspace workspace, DocumentI
         public Task<bool> CanNavigateToPositionAsync(Workspace workspace, DocumentId documentId, int position, int virtualSpace, CancellationToken cancellationToken)
             => SpecializedTasks.False;
 
-        public Task<bool> TryNavigateToSpanAsync(Workspace workspace, DocumentId documentId, TextSpan textSpan, NavigationOptions options, bool allowInvalidSpan, CancellationToken cancellationToken)
-            => SpecializedTasks.False;
+        public Task<INavigableLocation?> GetLocationForSpanAsync(Workspace workspace, DocumentId documentId, TextSpan textSpan, NavigationOptions options, bool allowInvalidSpan, CancellationToken cancellationToken)
+            => SpecializedTasks.Null<INavigableLocation>();
 
-        public Task<bool> TryNavigateToLineAndOffsetAsync(Workspace workspace, DocumentId documentId, int lineNumber, int offset, NavigationOptions options, CancellationToken cancellationToken)
-            => SpecializedTasks.False;
+        public Task<INavigableLocation?> GetLocationForLineAndOffsetAsync(Workspace workspace, DocumentId documentId, int lineNumber, int offset, NavigationOptions options, CancellationToken cancellationToken)
+            => SpecializedTasks.Null<INavigableLocation>();
 
-        public Task<bool> TryNavigateToPositionAsync(Workspace workspace, DocumentId documentId, int position, int virtualSpace, NavigationOptions options, CancellationToken cancellationToken)
-            => SpecializedTasks.False;
+        public Task<INavigableLocation?> GetLocationForPositionAsync(Workspace workspace, DocumentId documentId, int position, int virtualSpace, NavigationOptions options, CancellationToken cancellationToken)
+            => SpecializedTasks.Null<INavigableLocation>();
     }
 }

src/Features/Core/Portable/Navigation/IDocumentNavigationService.cs

@@ -27,20 +27,9 @@ internal interface IDocumentNavigationService : IWorkspaceService
         /// </summary>
         Task<bool> CanNavigateToPositionAsync(Workspace workspace, DocumentId documentId, int position, int virtualSpace, CancellationToken cancellationToken);
 
-        /// <summary>
-        /// Navigates to the given position in the specified document, opening it if necessary.
-        /// </summary>
-        Task<bool> TryNavigateToSpanAsync(Workspace workspace, DocumentId documentId, TextSpan textSpan, NavigationOptions options, bool allowInvalidSpan, CancellationToken cancellationToken);
-
-        /// <summary>
-        /// Navigates to the given line/offset in the specified document, opening it if necessary.
-        /// </summary>
-        Task<bool> TryNavigateToLineAndOffsetAsync(Workspace workspace, DocumentId documentId, int lineNumber, int offset, NavigationOptions options, CancellationToken cancellationToken);
-
-        /// <summary>
-        /// Navigates to the given virtual position in the specified document, opening it if necessary.
-        /// </summary>
-        Task<bool> TryNavigateToPositionAsync(Workspace workspace, DocumentId documentId, int position, int virtualSpace, NavigationOptions options, CancellationToken cancellationToken);
+        Task<INavigableLocation?> GetLocationForSpanAsync(Workspace workspace, DocumentId documentId, TextSpan textSpan, NavigationOptions options, bool allowInvalidSpan, CancellationToken cancellationToken);
+        Task<INavigableLocation?> GetLocationForLineAndOffsetAsync(Workspace workspace, DocumentId documentId, int lineNumber, int offset, NavigationOptions options, CancellationToken cancellationToken);
+        Task<INavigableLocation?> GetLocationForPositionAsync(Workspace workspace, DocumentId documentId, int position, int virtualSpace, NavigationOptions options, CancellationToken cancellationToken);
     }
 
     internal static class IDocumentNavigationServiceExtensions
@@ -59,5 +48,38 @@ public static Task<bool> TryNavigateToLineAndOffsetAsync(this IDocumentNavigatio
 
