Added System.Text.Json serialization-based JsonPatch implementation

src/Features/JsonPatch.SystemTextJson/src/Helpers/JsonUtilities.cs

@@ -1,6 +1,7 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+using System;
 using System.Text.Json;
 using System.Text.Json.Nodes;
 
@@ -10,8 +11,41 @@ internal static class JsonUtilities
 {
     public static bool DeepEquals(object a, object b, JsonSerializerOptions serializerOptions)
     {
-        return JsonObject.DeepEquals(
-            JsonSerializer.SerializeToNode(a, serializerOptions),
-            JsonSerializer.SerializeToNode(b, serializerOptions));
+        if (a == null && b == null)
+        {
+            return true;
+        }
+
+        if (a == null || b == null)
+        {
+            return false;
+        }
+
+        if (a.GetType() == typeof(JsonNode) && b.GetType() == typeof(JsonNode))
+        {
+            return JsonNode.DeepEquals((JsonNode)a, (JsonNode)b);
+        }
+
+        using var docA = TryGetJsonElement(a, serializerOptions, out var elementA);
+        using var docB = TryGetJsonElement(b, serializerOptions, out var elementB);
+
+        return JsonElement.DeepEquals(elementA, elementB);
+    }
+
+    private static IDisposable TryGetJsonElement(object item, JsonSerializerOptions serializerOptions, out JsonElement element)
+    {
+        IDisposable result = null;
+        if (item is JsonElement jsonElement)
+        {
+            element = jsonElement;
+        }
+        else
+        {
+            var docA = JsonSerializer.SerializeToDocument(item, serializerOptions);
+            element = docA.RootElement;
+            result = docA;
+        }
+
+        return result;
     }
 }

src/Features/JsonPatch.SystemTextJson/src/Internal/ConversionResultProvider.cs

@@ -56,7 +56,7 @@ internal static ConversionResult CopyTo(object value, Type typeToConvertTo, Json
         // Workaround for the https://github.com/dotnet/runtime/issues/113926
         if (targetType.Name == "JsonValuePrimitive`1")
         {
-            targetType = typeof(JsonNode);
+            targetType = typeof(JsonElement);
         }
 
         try
@@ -84,6 +84,12 @@ private static bool IsNullableType(Type type)
 
     private static object ConvertToTargetType(object value, Type targetType, JsonSerializerOptions serializerOptions)
     {
-        return JsonSerializer.Deserialize(JsonSerializer.Serialize(value, serializerOptions), targetType, serializerOptions);
+        if (value is JsonElement jsonElement)
+        {
+            return JsonSerializer.Deserialize(jsonElement, targetType, serializerOptions);
+        }
+
+        using JsonDocument doc = JsonSerializer.SerializeToDocument(value, serializerOptions);
+        return JsonSerializer.Deserialize(doc.RootElement, targetType, serializerOptions);
     }
 }

src/Features/JsonPatch.SystemTextJson/src/Internal/ListAdapter.cs

@@ -5,7 +5,6 @@
 using System.Collections;
 using System.Collections.Generic;
 using System.Text.Json;
-using System.Text.Json.Nodes;
 using Microsoft.AspNetCore.JsonPatch.SystemTextJson.Helpers;
 using Microsoft.Extensions.Internal;
 
@@ -257,10 +256,6 @@ protected virtual bool TryGetPositionInfo(int collectionCount, string segment, O
         }
     }
 
-    /// <summary>
-    /// This API supports infrastructure and is not intended to be used
-    /// directly from your code. This API may change or be removed in future releases.
-    /// </summary>
     protected readonly struct PositionInfo
     {
         public PositionInfo(PositionType type, int index)
@@ -273,10 +268,6 @@ public PositionInfo(PositionType type, int index)
         public int Index { get; }
     }
 
-    /// <summary>
-    /// This API supports infrastructure and is not intended to be used
-    /// directly from your code. This API may change or be removed in future releases.
-    /// </summary>
     protected enum PositionType
     {
         Index, // valid index
@@ -285,10 +276,6 @@ protected enum PositionType
         OutOfBounds
     }
 
-    /// <summary>
-    /// This API supports infrastructure and is not intended to be used
-    /// directly from your code. This API may change or be removed in future releases.
-    /// </summary>
     protected enum OperationType
     {
         Add,

src/Features/JsonPatch.SystemTextJson/src/JsonPatchDocumentOfT.cs

@@ -713,19 +713,14 @@ private List<string> GetPathSegments(Expression expr)
 
     private string GetPropertyNameFromMemberExpression(MemberExpression memberExpression)
     {
-        var jsonObjectContract = SerializerOptions.GetTypeInfo(memberExpression.Expression.Type);
-        if (jsonObjectContract != null)
+        var jsonTypeInfo = SerializerOptions.GetTypeInfo(memberExpression.Expression.Type);
+        if (jsonTypeInfo != null)
         {
-            var jsonName = memberExpression.Member.Name;
-            var propNameAttribute = memberExpression.Member.GetCustomAttribute<JsonPropertyNameAttribute>();
-            if (propNameAttribute is not null)
-            {
-                jsonName = propNameAttribute.Name;
-            }
-
-            return jsonObjectContract.Properties
-                .First(jsonProperty => jsonProperty.Name == jsonName)
-                .Name;
+            var memberInfo = memberExpression.Member;
+            var matchingProp = jsonTypeInfo
+                .Properties
+                .First(jsonProp => jsonProp.AttributeProvider is MemberInfo mi && mi == memberInfo);
+            return matchingProp.Name;
         }
 
         return null;