Initial support for OpenTelemetry (#6410)

Co-Authored-By: Hadi Eskandari <H.Eskandari@Gmail.com>
Co-authored-by: Mike Minutillo <mike.minutillo@particular.net>
Co-authored-by: Laila Bougria <laila.bougria@particular.net>
Co-authored-by: Tim Bussmann <tim.bussmann@particular.net>

Author: 4 people

src/NServiceBus.AcceptanceTests/Core/OpenTelemetry/ActivityTestingExtensions.cs

@@ -0,0 +1,38 @@
+namespace NServiceBus.AcceptanceTests.Core.OpenTelemetry;
+
+using System;
+using System.Collections.Immutable;
+using System.Diagnostics;
+using NUnit.Framework;
+
+public static class ActivityTestingExtensions
+{
+    public static void VerifyTag(this ImmutableDictionary<string, string> tags, string tagName, string expectedValue)
+    {
+        Assert.IsTrue(tags.TryGetValue(tagName, out var tagValue), $"Tags should contain key '{tagName}'");
+        Assert.AreEqual(expectedValue, tagValue, $"Tag value with key '{tagName}' is incorrect");
+    }
+
+    /// <summary>
+    /// Checks tags for duplicate tag keys.
+    /// </summary>
+    public static void VerifyUniqueTags(this Activity activity)
+    {
+        var tagsList = activity.Tags.ToImmutableList();
+
+        if (tagsList.Count < 2)
+        {
+            return;
+        }
+
+        var sortedTags = tagsList.Sort((a, b) => StringComparer.CurrentCultureIgnoreCase.Compare(a.Key, b.Key));
+
+        for (int i = 0; i < sortedTags.Count - 1; i++)
+        {
+            if (StringComparer.InvariantCultureIgnoreCase.Equals(sortedTags[i].Key, sortedTags[i + 1].Key))
+            {
+                Assert.Fail($"duplicate tag found: {sortedTags[i].Key}. Tags should be unique.");
+            }
+        }
+    }
+}

src/NServiceBus.AcceptanceTests/Core/OpenTelemetry/OpenTelemetryAcceptanceTest.cs

@@ -0,0 +1,19 @@
+namespace NServiceBus.AcceptanceTests.Core.OpenTelemetry;
+
+using NUnit.Framework;
+
+[NonParallelizable] // Ensure only activities for the current test are captured
+public class OpenTelemetryAcceptanceTest : NServiceBusAcceptanceTest
+{
+    protected TestingActivityListener NServicebusActivityListener { get; private set; }
+
+    [SetUp]
+    public void Setup() => NServicebusActivityListener = TestingActivityListener.SetupDiagnosticListener("NServiceBus.Core");
+
+    [TearDown]
+    public void Cleanup()
+    {
+        NServicebusActivityListener?.VerifyAllActivitiesCompleted();
+        NServicebusActivityListener?.Dispose();
+    }
+}