using System;

using System.Collections.Generic;

using System.ComponentModel.DataAnnotations;

using System.Reflection;

using System.Text.Json;

using System.Text.Json.Serialization;

using System.Text.Json.Serialization.Metadata;

public class Program

{

    public static void Main()

    {

        // Create test object and populate it with some data

        var parent = new Parent2()

        {

            Child = new Child2()

            {

                List = [

                    new() { Foo = "foo1", Bar = "bar1" },

                    new() { Foo = "foo2", Bar = "bar2" }

                    ]

            }

        };

​

        // Convert to and from JSON using Newtonsoft

        var json1 = Newtonsoft.Json.JsonConvert.SerializeObject(parent, JsonSerializerSettingsWrite);

        Console.WriteLine("Newtonsoft : Schema to JSON:");

        Console.WriteLine(json1);

        var schema1 = Newtonsoft.Json.JsonConvert.DeserializeObject<Parent2>(json1, JsonSerializerSettingsRead);

        Console.WriteLine("Newtonsoft : JSON to Schema:");

        Console.WriteLine(schema1);

​

        // Convert to and from JSON using Text.Json

        var json2 = JsonSerializer.Serialize(parent, JsonSerializerOptionsWrite);

        Console.WriteLine("Text.Json : Schema to JSON:");

        Console.WriteLine(json2);

        var schema2 = JsonSerializer.Deserialize<Parent2>(json2, JsonSerializerOptionsRead);

        Console.WriteLine("Text.Json : JSON to Schema:");

        Console.WriteLine(schema2);

​

        // Convert to and from JSON using Text.Json (without special settings)

        json2 = JsonSerializer.Serialize(parent);

        Console.WriteLine("Text.Json : Schema to JSON (no settings):");

        Console.WriteLine(json2);

        schema2 = JsonSerializer.Deserialize<Parent2>(json2);

        Console.WriteLine("Text.Json : JSON to Schema (no settings):");

        Console.WriteLine(schema2);

}

​

    private static readonly Newtonsoft.Json.JsonSerializerSettings JsonSerializerSettingsRead = new Newtonsoft.Json.JsonSerializerSettings

    {

        ObjectCreationHandling = Newtonsoft.Json.ObjectCreationHandling.Reuse

    };

​

    private static readonly Newtonsoft.Json.JsonSerializerSettings JsonSerializerSettingsWrite = new Newtonsoft.Json.JsonSerializerSettings

    {

        Formatting = Newtonsoft.Json.Formatting.Indented,

        StringEscapeHandling = Newtonsoft.Json.StringEscapeHandling.EscapeNonAscii,

        NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore,

        ContractResolver = new ExcludeObsoletePropertiesResolver()

    };

​

    private static readonly JsonSerializerOptions JsonSerializerOptionsRead = new JsonSerializerOptions

    {

        PreferredObjectCreationHandling = JsonObjectCreationHandling.Populate,

        ReadCommentHandling = JsonCommentHandling.Skip,

        AllowTrailingCommas = true

    };

    private static readonly JsonSerializerOptions JsonSerializerOptionsWrite = new JsonSerializerOptions

    {

        WriteIndented = true,

        DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull,

        TypeInfoResolver = new DefaultJsonTypeInfoResolver()

            .WithAddedModifier(ExcludeObsoleteProperties)

    };

​

    private static void ExcludeObsoleteProperties(JsonTypeInfo typeInfo)

    {

        if (typeInfo.Kind != JsonTypeInfoKind.Object)

            return;

        foreach (var property in typeInfo.Properties)

        {

            if (property.AttributeProvider?.IsDefined(typeof(ObsoleteAttribute), true) == true)

                property.ShouldSerialize = (_, _) => false;

        }

    }

}

​

public record Parent1

{

    // Child1 replaced by Child2

    [Obsolete]

    public Child1 Child { internal get; set; } = new();

}

​

public record Parent2 : Parent1

{

    public Parent2() { }

    public Parent2(Parent1 parent) : base(parent) { }

​

    // Child2 replaced Child1

    // This seems to make Text.Json unhappy

    [Required]

    public new Child2 Child { get; set; } = new();

}

​

public record Sub

{

    public string Foo;

    public string Bar;

}

​

public record Child1

{

    [Obsolete]

    public string CSV { internal get; set; } = "";

}

​

public record Child2 : Child1

{

    public Child2() { }

    public Child2(Child1 child) : base(child) { }

​

    [Required]

    public List<Sub> List { get; set; } = [];

}

​

public class ExcludeObsoletePropertiesResolver : Newtonsoft.Json.Serialization.DefaultContractResolver

{

    protected override List<MemberInfo> GetSerializableMembers(Type objectType)

    {

        var memberList = base.GetSerializableMembers(objectType);

        memberList.RemoveAll(item => item.IsDefined(typeof(ObsoleteAttribute), true));

        return memberList;

    }

}

​