Unit tests for manager

src/Microsoft.TestPlatform.Common/Interfaces/Engine/IMultiTestRunFinalizationManager.cs

@@ -3,6 +3,7 @@
 
 using Microsoft.VisualStudio.TestPlatform.ObjectModel.Client;
 using System.Collections.Generic;
+using System.Collections.ObjectModel;
 using System.Threading;
 using System.Threading.Tasks;
 
@@ -14,11 +15,19 @@ namespace Microsoft.VisualStudio.TestPlatform.ObjectModel.Engine
     internal interface IMultiTestRunFinalizationManager
     {
         /// <summary>
-        /// Finalizes multi test run
+        /// Finalizes multi test run and provides results through handler
         /// </summary>
         /// <param name="attachments">Attachments</param>
         /// <param name="eventHandler">EventHandler for handling multi test run finalization events from Engine</param>
         /// <param name="cancellationToken">Cancellation token</param>
         Task FinalizeMultiTestRunAsync(ICollection<AttachmentSet> attachments, IMultiTestRunFinalizationEventsHandler eventHandler, CancellationToken cancellationToken);
+
+        /// <summary>
+        /// Finalizes multi test
+        /// </summary>
+        /// <param name="attachments">Attachments</param>
+        /// <param name="eventHandler">EventHandler for handling multi test run finalization events from Engine</param>
+        /// <param name="cancellationToken">Cancellation token</param>
+        Task<Collection<AttachmentSet>> FinalizeMultiTestRunAsync(ICollection<AttachmentSet> attachments, CancellationToken cancellationToken);
     }
 }

src/Microsoft.TestPlatform.CrossPlatEngine/DataCollection/ParallelDataCollectionEventsHandler.cs

@@ -4,6 +4,7 @@
 namespace Microsoft.VisualStudio.TestPlatform.CrossPlatEngine.DataCollection
 {
     using System.Collections.Generic;
+    using System.Collections.ObjectModel;
     using System.Threading;
     using Microsoft.VisualStudio.TestPlatform.CommunicationUtilities;
     using Microsoft.VisualStudio.TestPlatform.CommunicationUtilities.Interfaces;
@@ -58,13 +59,13 @@ public override void HandleTestRunComplete(
 
             if (parallelRunComplete)
             {
-                finalizationManager.FinalizeMultiTestRunAsync(runDataAggregator.RunContextAttachments, null, cancellationToken).Wait();
+                Collection<AttachmentSet> attachments = finalizationManager.FinalizeMultiTestRunAsync(runDataAggregator.RunContextAttachments, cancellationToken).Result;
 
                 var completedArgs = new TestRunCompleteEventArgs(this.runDataAggregator.GetAggregatedRunStats(),
                     this.runDataAggregator.IsCanceled,
                     this.runDataAggregator.IsAborted,
                     this.runDataAggregator.GetAggregatedException(),
-                    this.runDataAggregator.RunContextAttachments,
+                    attachments,
                     this.runDataAggregator.ElapsedTime);
 
                 // Add Metrics from Test Host

src/Microsoft.TestPlatform.CrossPlatEngine/MultiTestRunFinalization/MultiTestRunFinalizationManager.cs

@@ -32,19 +32,25 @@ public MultiTestRunFinalizationManager(ITestPlatformEventSource testPlatformEven
             this.dataCollectorAttachmentsHandlers = dataCollectorAttachmentsHandlers ?? throw new ArgumentNullException(nameof(dataCollectorAttachmentsHandlers));
         }
 
-        /// <summary>
-        /// Finalizes multi test run
-        /// </summary>
-        /// <param name="attachments">Attachments</param>
-        /// <param name="eventHandler">EventHandler for handling multi test run finalization events from Engine</param>
-        /// <param name="cancellationToken">Cancellation token</param>
+        /// <inheritdoc/>
         public async Task FinalizeMultiTestRunAsync(ICollection<AttachmentSet> attachments, IMultiTestRunFinalizationEventsHandler eventHandler, CancellationToken cancellationToken)
+        {
+            await InternalFinalizeMultiTestRunAsync(new Collection<AttachmentSet>(attachments.ToList()), eventHandler, cancellationToken);
+        }
+
+        /// <inheritdoc/>
+        public Task<Collection<AttachmentSet>> FinalizeMultiTestRunAsync(ICollection<AttachmentSet> attachments, CancellationToken cancellationToken)
+        {
+            return InternalFinalizeMultiTestRunAsync(new Collection<AttachmentSet>(attachments.ToList()), null, cancellationToken);
+        }
+
+        private async Task<Collection<AttachmentSet>> InternalFinalizeMultiTestRunAsync(Collection<AttachmentSet> attachments, IMultiTestRunFinalizationEventsHandler eventHandler, CancellationToken cancellationToken)
         {
             try
             {
-                cancellationToken.ThrowIfCancellationRequested();
+                testPlatformEventSource.MultiTestRunFinalizationStart(attachments?.Count ?? 0);
 
-                testPlatformEventSource.MultiTestRunFinalizationStart(attachments.Count);
+                cancellationToken.ThrowIfCancellationRequested();                
 
                 var taskCompletionSource = new TaskCompletionSource<object>();
                 cancellationToken.Register(() =>
@@ -54,21 +60,26 @@ public async Task FinalizeMultiTestRunAsync(ICollection<AttachmentSet> attachmen
 
                 Task task = Task.Run(() =>
                 {
-                    HandleAttachements(attachments, cancellationToken);                    
+                    HandleAttachements(attachments, cancellationToken);
                 });
 
                 var completedTask = await Task.WhenAny(task, taskCompletionSource.Task);
 
                 if (completedTask == task)
                 {
+                    await task;
                     eventHandler?.HandleMultiTestRunFinalizationComplete(attachments);
                     testPlatformEventSource.MultiTestRunFinalizationStop(attachments.Count);
+                    return attachments;
                 }
                 else
                 {
+                    eventHandler?.HandleLogMessage(ObjectModel.Logging.TestMessageLevel.Informational, "Finalization was cancelled.");
                     eventHandler?.HandleMultiTestRunFinalizationComplete(null);
-                    testPlatformEventSource.MultiTestRunFinalizationStop(0);
+                    testPlatformEventSource.MultiTestRunFinalizationStop(0);                    
                 }
+
+                return null;
             }
             catch (Exception e)
             {
@@ -77,6 +88,7 @@ public async Task FinalizeMultiTestRunAsync(ICollection<AttachmentSet> attachmen
                 eventHandler?.HandleLogMessage(ObjectModel.Logging.TestMessageLevel.Error, e.Message);
                 eventHandler?.HandleMultiTestRunFinalizationComplete(null);
                 testPlatformEventSource.MultiTestRunFinalizationStop(0);
+                return null;
             }
         }