Don't use batching work queue in ProjectConfigurationStateSynchronizer

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/ProjectConfigurationStateSynchronizer.TestAccessor.cs

@@ -1,7 +1,10 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT license. See License.txt in the project root for license information.
 
+using System.Collections.Generic;
+using System.Threading;
 using System.Threading.Tasks;
+using Microsoft.VisualStudio.Threading;
 
 namespace Microsoft.AspNetCore.Razor.LanguageServer;
 
@@ -11,7 +14,37 @@ internal partial class ProjectConfigurationStateSynchronizer
 
     internal sealed class TestAccessor(ProjectConfigurationStateSynchronizer instance)
     {
-        public Task WaitUntilCurrentBatchCompletesAsync()
-            => instance._workQueue.WaitUntilCurrentBatchCompletesAsync();
+        public Task WaitForProjectUpdatesToDrainAsync(CancellationToken cancellationToken)
+        {
+            return Task.Run(async () =>
+            {
+                while (UpdatesRemaining() > 0)
+                {
+                    await Task.Yield();
+                }
+
+                int UpdatesRemaining()
+                {
+                    lock (instance._projectUpdates)
+                    {
+                        var count = instance._projectUpdates.Count;
+
+                        if (count > 0)
+                        {
+                            foreach (var (_, updateItem) in instance._projectUpdates)
+                            {
+                                if (updateItem.Task is null || updateItem.Task.IsCompleted)
+                                {
+                                    count--;
+                                }
+                            }
+                        }
+
+                        return count;
+                    }
+                }
+            },
+            cancellationToken);
+        }
     }
 }