A few further improvements to DTB error telemetry logging

src/Microsoft.VisualStudio.ProjectSystem.Managed.VS/ProjectSystem/VS/DesignTimeBuilds/DesignTimeBuildLoggerProvider.cs

@@ -54,25 +54,28 @@ private sealed class DesignTimeTelemetryLogger(ITelemetryService telemetryServic
         /// <remarks>
         /// The initial capacity here is based on an empty .NET Console App's DTB, which has
         /// around 120 targets, and aims to avoid resizing the dictionary during the build.
+        ///
+        /// Targets can run concurrently, so use of this collection must be protected by a lock.
         /// </remarks>
         private readonly Dictionary<int, TargetRecord> _targetRecordById = new(capacity: 140);
 
         /// <summary>
-        /// The names of any targets that reported errors. Names may be hashed.
-        /// May be empty even when errors exist, as not all errors come from a target.
+        /// Data about any errors that occurred during the build. Note that design-time build
+        /// targets are supposed to be authored to respect ContinueOnError, so errors might
+        /// not fail the build. However it's still useful to know which targets reported errors.
+        /// 
+        /// Similarly, this collection may be empty even when the build fails.
         /// </summary>
-        private List<string>? _errorTargets;
+        /// <remarks>
+        /// Targets can run concurrently, so use of this collection must be protected by a lock.
+        /// </remarks>
+        private readonly List<ErrorData> _errors = [];
 
         /// <summary>
         /// Whether the build succeeded.
         /// </summary>
         private bool? _succeeded;
 
-        /// <summary>
-        /// The number of errors reported during the build.
-        /// </summary>
-        private int _errorCount;
-
         LoggerVerbosity ILogger.Verbosity { get; set; }
 
         string? ILogger.Parameters { get; set; }
@@ -93,7 +96,10 @@ void OnTargetStarted(object sender, TargetStartedEventArgs e)
                         e.TargetFile,
                         file => ProjectFileClassifier.IsShippedByMicrosoft(e.TargetFile));
 
-                    _targetRecordById[id] = new TargetRecord(e.TargetName, IsMicrosoft: isMicrosoft, e.Timestamp);
+                    lock (_targetRecordById)
+                    {
+                        _targetRecordById[id] = new TargetRecord(e.TargetName, IsMicrosoft: isMicrosoft, e.Timestamp);
+                    }
                 }
             }
 
@@ -107,12 +113,16 @@ void OnTargetFinished(object sender, TargetFinishedEventArgs e)
 
             void OnErrorRaised(object sender, BuildErrorEventArgs e)
             {
-                _errorCount++;
+                string? targetName = null;
 
                 if (TryGetTargetRecord(e.BuildEventContext, out TargetRecord? record))
                 {
-                    _errorTargets ??= [];
-                    _errorTargets.Add(GetHashedTargetName(record));
+                    targetName = GetHashedTargetName(record);
+                }
+
+                lock (_errors)
+                {
+                    _errors.Add(new(targetName, e.Code));
                 }
             }
 
@@ -123,9 +133,12 @@ void OnBuildFinished(object sender, BuildFinishedEventArgs e)
 
             bool TryGetTargetRecord(BuildEventContext? context, [NotNullWhen(returnValue: true)] out TargetRecord? record)
             {
-                if (context is { TargetId: int id } && _targetRecordById.TryGetValue(id, out record))
+                lock (_targetRecordById)
                 {
-                    return true;
+                    if (context is { TargetId: int id } && _targetRecordById.TryGetValue(id, out record))
+                    {
+                        return true;
+                    }
                 }
 
                 record = null;
@@ -141,29 +154,40 @@ void ILogger.Shutdown()
 
