chore: add ManagedReference YAML roundtrip tests

src/Docfx.DataContracts.Common/JTokenConverter.cs

@@ -2,7 +2,6 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System.Reflection;
-using System.Text.Json;
 using Docfx.Common;
 using Newtonsoft.Json.Linq;
 
@@ -22,22 +21,23 @@ public static T Convert<T>(object obj)
             return jToken.ToObject<T>();
         }
 
-
-        var type = typeof(T);
-
-        // Try to convert `List<object>` to T (`ObjectToInferredTypesConverter`)
-        // Currently `ObjectToInferredTypesConverter` convert item to List<object>. So it need to convert type.
-        if (obj is List<object> list
-         && type.GetTypeInfo().IsGenericType
-         && type.GetGenericTypeDefinition() == typeof(List<>))
+        // Custom code path for `System.Text.Json` deserialization.
+        // `ObjectToInferredTypesConverter` deserialize items as `List<object>`.
+        // So it need to convert `List<object>` to `List<TItem>`.
+        if (obj is List<object> list && IsListType<T>())
         {
-            // TODO: performance optimization.
             var json = JsonUtility.Serialize(list);
             var result = JsonUtility.Deserialize<T>(new StringReader(json));
             return result;
         }
 
-
         throw new InvalidCastException();
     }
+
+    private static bool IsListType<T>()
+    {
+        var type = typeof(T);
+        return type.GetTypeInfo().IsGenericType
+            && type.GetGenericTypeDefinition() == typeof(List<>);
+    }
 }