Merge pull request #42966 from jaredpar/flaky

Fix EditorFeatures2 flakiness

src/EditorFeatures/TestUtilities/TestExtensionErrorHandler.cs

@@ -14,10 +14,13 @@
 namespace Microsoft.CodeAnalysis.Editor.UnitTests
 {
     [Export(typeof(IExtensionErrorHandler))]
-    internal class TestExtensionErrorHandler : IExtensionErrorHandler
+    [Export(typeof(ITestErrorHandler))]
+    internal class TestExtensionErrorHandler : IExtensionErrorHandler, ITestErrorHandler
     {
         private ImmutableList<Exception> _exceptions = ImmutableList<Exception>.Empty;
 
+        public ImmutableList<Exception> Exceptions => _exceptions;
+
         [ImportingConstructor]
         [Obsolete(MefConstruction.ImportingConstructorMessage, error: true)]
         public TestExtensionErrorHandler()
@@ -27,12 +30,31 @@ public TestExtensionErrorHandler()
         public void HandleError(object sender, Exception exception)
         {
             // Work around bug that is fixed in https://devdiv.visualstudio.com/DevDiv/_git/VS-Platform/pullrequest/209513
-            if (exception is NullReferenceException && exception.StackTrace.Contains("SpanTrackingWpfToolTipPresenter"))
+            if (exception is NullReferenceException &&
+                exception.StackTrace.Contains("SpanTrackingWpfToolTipPresenter"))
+            {
+                return;
+            }
+
+            // Work around for https://github.com/dotnet/roslyn/issues/42982
+            if (exception is NullReferenceException &&
+                exception.StackTrace.Contains("Microsoft.CodeAnalysis.Completion.Providers.AbstractEmbeddedLanguageCompletionProvider.GetLanguageProviders"))
+            {
+                return;
+            }
+
+            // Work around for https://devdiv.visualstudio.com/DevDiv/_workitems/edit/1091056
+            if (exception is InvalidOperationException &&
+                exception.StackTrace.Contains("Microsoft.VisualStudio.Language.Intellisense.AsyncCompletion.Implementation.CompletionTelemetryHost"))
             {
                 return;
             }
 
-            ExceptionUtilities.FailFast(exception);
+            // This exception is unexpected and as such we want the containing test case to
+            // fail. Unfortuntately throwing an exception here is not going to help because
+            // the editor is going to catch and swallow it. Store it here and wait for the 
+            // containing workspace to notice it and throw.
+            _exceptions = _exceptions.Add(exception);
         }
     }
 }

src/Workspaces/CoreTestUtilities/ITestErrorHandler.cs

+// 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.
+
+#nullable enable
+
+using System;
+using System.Collections.Immutable;
+
+namespace Microsoft.CodeAnalysis.Test.Utilities
+{
+    public interface ITestErrorHandler
+    {
+        /// <summary>
+        /// Records unexpected exceptions thrown during test executino that can't be immediately
+        /// reported.
+        /// </summary>
+        ImmutableList<Exception> Exceptions { get; }
+    }
+}

src/Workspaces/CoreTestUtilities/MEF/UseExportProviderAttribute.cs

@@ -133,6 +133,15 @@ public override void After(MethodInfo methodUnderTest)
                     {
                         synchronizationContext.ThrowIfSwitchOccurred();
                     }
+
+                    foreach (var testErrorHandler in exportProvider.GetExportedValues<ITestErrorHandler>())
+                    {
+                        var exceptions = testErrorHandler.Exceptions;
+                        if (exceptions.Count > 0)
+                        {
+                            throw new AggregateException("Tests threw unexpected exceptions", exceptions);
+                        }
+                    }
                 }
             }
             finally