Report in-flight tests and suggest --blame-crash when testhost crashes

src/Microsoft.TestPlatform.CommunicationUtilities/EventHandlers/TestRunEventsHandler.cs

@@ -15,7 +15,7 @@ namespace Microsoft.VisualStudio.TestPlatform.CommunicationUtilities.EventHandle
 /// <summary>
 /// The test run events handler.
 /// </summary>
-public class TestRunEventsHandler : IInternalTestRunEventsHandler
+public class TestRunEventsHandler : IInternalTestRunEventsHandler, ITestCaseLifecycleNotifier
 {
     private readonly ITestRequestHandler _requestHandler;
 
@@ -104,4 +104,12 @@ public bool AttachDebuggerToProcess(AttachDebuggerInfo attachDebuggerInfo)
         EqtTrace.Info("Sending AttachDebuggerToProcess on additional test process with pid: {0}", attachDebuggerInfo.ProcessId);
         return _requestHandler.AttachDebuggerToProcess(attachDebuggerInfo);
     }
+
+    /// <inheritdoc/>
+    void ITestCaseLifecycleNotifier.SendTestCaseStarting(TestCase testCase)
+        => _requestHandler.SendTestCaseStarting(testCase);
+
+    /// <inheritdoc/>
+    void ITestCaseLifecycleNotifier.SendTestCaseFinished(TestCase testCase)
+        => _requestHandler.SendTestCaseFinished(testCase);
 }

src/Microsoft.TestPlatform.CommunicationUtilities/InFlightTestTracker.cs

@@ -0,0 +1,198 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using System;
+using System.Collections.Concurrent;
+using System.Collections.Generic;
+
+using Microsoft.VisualStudio.TestPlatform.CommunicationUtilities.ObjectModel;
+
+namespace Microsoft.VisualStudio.TestPlatform.CommunicationUtilities;
+
+/// <summary>
+/// Tracks a set of in-flight test executions that share the same <see cref="Guid"/>.
+/// Uses inline slots to avoid queue allocation in the common case (unique Guid per test).
+/// All mutation and enumeration is guarded by a lock because the message-receive thread
+/// updates slots while the abort thread may read them concurrently via <see cref="GetAll"/>.
+/// </summary>
+internal sealed class InFlightTest
+{
+    private readonly object _lock = new();
+    public TestCaseStartingPayload Slot0;
+    public DateTimeOffset StartTime0;
+    public TestCaseStartingPayload? Slot1;
+    public DateTimeOffset StartTime1;
+    public TestCaseStartingPayload? Slot2;
+    public DateTimeOffset StartTime2;
+    public TestCaseStartingPayload? Slot3;
+    public DateTimeOffset StartTime3;
+    public Queue<(TestCaseStartingPayload Payload, DateTimeOffset StartTime)>? Overflow;
+
+    public InFlightTest(TestCaseStartingPayload payload, DateTimeOffset startTime)
+    {
+        Slot0 = payload;
+        StartTime0 = startTime;
+    }
+
+    /// <summary>
+    /// Adds another in-flight execution for the same Guid.
+    /// </summary>
+    public void Add(TestCaseStartingPayload payload, DateTimeOffset startTime)
+    {
+        lock (_lock)
+        {
+            if (Slot1 is null)
+            {
+                Slot1 = payload;
+                StartTime1 = startTime;
+            }
+            else if (Slot2 is null)
+            {
+                Slot2 = payload;
+                StartTime2 = startTime;
+            }
+            else if (Slot3 is null)
+            {
+                Slot3 = payload;
+                StartTime3 = startTime;
+            }
+            else
+            {
+                Overflow ??= new Queue<(TestCaseStartingPayload, DateTimeOffset)>();
+                Overflow.Enqueue((payload, startTime));
+            }
+        }
+    }
+
+    /// <summary>
+    /// Removes the oldest in-flight execution (FIFO). Returns true if there are still entries remaining.
+    /// </summary>
+    public bool RemoveOldest()
+    {
+        lock (_lock)
+        {
+            // Shift slots down
+            if (Slot1 is not null)
+            {
+                Slot0 = Slot1;
+                StartTime0 = StartTime1;
+                Slot1 = Slot2;
+                StartTime1 = StartTime2;
+                Slot2 = Slot3;
+                StartTime2 = StartTime3;
+                Slot3 = null;
+                StartTime3 = default;
+
+                // Refill Slot3 from overflow if available
+                if (Overflow is { Count: > 0 })
+                {
+                    var (payload, startTime) = Overflow.Dequeue();
+                    Slot3 = payload;
+                    StartTime3 = startTime;
+                }
+
+                return true;
+            }
+
+            // Slot0 was the only entry
+            return false;
+        }
+    }
+
+    /// <summary>
+    /// Returns a snapshot of all in-flight entries with their display name and start time.
+    /// </summary>
+    public IReadOnlyList<(string? DisplayName, DateTimeOffset StartTime)> GetAll()
+    {
+        lock (_lock)
+        {
+            var result = new List<(string?, DateTimeOffset)>();
+            result.Add((Slot0.DisplayName, StartTime0));
+
+            if (Slot1 is not null)
+            {
+                result.Add((Slot1.DisplayName, StartTime1));
+            }
+
+            if (Slot2 is not null)
+            {
+                result.Add((Slot2.DisplayName, StartTime2));
+            }
+
+            if (Slot3 is not null)
+            {
+                result.Add((Slot3.DisplayName, StartTime3));
+            }
+
+            if (Overflow is not null)
+            {
+                foreach (var (payload, startTime) in Overflow)
+                {
+                    result.Add((payload.DisplayName, startTime));
+                }
+            }
+
+            return result;
+        }
+    }
+}
+
+/// <summary>
+/// Thread-safe tracker for tests currently executing in a testhost.
+/// Used by vstest.console to report which tests were running when a testhost crashes.
+/// </summary>
+internal sealed class InFlightTestTracker
+{
+    private readonly ConcurrentDictionary<Guid, InFlightTest> _tests = new();
+
+    /// <summary>
+    /// Records that a test has started executing.
+    /// </summary>
+    public void TestStarting(TestCaseStartingPayload payload, DateTimeOffset startTime)
+    {
+        _tests.AddOrUpdate(
+            payload.Id,
+            _ => new InFlightTest(payload, startTime),
+            (_, existing) =>
+            {
+                existing.Add(payload, startTime);
+                return existing;
+            });
+    }
+
+    /// <summary>
+    /// Records that a test has finished executing. Removes the oldest execution for the given Guid.
+    /// </summary>
+    public void TestFinished(Guid testId)
+    {
+        if (_tests.TryGetValue(testId, out var inFlight))
+        {
+            if (!inFlight.RemoveOldest())
+            {
+                _tests.TryRemove(testId, out _);
+            }
+        }
+    }
+
+    /// <summary>
+    /// Gets all tests that are currently in-flight. Used when testhost crashes to report what was running.
+    /// </summary>
+    public IReadOnlyList<(string? DisplayName, DateTimeOffset StartTime)> GetInFlightTests()
+    {
+        var result = new List<(string?, DateTimeOffset)>();
+        foreach (var kvp in _tests)
+        {
+            foreach (var entry in kvp.Value.GetAll())
+            {
+                result.Add(entry);
+            }
+        }
+
+        return result;
+    }
+
+    /// <summary>
+    /// Returns true if there are any in-flight tests being tracked.
+    /// </summary>
+    public bool HasInFlightTests => !_tests.IsEmpty;
+}

