Fix Issue Where WeakReference Delegate is Garbage Collected While Client is Alive

Mindscape.Raygun4Net.NetCore.Common/RaygunClientBase.cs

@@ -39,6 +39,13 @@ public abstract class RaygunClientBase
     private readonly ThrottledBackgroundMessageProcessor _backgroundMessageProcessor;
     private readonly IRaygunUserProvider _userProvider;
     protected internal const string SentKey = "AlreadySentByRaygun";
+
+    /// <summary>
+    /// Store a strong reference to the OnApplicationUnhandledException delegate so it does not get garbage collected while
+    /// the client is still alive
+    /// </summary>
+    private readonly UnhandledExceptionBridge.UnhandledExceptionHandler _onUnhandledExceptionDelegate;
+
 
     /// <summary>
     /// Raised just before a message is sent. This can be used to make final adjustments to the <see cref="RaygunMessage"/>, or to cancel the send.
@@ -116,8 +123,10 @@ protected RaygunClientBase(RaygunSettingsBase settings, HttpClient client, IRayg
       _userProvider = userProvider;
 
       _wrapperExceptions.Add(typeof(TargetInvocationException));
-
-      UnhandledExceptionBridge.OnUnhandledException(OnApplicationUnhandledException);
+
+      _onUnhandledExceptionDelegate = OnApplicationUnhandledException;
+
+      UnhandledExceptionBridge.OnUnhandledException(_onUnhandledExceptionDelegate);
     }
 
     /// <summary>

Mindscape.Raygun4Net.NetCore.Tests/UnhandledExceptionBridgeTests.cs

@@ -5,6 +5,14 @@ namespace Mindscape.Raygun4Net.NetCore.Tests
   [TestFixture]
   public class UnhandledExceptionBridgeTests
   {
+    private RaygunClientBase _strongRef;
+
+    [SetUp]
+    public void Setup()
+    {
+      _strongRef = new RaygunClient(new RaygunSettings(){CatchUnhandledExceptions = true, ApiKey = "dummy"});
+    }
+
     /// <summary>
     /// GitHub Issue: 513
     /// See https://github.com/MindscapeHQ/raygun4net/issues/513 for the issue report
@@ -45,5 +53,25 @@ void Callback(Exception e, bool b)
 
       Assert.That(observedException, Is.Null);
     }
+
+    [Test]
+    public void UnhandledExceptionBridge_WhenClientStillAlive_DelegateShouldStillBeAlive()
+    {
+      string errorMessage = null;
+
+      _strongRef.SendingMessage += (sender, args) =>
+      {
+        errorMessage = args.Message.Details.Error.Message; 
+      };
+
+      // Call GC, this should NOT GC the delegate which the UnhandledExceptionBridge holds for the RaygunClient's 
+      GC.Collect();
+      GC.WaitForPendingFinalizers();
+      GC.Collect();
+
+      UnhandledExceptionBridge.RaiseUnhandledException(new Exception("Alive"), false);
+
+      Assert.That(errorMessage, Is.Not.Null);
+    }
   }
 }