             void SendTelemetry()
             {
-                // Filter out very fast targets (to reduce the cost of ordering) then take the top ten by elapsed time.
-                // Note that targets can run multiple times, so the same target may appear more than once in the results.
-                object[][] targetDurations = _targetRecordById.Values
-                    .Where(static record => record.Elapsed > new TimeSpan(ticks: 5 * TimeSpan.TicksPerMillisecond))
-                    .OrderByDescending(record => record.Elapsed)
-                    .Take(10)
-                    .Select(record => new object[] { GetHashedTargetName(record), record.Elapsed.Milliseconds })
-                    .ToArray();
+                object[][] targetDurations;
+                ErrorData[] errors;
+
+                lock (_targetRecordById)
+                {
+                    // Filter out very fast targets (to reduce the cost of ordering) then take the top ten by elapsed time.
+                    // Note that targets can run multiple times, so the same target may appear more than once in the results.
+                    targetDurations = _targetRecordById.Values
+                        .Where(static record => record.Elapsed > new TimeSpan(ticks: 5 * TimeSpan.TicksPerMillisecond))
+                        .OrderByDescending(record => record.Elapsed)
+                        .Take(10)
+                        .Select(record => new object[] { GetHashedTargetName(record), record.Elapsed.Milliseconds })
+                        .ToArray();
+
+                    errors = _errors.ToArray();
+                }
 
                 telemetryService.PostProperties(
                     TelemetryEventName.DesignTimeBuildComplete,
                     [
                         (TelemetryPropertyName.DesignTimeBuildComplete.Succeeded, _succeeded),
                         (TelemetryPropertyName.DesignTimeBuildComplete.Targets, new ComplexPropertyValue(targetDurations)),
-                        (TelemetryPropertyName.DesignTimeBuildComplete.ErrorCount, _errorCount),
-                        (TelemetryPropertyName.DesignTimeBuildComplete.ErrorTargets, _errorTargets),
+                        (TelemetryPropertyName.DesignTimeBuildComplete.ErrorCount, errors.Length),
+                        (TelemetryPropertyName.DesignTimeBuildComplete.Errors, new ComplexPropertyValue(errors)),
                     ]);
             }
 
             void ReportBuildErrors()
             {
-                if (_errorCount is 0)
+                if (_succeeded is not false)
                 {
+                    // Only report a failure if the build failed. Specific targets can have
+                    // errors, yet if ContinueOnError is set accordingly they won't fail the
+                    // build. We don't want to report those to the user.
                     return;
                 }
 
@@ -208,5 +232,12 @@ private sealed record class TargetRecord(string TargetName, bool IsMicrosoft, Da
 
             public TimeSpan Elapsed => Ended - Started;
         }
+
+        /// <summary>
+        /// Data about errors reported during design-time builds.
+        /// </summary>
+        /// <param name="TargetName">Names of the targets that reported the error. May be hashed. <see langword="null"/> if the target name could not be identified.</param>
+        /// <param name="ErrorCode">An error code that identifies the type of error.</param>
+        private sealed record class ErrorData(string? TargetName, string ErrorCode);
     }
 }

src/Microsoft.VisualStudio.ProjectSystem.Managed/Telemetry/TelemetryPropertyName.cs

@@ -199,9 +199,9 @@ public static class DesignTimeBuildComplete
         public const string ErrorCount = "vs.projectsystem.managed.designtimebuildcomplete.errorcount";
 
         /// <summary>
-        ///     The names of targets that failed during the design-time build.
+        ///     Data about errors that occur during design-time builds.
         /// </summary>
-        public const string ErrorTargets = "vs.projectsystem.managed.designtimebuildcomplete.errortargets";
+        public const string Errors = "vs.projectsystem.managed.designtimebuildcomplete.errors";
     }
 
     public static class SDKVersion

tests/Microsoft.VisualStudio.ProjectSystem.Managed.VS.UnitTests/ProjectSystem/VS/Rename/RenamerTestsBase.cs

@@ -1,6 +1,5 @@
 // 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.md file in the project root for more information.
 
-//using System;
 using EnvDTE;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.Text;