Json.net how to serialize object as value

Question

I\'ve pored through the docs, StackOverflow, etc., can\'t seem to find this...

What I want to do is serialize/deserialize a simple value-type of object as a value, n

Answer 1

This is a answer to Customise NewtonSoft.Json for Value Object serialisation, in regards to value objects in DDD. But that question is marked as duplicate to this one, which i don't think is completely true.

I borrowed the code for the ValueObjectConverter from https://github.com/eventflow/EventFlow, I have only done minor changes.

using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using FluentAssertions;
using Newtonsoft.Json;
using Xunit;

namespace Serialization
{
    public class ValueObjectSerializationTests
    {
        class SomeClass
        {
            public IPAddress IPAddress { get; set; }
        }

        [Fact]
        public void FactMethodName()
        {
            var given = new SomeClass
            {
                IPAddress = new IPAddress("192.168.1.2")
            };

            var jsonSerializerSettings = new JsonSerializerSettings()
            {
                Converters = new List
                             {
                                new ValueObjectConverter()
                             }
            };
            var json = JsonConvert.SerializeObject(given, jsonSerializerSettings);

            var result = JsonConvert.DeserializeObject(json, jsonSerializerSettings);

            var expected = new SomeClass
            {
                IPAddress = new IPAddress("192.168.1.2")
            };

            json.Should().Be("{\"IPAddress\":\"192.168.1.2\"}");
            expected.ShouldBeEquivalentTo(result);
        }
    }

    public class IPAddress:IValueObject
    {
        public IPAddress(string value)
        {
            Value = value;
        }

        public object GetValue()
        {
            return Value;
        }

        public string Value { get; private set; }
    }

    public interface IValueObject
    {
        object GetValue();
    }

    public class ValueObjectConverter : JsonConverter
    {
        private static readonly ConcurrentDictionary ConstructorArgumenTypes = new ConcurrentDictionary();

        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
        {
            if (!(value is IValueObject valueObject))
            {
                return;
            }

            serializer.Serialize(writer, valueObject.GetValue());
        }

        public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
        {
            var parameterType = ConstructorArgumenTypes.GetOrAdd(
                objectType,
                t =>
                {
                    var constructorInfo = objectType.GetConstructors(BindingFlags.Public | BindingFlags.Instance).First();
                    var parameterInfo = constructorInfo.GetParameters().Single();
                    return parameterInfo.ParameterType;
                });

            var value = serializer.Deserialize(reader, parameterType);
            return Activator.CreateInstance(objectType, new[] { value });
        }

        public override bool CanConvert(Type objectType)
        {
            return typeof(IValueObject).IsAssignableFrom(objectType);
        }
    }
}