RangeOrPlaceholderRangeConverter.cs

using System;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using OmniSharp.Extensions.LanguageServer.Protocol.Models;
using Range = OmniSharp.Extensions.LanguageServer.Protocol.Models.Range;

namespace OmniSharp.Extensions.LanguageServer.Protocol.Serialization.Converters
{
    internal class RangeOrPlaceholderRangeConverter : JsonConverter<RangeOrPlaceholderRange>
    {
        public override void WriteJson(JsonWriter writer, RangeOrPlaceholderRange value, JsonSerializer serializer)
        {
            if (value.IsRange)
            {
                serializer.Serialize(writer, value.Range);
            }
            else if (value.IsPlaceholderRange)
            {
                serializer.Serialize(writer, value.PlaceholderRange);
            }
            else
            {
                writer.WriteNull();
            }
        }

        public override RangeOrPlaceholderRange ReadJson(
            JsonReader reader, Type objectType, RangeOrPlaceholderRange existingValue, bool hasExistingValue, JsonSerializer serializer
        )
        {
            if (reader.TokenType is JsonToken.StartObject)
            {
                var obj = JToken.ReadFrom(reader) as JObject;
                return obj.ContainsKey("placeholder")
                    ? new RangeOrPlaceholderRange(obj.ToObject<PlaceholderRange>())
                    : new RangeOrPlaceholderRange(obj.ToObject<Range>());
            }

            return null;
        }
    }
}