fix findings

src/WireMock.Net.Minimal/Settings/WireMockServerSettingsParser.cs

@@ -276,7 +276,7 @@ public static class WireMockServerSettingsParser
         var defaultJsonBodyTransformer = parser.GetStringValue(nameof(WireMockServerSettings.DefaultJsonBodyTransformer));
         settings.DefaultJsonBodyTransformer = defaultJsonBodyTransformer switch
         {
-            nameof(SystemTextJsonBodyTransformer) => new SystemTextJsonBodyTransformer(),
+            nameof(SystemTextJsonBodyTransformer) => new SystemTextJsonBodyTransformer(settings),
             _ => new NewtonsoftJsonBodyTransformer(settings),
         };
     }

src/WireMock.Net.Shared/Transformers/NewtonsoftJsonBodyTransformer.cs

@@ -86,6 +86,7 @@ public class NewtonsoftJsonBodyTransformer(WireMockServerSettings settings) : IJ
             }
             catch
             {
+                settings.Logger.Warn("Failed to parse string ''{0}'' as JSON. Returning the original string value.", stringValue);
             }
         }
 

src/WireMock.Net.Shared/Transformers/SystemTextJsonBodyTransformer.cs

@@ -6,6 +6,7 @@ using System.Text.Json.Nodes;
 using HandlebarsDotNet.Helpers.Models;
 using JetBrains.Annotations;
 using JsonConverter.System.Text.Json;
+using WireMock.Settings;
 using WireMock.Types;
 using WireMock.Util;
 
@@ -15,7 +16,7 @@ namespace WireMock.Transformers;
 /// JSON body transformer implementation based on System.Text.Json.
 /// </summary>
 [PublicAPI]
-public class SystemTextJsonBodyTransformer() : IJsonBodyTransformer
+public class SystemTextJsonBodyTransformer(WireMockServerSettings settings) : IJsonBodyTransformer
 {
     private static readonly SystemTextJsonConverter _jsonConverter = new();
 
@@ -85,7 +86,7 @@ public class SystemTextJsonBodyTransformer() : IJsonBodyTransformer
             }
             catch
             {
-                // Ignore and return as string.
+                settings.Logger.Warn("Failed to parse string ''{0}'' as JSON. Returning the original string value.", stringValue);
             }
         }
 

test/WireMock.Net.Tests/Transformers/JsonBodyTransformerTests.cs

@@ -19,15 +19,17 @@ public class JsonBodyTransformerTests
     {
         get
         {
+            var settings = new WireMockServerSettings();
+
             return
             [
                 new JsonBodyTransformerTestContext(
-                    () => new NewtonsoftJsonBodyTransformer(new WireMockServerSettings()),
+                    () => new NewtonsoftJsonBodyTransformer(settings),
                     JObject.Parse,
                     body => ((JToken)body).ToString(Formatting.None)),
 
                 new JsonBodyTransformerTestContext(
-                    () => new SystemTextJsonBodyTransformer(),
+                    () => new SystemTextJsonBodyTransformer(settings),
                     json => JsonNode.Parse(json)!,
                     body => ((JsonNode)body).ToJsonString())
             ];