using System;

using System.Collections;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Runtime.Serialization.Formatters;

using System.IO;

using System.Data;

using System.ComponentModel.DataAnnotations;

using System.Globalization;

using System.Reflection;

using System.Collections.ObjectModel;

​

using System.Text.Json;

using System.Text.Json.Serialization;

using System.Text.Json.Serialization.Metadata;

using System.Text.Json.Nodes;

​

using NUnit.Framework; // Throws NUnit.Framework.AssertionException

​

#nullable enable

​

​

//https://stackoverflow.com/questions/78348855/net-6-type-agnostic-json-serialization-with-camelcase-through-propertynamingp

​

    public class NamingPolicyJsonNodeConverter : JsonConverter<JsonNode>

    {

        public override bool CanConvert(Type typeToConvert) => typeof(JsonNode).IsAssignableFrom(typeToConvert) && !typeof(JsonValue).IsAssignableFrom(typeToConvert);

        public override void Write(Utf8JsonWriter writer, JsonNode? value, JsonSerializerOptions options) 

        {

            var namingPolicy = options.PropertyNamingPolicy;

            switch (value)

            {

                case JsonObject obj:

                    writer.WriteStartObject();

                    foreach (var pair in obj)

                    {

                        writer.WritePropertyName(namingPolicy?.ConvertName(pair.Key) ?? pair.Key);

                        Write(writer, pair.Value, options);

                    }

                    writer.WriteEndObject();

                    break;

                case JsonArray array: // We need to handle JsonArray explicitly to ensure that objects inside arrays have their properties renamed

                    writer.WriteStartArray();

                    foreach (var item in array)

                        Write(writer, item, options);

                    writer.WriteEndArray();

                    break;

                case null:

                    writer.WriteNullValue();

                    break;

                default: // JsonValue

                    value.WriteTo(writer, options);

                    break;

            }

        }

        public override JsonNode? Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options) => JsonNode.Parse(ref reader);

    }

​

​

    class TestClass

    {

        public static void Test()

        {

            var inputJson = GetJson();

            var options = new JsonSerializerOptions

            {

                Converters = { new NamingPolicyJsonNodeConverter() },

                PropertyNamingPolicy = JsonNamingPolicy.CamelCase,

                WriteIndented = true,

            };

            // Parse or deserialize the JSON using one of the two methods:

            // var node = JsonSerializer.Deserialize<JsonNode>(inputJson, options);

            var node = JsonNode.Parse(inputJson);   

            // Then serializing using the specified options + converter to remap property names:

            var outputJson = JsonSerializer.Serialize(node, options);

            Console.WriteLine("Re-serialized JSON:");

            Console.WriteLine(outputJson);

            Console.WriteLine("\nOriginal JSON:");

            Console.WriteLine(inputJson);

        }   

        static string GetJson() =>

@"[

   [

      {

         ""Glossary"":{

            ""Title"":""example glossary"",

            ""GlossDiv"":{

               ""Title"":""S"",

               ""GlossList"":[

                  {

                     ""GlossEntry"":{

                        ""ID"":""SGML"",

                        ""SortAs"":""SGML"",

                        ""GlossTerm"":""Standard Generalized Markup Language"",

                        ""Acronym"":""SGML"",

                        ""IsISO"" : true,

                        ""Abbrev"":""ISO 8879:1986"",

                        ""GlossDef"":[

                           {

                              ""PARA"":""A meta-markup language, used to create markup languages such as DocBook."",

                              ""GlossSeeAlso"":[

                                 ""GML"",

                                 ""XML""

                              ]

                           }

                        ],

                        ""GlossSee"":""markup""

                     }

                  }

               ]

            }

         }

      }

   ]

]

";

    }

​

    public class Program

    {

        public static void Main()

        {

            Console.WriteLine("Environment version: {0} ({1}), {2}", System.Runtime.InteropServices.RuntimeInformation.FrameworkDescription , Environment.Version, Environment.OSVersion);

            Console.WriteLine("System.Text.Json version: " + typeof(JsonSerializer).Assembly.FullName);

            Console.WriteLine();

​

            try

            {

                TestClass.Test();

            }

            catch (Exception ex)

            {

                Console.WriteLine("Failed with unhandled exception: ");

                Console.WriteLine(ex);

                throw;

            }

        }

    }

​