Fix and add a test

Author: zlepper

Rebus.Diagnostics.Tests/Incoming/HandlerInvokerWrapperTests.cs

@@ -1,4 +1,6 @@
-using System.Diagnostics;
+using System;
+using System.Diagnostics;
+using System.Linq;
 using System.Threading.Tasks;
 using NUnit.Framework;
 using Rebus.Diagnostics.Incoming;
@@ -41,6 +43,40 @@ public async Task CreatesNewSubActivityIfThereIsAnActiveActivity()
             Assert.That(hadActivity);
         }
 
+        [Test]
+        public async Task MarksActivityAsFailedIfHandlerThrows()
+        {
+            using var activity = new Activity("MyActivity");
+
+            Activity? innerActivity = null;
+            var innerInvoker = new TestInvoker(() =>
+            {
+                innerActivity = Activity.Current;
+                throw new Exception("Look im failing");
+            });
+
+            var wrapper = new HandlerInvokerWrapper(innerInvoker, "MyMessage");
+
+            activity.Start();
+
+            Assume.That(activity, Is.SameAs(Activity.Current));
+
+            Assert.That(async () =>
+            {
+                await wrapper.Invoke();
+            }, Throws.Exception);
+
+            
+            Assert.That(innerActivity, Is.Not.Null);
+
+            Assert.That(innerActivity!.Status, Is.EqualTo(ActivityStatusCode.Error));
+            Assert.That(innerActivity!.StatusDescription, Is.EqualTo("Look im failing"));
+            Assert.That(innerActivity.Events, Has.Exactly(1).Items);
+            var ev = innerActivity.Events.Single();
+            Assert.That(ev.Tags.FirstOrDefault(t => t.Key == "exception.type").Value, Is.EqualTo("System.Exception"));
+            Assert.That(ev.Tags.FirstOrDefault(t => t.Key == "exception.message").Value, Is.EqualTo("Look im failing"));
+        }
+
         [Test]
         public async Task CreatesNoNewActivityIfThereIsntAlreadyAnActiveActivity()
         {

Rebus.Diagnostics/Diagnostics/Incoming/HandlerInvokerWrapper.cs

@@ -35,7 +35,7 @@ public override async Task Invoke()
                 initialTags.Add(tag.Key, tag.Value);
         }
         initialTags["messaging.operation"] = "process";
-        initialTags["rebus.handler.type"] = _handlerInvokerImplementation.Handler.GetType().FullName;
+        initialTags["rebus.handler.type"] = _handlerInvokerImplementation.Handler?.GetType().FullName ?? "Unknown handler type";
 
         using var activity = RebusDiagnosticConstants.ActivitySource.StartActivity($"{_messageType} process", ActivityKind.Internal, parentActivity.Context, initialTags);
 
@@ -48,7 +48,7 @@ public override async Task Invoke()
         catch (Exception e)
         {
             activity?.AddException(e);
-            activity?.SetStatus(ActivityStatusCode.Error, e.ToString());
+            activity?.SetStatus(ActivityStatusCode.Error, e.Message);
             throw;
         }
     }