Properly await calls to ensure exception handling works for sync and async scenarios (dotnet#81826)

Author: CyrusNajmabadi

src/LanguageServer/Protocol/Handler/AbstractRefreshQueue.cs

@@ -104,7 +104,7 @@ protected void EnqueueRefreshNotification(DocumentUri? documentUri)
         }
     }
 
-    private ValueTask FilterLspTrackedDocumentsAsync(
+    private async ValueTask FilterLspTrackedDocumentsAsync(
         LspWorkspaceManager lspWorkspaceManager,
         IClientLanguageServerManager notificationManager,
         ImmutableSegmentedList<DocumentUri?> documentUris,
@@ -117,7 +117,11 @@ private ValueTask FilterLspTrackedDocumentsAsync(
             {
                 try
                 {
-                    return notificationManager.SendRequestAsync(GetWorkspaceRefreshName(), cancellationToken);
+                    // Fire the notification and immediately return.  Refresh notifications are server-wide, and are not
+                    // associated with a particular project/document.  So once we've sent one, we can stop processing
+                    // entirely.
+                    await notificationManager.SendRequestAsync(GetWorkspaceRefreshName(), cancellationToken).ConfigureAwait(false);
+                    return;
                 }
                 catch (Exception ex) when (ex is ObjectDisposedException or ConnectionLostException)
                 {
@@ -128,7 +132,6 @@ private ValueTask FilterLspTrackedDocumentsAsync(
         }
 
         // LSP is already tracking all changed documents so we don't need to send a refresh request.
-        return ValueTask.CompletedTask;
     }
 
     public virtual void Dispose()

src/LanguageServer/Protocol/Handler/SourceGenerators/SourceGeneratorRefreshQueue.cs

@@ -120,27 +120,25 @@ await newProject.GetDependentVersionAsync(_disposalTokenSource.Token).ConfigureA
         }
     }
 
-    private ValueTask RefreshSourceGeneratedDocumentsAsync(
+    private async ValueTask RefreshSourceGeneratedDocumentsAsync(
         CancellationToken cancellationToken)
     {
         var hasOpenSourceGeneratedDocuments = _lspWorkspaceManager.GetTrackedLspText().Keys.Any(uri => uri.ParsedUri?.Scheme == SourceGeneratedDocumentUri.Scheme);
         if (!hasOpenSourceGeneratedDocuments)
         {
             // There are no opened source generated documents - we don't need to bother asking the client to refresh anything.
-            return ValueTask.CompletedTask;
+            return;
         }
 
         try
         {
-            return _notificationManager.SendNotificationAsync(RefreshSourceGeneratedDocumentName, cancellationToken);
+            await _notificationManager.SendNotificationAsync(RefreshSourceGeneratedDocumentName, cancellationToken).ConfigureAwait(false);
         }
         catch (Exception ex) when (ex is ObjectDisposedException or ConnectionLostException)
         {
             // It is entirely possible that we're shutting down and the connection is lost while we're trying to send a notification
             // as this runs outside of the guaranteed ordering in the queue. We can safely ignore this exception.
         }
-
-        return ValueTask.CompletedTask;
     }
 
     public void Dispose()