         public static Task<bool> TryNavigateToPositionAsync(this IDocumentNavigationService service, Workspace workspace, DocumentId documentId, int position, CancellationToken cancellationToken)
             => service.TryNavigateToPositionAsync(workspace, documentId, position, virtualSpace: 0, NavigationOptions.Default, cancellationToken);
+
+        /// <summary>
+        /// Navigates to the given position in the specified document, opening it if necessary.
+        /// </summary>
+        public static async Task<bool> TryNavigateToSpanAsync(this IDocumentNavigationService service, Workspace workspace, DocumentId documentId, TextSpan textSpan, NavigationOptions options, bool allowInvalidSpan, CancellationToken cancellationToken)
+        {
+            var location = await service.GetLocationForSpanAsync(
+                workspace, documentId, textSpan, options, allowInvalidSpan, cancellationToken).ConfigureAwait(false);
+            return location != null &&
+                await location.NavigateToAsync(cancellationToken).ConfigureAwait(false);
+        }
+
+        /// <summary>
+        /// Navigates to the given line/offset in the specified document, opening it if necessary.
+        /// </summary>
+        public static async Task<bool> TryNavigateToLineAndOffsetAsync(this IDocumentNavigationService service, Workspace workspace, DocumentId documentId, int lineNumber, int offset, NavigationOptions options, CancellationToken cancellationToken)
+        {
+            var location = await service.GetLocationForLineAndOffsetAsync(
+                workspace, documentId, lineNumber, offset, options, cancellationToken).ConfigureAwait(false);
+            return location != null &&
+                await location.NavigateToAsync(cancellationToken).ConfigureAwait(false);
+        }
+
+        /// <summary>
+        /// Navigates to the given virtual position in the specified document, opening it if necessary.
+        /// </summary>
+        public static async Task<bool> TryNavigateToPositionAsync(this IDocumentNavigationService service, Workspace workspace, DocumentId documentId, int position, int virtualSpace, NavigationOptions options, CancellationToken cancellationToken)
+        {
+            var location = await service.GetLocationForPositionAsync(
+                workspace, documentId, position, virtualSpace, options, cancellationToken).ConfigureAwait(false);
+            return location != null &&
+                await location.NavigateToAsync(cancellationToken).ConfigureAwait(false);
+        }
     }
 }

src/Features/Core/Portable/Navigation/INavigableDocumentLocation.cs

@@ -0,0 +1,44 @@
+// 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.Threading;
+using System.Threading.Tasks;
+using Roslyn.Utilities;
+
+namespace Microsoft.CodeAnalysis.Navigation
+{
+    internal interface INavigableLocation
+    {
+        /// <summary>
+        /// Navigates to a location opening or presenting it in a UI if necessary.  This work must happen quickly. Any
+        /// expensive async work must be done by whatever component creates this value. This method is async only to
+        /// allow final clients to call this from a non-UI thread while allowing the navigation to jump to the UI
+        /// thread.
+        /// </summary>
+        Task<bool> NavigateToAsync(CancellationToken cancelletionToken);
+    }
+
+    internal class NavigableLocation : INavigableLocation
+    {
+        private readonly Func<CancellationToken, Task<bool>> _callback;
+
+        public NavigableLocation(Func<CancellationToken, Task<bool>> callback)
+            => _callback = callback;
+
+        public Task<bool> NavigateToAsync(CancellationToken cancellationToken)
+            => _callback(cancellationToken);
+
+        public static class TestAccessor
+        {
+#pragma warning disable VSTHRD200 // Use "Async" suffix for async methods
+            public static Task<INavigableLocation?> Create(bool value)
+#pragma warning restore VSTHRD200 // Use "Async" suffix for async methods
+            {
+                return Task.FromResult<INavigableLocation?>(
+                    new NavigableLocation(c => value ? SpecializedTasks.True : SpecializedTasks.False));
+            }
+        }
+    }
+}