update to use ReferenceHandler.Preserve to break circular references …

…in serialization

src/protagonist/API/Infrastructure/Messaging/AssetNotificationSender.cs

@@ -1,5 +1,6 @@
 using System.Collections.Generic;
 using System.Text.Json;
+using System.Text.Json.Serialization;
 using DLCS.AWS.SNS;
 using DLCS.Core.Collections;
 using DLCS.Core.Strings;
@@ -18,7 +19,10 @@ public class AssetNotificationSender : IAssetNotificationSender
     private readonly ILogger<AssetNotificationSender> logger;
     private readonly ITopicPublisher topicPublisher;
     private readonly IPathCustomerRepository customerPathRepository;
-    private readonly JsonSerializerOptions settings = new(JsonSerializerDefaults.Web);
+    private readonly JsonSerializerOptions settings = new(JsonSerializerDefaults.Web)
+    {
+        ReferenceHandler = ReferenceHandler.Preserve
+    };
 
     private readonly Dictionary<int, CustomerPathElement> customerPathElements = new();
 

src/protagonist/DLCS.Repository/Messaging/EngineClient.cs

@@ -4,6 +4,7 @@
 using System.Net.Http;
 using System.Text;
 using System.Text.Json;
+using System.Text.Json.Serialization;
 using System.Threading;
 using System.Threading.Tasks;
 using DLCS.AWS.SQS;
@@ -26,7 +27,10 @@ public class EngineClient : IEngineClient
     private readonly ILogger<EngineClient> logger;
     private readonly DlcsSettings dlcsSettings;
 
-    private static readonly JsonSerializerOptions SerializerOptions = new(JsonSerializerDefaults.Web);
+    private static readonly JsonSerializerOptions SerializerOptions = new (JsonSerializerDefaults.Web)
+    {
+        ReferenceHandler = ReferenceHandler.Preserve
+    };
 
     public EngineClient(
         IQueueLookup queueLookup,