improve eventsource tests - part 1 (#3586)

src/OpenTelemetry/Internal/OpenTelemetrySdkEventSource.cs

@@ -195,7 +195,7 @@ namespace OpenTelemetry.Internal
         [Event(3, Message = "Exporter returned error '{0}'.", Level = EventLevel.Warning)]
         public void ExporterErrorResult(ExportResult exportResult)
         {
-            this.WriteEvent(3, exportResult.ToString());
+            this.WriteEvent(3, exportResult);
         }
 
         [Event(4, Message = "Unknown error in SpanProcessor event '{0}': '{1}'.", Level = EventLevel.Error)]

test/OpenTelemetry.Exporter.Prometheus.Tests/EventSourceTest.cs

@@ -0,0 +1,29 @@
+// <copyright file="EventSourceTest.cs" company="OpenTelemetry Authors">
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+// </copyright>
+
+using OpenTelemetry.Tests;
+using Xunit;
+
+namespace OpenTelemetry.Exporter.Prometheus.Tests;
+
+public class EventSourceTest
+{
+    [Fact]
+    public void EventSourceTest_PrometheusExporterEventSource()
+    {
+        EventSourceTestHelper.MethodsAreImplementedConsistentlyWithTheirAttributes(PrometheusExporterEventSource.Log);
+    }
+}

test/OpenTelemetry.Exporter.Prometheus.Tests/OpenTelemetry.Exporter.Prometheus.Tests.csproj

@@ -29,6 +29,8 @@
   </ItemGroup>
 
   <ItemGroup>
+    <Compile Include="$(RepoRoot)\test\OpenTelemetry.Tests\Shared\EventSourceTestHelper.cs" Link="EventSourceTestHelper.cs" />
+    <Compile Include="$(RepoRoot)\test\OpenTelemetry.Tests\Shared\TestEventListener.cs" Link="TestEventListener.cs" />
     <Compile Include="$(RepoRoot)\test\OpenTelemetry.Tests\Shared\Utils.cs" Link="Includes\Utils.cs" />
   </ItemGroup>
 

test/OpenTelemetry.Tests/Shared/EventSourceTestHelper.cs

@@ -42,17 +42,24 @@ namespace OpenTelemetry.Tests
                 object[] eventArguments = GenerateEventArguments(eventMethod);
                 eventMethod.Invoke(eventSource, eventArguments);
 
-                EventWrittenEventArgs actualEvent = null;
+                EventWrittenEventArgs actualEvent = listener.Messages.FirstOrDefault(x => x.EventName == eventMethod.Name);
 
-                actualEvent = listener.Messages.First(q => q.EventName == eventMethod.Name);
+                if (actualEvent == null)
+                {
+                    // check for errors
+                    actualEvent = listener.Messages.FirstOrDefault(x => x.EventId == 0);
+                    if (actualEvent != null)
+                    {
+                        throw new Exception(actualEvent.Message);
+                    }
+
+                    // give up
+                    throw new Exception("Listener failed to collect event.");
+                }
 
                 VerifyEventId(eventMethod, actualEvent);
                 VerifyEventLevel(eventMethod, actualEvent);
-
-                if (eventMethod.Name != "ExporterErrorResult")
-                {
-                    VerifyEventMessage(eventMethod, actualEvent, eventArguments);
-                }
+                VerifyEventMessage(eventMethod, actualEvent, eventArguments);
             }
             catch (Exception e)
             {

test/OpenTelemetry.Tests/Shared/TestEventListener.cs

@@ -26,8 +26,11 @@ namespace OpenTelemetry.Tests
     /// </summary>
     internal class TestEventListener : EventListener
     {
+        /// <summary>Unique Id used to identify events from the test thread.</summary>
+        private readonly Guid activityId;
+
         /// <summary>A queue of events that have been logged.</summary>
-        private readonly Queue<EventWrittenEventArgs> events;
+        private readonly List<EventWrittenEventArgs> events;
 
         /// <summary>
         /// Lock for event writing tracking.
@@ -39,11 +42,14 @@ namespace OpenTelemetry.Tests
         /// </summary>
         public TestEventListener()
         {
-            this.events = new Queue<EventWrittenEventArgs>();
+            this.activityId = Guid.NewGuid();
+            EventSource.SetCurrentThreadActivityId(this.activityId);
+
+            this.events = new List<EventWrittenEventArgs>();
             this.eventWritten = new AutoResetEvent(false);
             this.OnOnEventWritten = e =>
             {
-                this.events.Enqueue(e);
+                this.events.Add(e);
                 this.eventWritten.Set();
             };
         }
@@ -55,7 +61,7 @@ namespace OpenTelemetry.Tests
         public Action<EventWrittenEventArgs> OnOnEventWritten { get; set; }
 
         /// <summary>Gets the events that have been written.</summary>
-        public IEnumerable<EventWrittenEventArgs> Messages
+        public IList<EventWrittenEventArgs> Messages
         {
             get
             {
@@ -64,10 +70,7 @@ namespace OpenTelemetry.Tests
                     this.eventWritten.WaitOne(TimeSpan.FromSeconds(5));
                 }
 
-                while (this.events.Count != 0)
-                {
-                    yield return this.events.Dequeue();
-                }
+                return this.events;
             }
         }
 
@@ -83,7 +86,10 @@ namespace OpenTelemetry.Tests
         /// <param name="eventData">The event data that was written.</param>
         protected override void OnEventWritten(EventWrittenEventArgs eventData)
         {
-            this.OnOnEventWritten(eventData);
+            if (eventData.ActivityId == this.activityId)
+            {
+                this.OnOnEventWritten(eventData);
+            }
         }
 
         /// <summary>Handler for event source creation.</summary>