System.Text.Json - Converters because the current one can't

DictionaryJsonConverter.cs

/* Copyright Xeno Innovations, Inc. 2020
 * Date:    2020-8-30
 * File:    DictionaryJsonConverter.cs
 * Description:
 *  Dictionary JSON Converter
 *
 * Reference:
 *  - https://github.com/dotnet/runtime/blob/master/src/libraries/System.Text.Json/tests/Serialization/CustomConverterTests/CustomConverterTests.DictionaryGuidConverter.cs
 *  - https://github.com/dotnet/runtime/issues/30524
 */

using System;
using System.Collections.Generic;
using System.Reflection;
using System.Text.Json;
using System.Text.Json.Serialization;

namespace SampleApp.Core.Converters
{
  public class DictionaryJsonConverter<TKey, TValue>
    : JsonConverter<Dictionary<TKey, TValue>>
  {
    private readonly Converter<string, TKey> _keyParser;

    private readonly Converter<TKey, string> _keySerializer;

    public DictionaryJsonConverter(Converter<string, TKey> keyParser, Converter<TKey, string> keySerializer)
    {
      _keyParser = keyParser;
      _keySerializer = keySerializer;
    }

    public static Dictionary<TKey, TValue> Read(
      ref Utf8JsonReader reader,
      Converter<string, TKey> keyParser,
      JsonSerializerOptions options)
    {
      if (reader.TokenType == JsonTokenType.Null)
        return null;

      if (reader.TokenType != JsonTokenType.StartObject)
        throw new JsonException("Dictionary must be JSON object.");

      var result = new Dictionary<TKey, TValue>();

      while (true)
      {
        if (!reader.Read())
          throw new JsonException("Incomplete JSON object");

        if (reader.TokenType == JsonTokenType.EndObject)
          return result;

        var key = keyParser(reader.GetString());

        if (!reader.Read())
          throw new JsonException("Incomplete JSON object");

        var value = JsonSerializer.Deserialize<TValue>(ref reader, options);
        result.Add(key, value);
      }
    }

    public override Dictionary<TKey, TValue> Read(
      ref Utf8JsonReader reader,
      Type typeToConvert,
      JsonSerializerOptions options)
    {
      return Read(ref reader, _keyParser, options);
    }

    public override void Write(
      Utf8JsonWriter writer,
      Dictionary<TKey, TValue> value,
      JsonSerializerOptions options)
    {
      if (value is null)
      {
        writer.WriteNullValue();
      }
      else
      {
        writer.WriteStartObject();

        foreach (var pair in value)
        {
          writer.WritePropertyName(_keySerializer(pair.Key));
          JsonSerializer.Serialize(writer, pair.Value, options);
        }

        writer.WriteEndObject();
      }
    }
  }
}

TimeSpanJsonConverter.cs

/* Copyright Xeno Innovations, Inc. 2020
 * Date:    2020-8-30
 * File:    TimeSpanJsonConverter.cs
 * Description:
 *  TimeStamp JSON Convert for System.Text.Json
 */

using System;
using System.Text.Json;
using System.Text.Json.Serialization;

namespace SampleApp.Core.Converters
{
  public class TimeSpanJsonConverter : JsonConverter<TimeSpan>
  {
    public override TimeSpan Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
    {
      return TimeSpan.Parse(reader.GetString());
    }

    public override void Write(Utf8JsonWriter writer, TimeSpan value, JsonSerializerOptions options)
    {
      writer.WriteStringValue(value.ToString());
    }
  }
}