src/Microsoft.TestPlatform.CommunicationUtilities/Interfaces/ITestCaseLifecycleNotifier.cs

@@ -0,0 +1,17 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using Microsoft.VisualStudio.TestPlatform.ObjectModel;
+
+namespace Microsoft.VisualStudio.TestPlatform.CommunicationUtilities.Interfaces;
+
+/// <summary>
+/// Provides lightweight test case lifecycle notifications for real-time in-flight tracking.
+/// Implemented by event handlers that can relay start/finish signals to the console.
+/// </summary>
+internal interface ITestCaseLifecycleNotifier
+{
+    void SendTestCaseStarting(TestCase testCase);
+
+    void SendTestCaseFinished(TestCase testCase);
+}

src/Microsoft.TestPlatform.CommunicationUtilities/Interfaces/ITestRequestHandler.cs

@@ -94,4 +94,18 @@ public interface ITestRequestHandler : IDisposable
     /// <param name="attachDebuggerInfo">Process ID and tfm of the process to which the debugger should be attached.</param>
     /// <returns><see langword="true"/> if the debugger was successfully attached to the requested process, <see langword="false"/> otherwise.</returns>
     bool AttachDebuggerToProcess(AttachDebuggerInfo attachDebuggerInfo);
+
+    /// <summary>
+    /// Sends a lightweight notification that a test case has started executing.
+    /// Used for real-time in-flight test tracking on the console side.
+    /// </summary>
+    /// <param name="testCase">The test case that started.</param>
+    void SendTestCaseStarting(TestCase testCase);
+
+    /// <summary>
+    /// Sends a lightweight notification that a test case has finished executing.
+    /// Used for real-time in-flight test tracking on the console side.
+    /// </summary>
+    /// <param name="testCase">The test case that finished.</param>
+    void SendTestCaseFinished(TestCase testCase);
 }

src/Microsoft.TestPlatform.CommunicationUtilities/Messages/MessageType.cs

@@ -111,6 +111,18 @@ public static class MessageType
     /// </summary>
     public const string TestRunStatsChange = "TestExecution.StatsChange";
 
+    /// <summary>
+    /// Lightweight notification that a test case has started executing.
+    /// Sent unbatched from testhost to console for real-time in-flight test tracking.
+    /// </summary>
+    public const string TestCaseStarting = "TestExecution.TestCaseStarting";
+
+    /// <summary>
+    /// Lightweight notification that a test case has finished executing.
+    /// Sent unbatched from testhost to console for real-time in-flight test tracking.
+    /// </summary>
+    public const string TestCaseFinished = "TestExecution.TestCaseFinished";
+
     /// <summary>
     /// The execution complete.
     /// </summary>

src/Microsoft.TestPlatform.CommunicationUtilities/Messages/TestCaseFinishedPayload.cs

