Serialization and deserialization with TypeNameHandling.All looses information about Guid type

[centur]

Hi,
there might be a bug in SerializeObject when settings have jsonSerializerSettings.TypeNameHandling = TypeNameHandling.All

Here is the small LinqPad repro of this issue
JsonNetBug.zip

The output of the attached code is the following:

======Original Dictionary :
I'm Guid - System.Guid
======Deserialized Dictionary :
I'm Guid - System.String

Although Json.NET can successfully serialize and deserialize Guid when it's an object property, it looses type (struct in this case) information when it's in a collection.

[gabikliot]

Am I to understand that this is "by design" according to #728 (comment)?

I tried to write a converter for Guid, but it did not work.
Could you please provide more/exact details of how this can be fixed?

I wrote:

public class GuidConverter : JsonConverter
{
    public override bool CanConvert(Type objectType)
    {
        return (objectType == typeof(Guid));
    }

    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        Guid guid = (Guid)value;
        writer.WriteStartObject();
        writer.WritePropertyName("Guid");
        writer.WriteValue(value.ToString());
        writer.WriteEndObject();
    }

    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        JObject jo = JObject.Load(reader);
        Guid guid = Guid.Parse(jo["Guid"].ToObject<string>());
        return guid;
    }
}

SerializerSettings = new JsonSerializerSettings
        {
            TypeNameHandling = TypeNameHandling.All,
            PreserveReferencesHandling = PreserveReferencesHandling.All,
            DateFormatHandling = DateFormatHandling.IsoDateFormat,
            DefaultValueHandling = DefaultValueHandling.Ignore,
            MissingMemberHandling = MissingMemberHandling.Ignore,
            NullValueHandling = NullValueHandling.Ignore,
            ConstructorHandling = ConstructorHandling.AllowNonPublicDefaultConstructor
        };

SerializerSettings.Converters.Add(new GuidConverter ());
JsonConvert.DeserializeObject(jsonString, SerializerSettings);

But it did not work.

[centur]

Is there any chance that this issue can be addressed and fixed or @JamesNK can take a look on the code above with custom converters and explain why it didn't work

[JamesNK]

It's by design. Include type information for every primitive value would create a mess.

I'm guessing the converter didn't work because when there is no type data then objectType will be System.Object and this won't pass:

    public override bool CanConvert(Type objectType)
    {
        return (objectType == typeof(Guid));
    }