Send telemetry on unhandled exceptions inside the AnalysisQueue (#460)

* Telemetrize unhandled AnalysisQueue exceptions

* make the main exception the inner one instead

* don't bother sending isTerminating, we always send false

* rename function, event name

Author: jakebailey

src/LanguageServer/Impl/LanguageServer.cs

@@ -45,6 +45,7 @@ public sealed partial class LanguageServer : IDisposable {
 
         private IServiceContainer _services;
         private IUIService _ui;
+        private ITelemetryService2 _telemetry;
 
         private JsonRpc _rpc;
         private JsonSerializer _jsonSerializer;
@@ -60,10 +61,11 @@ public CancellationToken Start(IServiceContainer services, JsonRpc rpc) {
             _ui = services.GetService<IUIService>();
             _rpc = rpc;
             _jsonSerializer = services.GetService<JsonSerializer>();
+            _telemetry = services.GetService<ITelemetryService2>();
 
             var progress = services.GetService<IProgressService>();
 
-            var rpcTraceListener = new TelemetryRpcTraceListener(services.GetService<ITelemetryService2>());
+            var rpcTraceListener = new TelemetryRpcTraceListener(_telemetry);
             _rpc.TraceSource.Listeners.Add(rpcTraceListener);
 
             _server.OnLogMessage += OnLogMessage;
@@ -72,6 +74,7 @@ public CancellationToken Start(IServiceContainer services, JsonRpc rpc) {
             _server.OnApplyWorkspaceEdit += OnApplyWorkspaceEdit;
             _server.OnRegisterCapability += OnRegisterCapability;
             _server.OnUnregisterCapability += OnUnregisterCapability;
+            _server.AnalysisQueue.UnhandledException += OnAnalysisQueueUnhandledException;
 
             _disposables
                 .Add(() => _server.OnLogMessage -= OnLogMessage)
@@ -80,6 +83,7 @@ public CancellationToken Start(IServiceContainer services, JsonRpc rpc) {
                 .Add(() => _server.OnApplyWorkspaceEdit -= OnApplyWorkspaceEdit)
                 .Add(() => _server.OnRegisterCapability -= OnRegisterCapability)
                 .Add(() => _server.OnUnregisterCapability -= OnUnregisterCapability)
+                .Add(() => _server.AnalysisQueue.UnhandledException -= OnAnalysisQueueUnhandledException)
                 .Add(() => _shutdownCts.Cancel())
                 .Add(_prioritizer)
                 .Add(() => _pathsWatcher?.Dispose())
@@ -454,6 +458,16 @@ private void HandlePathWatchChange(JToken section) {
             _searchPaths = _initParams.initializationOptions.searchPaths;
         }
 
+        private void OnAnalysisQueueUnhandledException(object sender, UnhandledExceptionEventArgs e) {
+            if (!(e.ExceptionObject is Exception ex)) {
+                Debug.Fail($"ExceptionObject was {e.ExceptionObject.GetType()}, not Exception");
+                return;
+            }
+
+            var te = Telemetry.CreateEventWithException("analysis_queue.unhandled_exception", ex);
+            _telemetry.SendTelemetry(te).DoNotWait();
+        }
+
         private class Prioritizer : IDisposable {
             private const int InitializePriority = 0;
             private const int ConfigurationPriority = 1;

src/LanguageServer/Impl/Telemetry.cs

@@ -27,6 +27,26 @@ internal class Telemetry {
         public static TelemetryEvent CreateEvent(string eventName) => new TelemetryEvent {
             EventName = EventPrefix + eventName,
         };
+
+        public static TelemetryEvent CreateEventWithException(string eventName, Exception e) {
+            var te = CreateEvent(eventName);
+
+            if (e is AggregateException ae && ae.InnerException != null) {
+                te.Properties["outerName"] = e.GetType().Name;
+                te.Properties["outerStackTrace"] = e.StackTrace;
+
+                e = ae.Flatten();
+
+                while (e.InnerException != null) {
+                    e = e.InnerException;
+                }
+            }
+
+            te.Properties["name"] = e.GetType().Name;
+            te.Properties["stackTrace"] = e.StackTrace;
+
+            return te;
+        }
     }
 
     internal class TelemetryRpcTraceListener : TraceListener {
@@ -72,10 +92,8 @@ public override void TraceData(TraceEventCache eventCache, string source, TraceE
                 return;
             }
 
-            var e = Telemetry.CreateEvent("rpc.exception");
+            var e = Telemetry.CreateEventWithException("rpc.exception", exception);
             e.Properties["method"] = method;
-            e.Properties["name"] = exception.GetType().Name;
-            e.Properties["stackTrace"] = exception.StackTrace;
 
             _telemetryService.SendTelemetry(e).DoNotWait();
         }