@@ -0,0 +1,20 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using System;
+using System.Runtime.Serialization;
+
+namespace Microsoft.VisualStudio.TestPlatform.CommunicationUtilities.ObjectModel;
+
+/// <summary>
+/// Payload for the TestCaseFinished message, sent from testhost to console when a test completes execution.
+/// </summary>
+[DataContract]
+public class TestCaseFinishedPayload
+{
+    /// <summary>
+    /// Gets or sets the test case ID.
+    /// </summary>
+    [DataMember]
+    public Guid Id { get; set; }
+}

src/Microsoft.TestPlatform.CommunicationUtilities/Messages/TestCaseStartingPayload.cs

@@ -0,0 +1,26 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using System;
+using System.Runtime.Serialization;
+
+namespace Microsoft.VisualStudio.TestPlatform.CommunicationUtilities.ObjectModel;
+
+/// <summary>
+/// Payload for the TestCaseStarting message, sent from testhost to console when a test begins execution.
+/// </summary>
+[DataContract]
+public class TestCaseStartingPayload
+{
+    /// <summary>
+    /// Gets or sets the test case ID.
+    /// </summary>
+    [DataMember]
+    public Guid Id { get; set; }
+
+    /// <summary>
+    /// Gets or sets the display name of the test case.
+    /// </summary>
+    [DataMember]
+    public string? DisplayName { get; set; }
+}

src/Microsoft.TestPlatform.CommunicationUtilities/PublicAPI/PublicAPI.Unshipped.txt

@@ -1,5 +1,19 @@
 #nullable enable
 const Microsoft.VisualStudio.TestPlatform.CommunicationUtilities.ObjectModel.MessageType.TelemetryEventMessage = "TestPlatform.TelemetryEvent" -> string!
+const Microsoft.VisualStudio.TestPlatform.CommunicationUtilities.ObjectModel.MessageType.TestCaseFinished = "TestExecution.TestCaseFinished" -> string!
+const Microsoft.VisualStudio.TestPlatform.CommunicationUtilities.ObjectModel.MessageType.TestCaseStarting = "TestExecution.TestCaseStarting" -> string!
+Microsoft.VisualStudio.TestPlatform.CommunicationUtilities.Interfaces.ITestRequestHandler.SendTestCaseFinished(Microsoft.VisualStudio.TestPlatform.ObjectModel.TestCase! testCase) -> void
+Microsoft.VisualStudio.TestPlatform.CommunicationUtilities.Interfaces.ITestRequestHandler.SendTestCaseStarting(Microsoft.VisualStudio.TestPlatform.ObjectModel.TestCase! testCase) -> void
+Microsoft.VisualStudio.TestPlatform.CommunicationUtilities.ObjectModel.TestCaseFinishedPayload
+Microsoft.VisualStudio.TestPlatform.CommunicationUtilities.ObjectModel.TestCaseFinishedPayload.Id.get -> System.Guid
+Microsoft.VisualStudio.TestPlatform.CommunicationUtilities.ObjectModel.TestCaseFinishedPayload.Id.set -> void
+Microsoft.VisualStudio.TestPlatform.CommunicationUtilities.ObjectModel.TestCaseFinishedPayload.TestCaseFinishedPayload() -> void
+Microsoft.VisualStudio.TestPlatform.CommunicationUtilities.ObjectModel.TestCaseStartingPayload
+Microsoft.VisualStudio.TestPlatform.CommunicationUtilities.ObjectModel.TestCaseStartingPayload.DisplayName.get -> string?
+Microsoft.VisualStudio.TestPlatform.CommunicationUtilities.ObjectModel.TestCaseStartingPayload.DisplayName.set -> void
+Microsoft.VisualStudio.TestPlatform.CommunicationUtilities.ObjectModel.TestCaseStartingPayload.Id.get -> System.Guid
+Microsoft.VisualStudio.TestPlatform.CommunicationUtilities.ObjectModel.TestCaseStartingPayload.Id.set -> void
+Microsoft.VisualStudio.TestPlatform.CommunicationUtilities.ObjectModel.TestCaseStartingPayload.TestCaseStartingPayload() -> void
 ~static Microsoft.VisualStudio.TestPlatform.CommunicationUtilities.Resources.Resources.ConnectionTimeoutProcessDidNotStartErrorMessage.get -> string
 ~static Microsoft.VisualStudio.TestPlatform.CommunicationUtilities.Resources.Resources.ConnectionTimeoutProcessExitedErrorMessage.get -> string
 ~static Microsoft.VisualStudio.TestPlatform.CommunicationUtilities.Resources.Resources.ConnectionTimeoutWithDetailsErrorMessage.get -> string