I'm creating a Node.js api using Typebox, and I'm struggling with some types, specifically Dates and ObjectIds. I created a Transform for IsoDates and ObjectIds using the following...

export const TypeboxIsoDate = Type.Transform(Type.String({ format: 'date-time' }))
  .Decode(value => new Date(value))
  .Encode(value => value.toISOString());

export const TypeboxObjectId = Type.Transform(Type.String({ format: 'objectId' }))
  .Decode(value => {
    // When coming from string (like JSON), convert to ObjectId
    // For TypeBox transformers, value should always be a string during Decode
    return new ObjectId(value as string);
  })
  .Encode(value => {
    // When serializing, convert ObjectId to string
    // Handle the case where value might already be a string
    if (typeof value === 'string') return value;
    // Use toString() for ObjectId or any object with toString method
    return (value as any).toString();;
  });

Here is my schema definition for a product...

export const ProductSchema = Type.Object({
  _id: TypeboxObjectId,
  name: Type.String({
    title: 'Name'
  }),
  description: Type.Optional(Type.String({
    title: 'Description'
  })),
  price: Money({
    minimum: 0,
    title: 'Price'
  }),
  quantity: Type.Number({
    minimum: 0,
    title: 'Quantity'
  }),
  someDate: TypeboxIsoDate
});

When I post the following json to the POST of my /products endpoint...

{
    "name": "Widget",
    "description": "It is a Widget",
    "price": 39.99,
    "quantity": 7,
    "someDate": "2025-03-25T18:18:56.000Z"
}

This is what gets returned in the response...

{
        "name": "Widget",
        "description": "It is a Widget",
        "price": 39.99,
        "quantity": 7,
        "someDate": "2025-03-25T18:18:56.000Z",
        "_id": {
            "buffer": {
                "type": "Buffer",
                "data": [
                    103,
                    234,
                    201,
                    39,
                    112,
                    235,
                    139,
                    42,
                    63,
                    1,
                    179,
                    14
                ]
            }
        },
        "_created": "2025-03-31T16:56:07.040Z",
        "_createdBy": "system",
        "_updated": "2025-03-31T16:56:07.040Z",
        "_updatedBy": "system"
    }

So... that _id is really weird, but it seems to be ok in MongoDb. Also, in MongoDb, someDate is just a string, but _created and _updated are actual ISODates. I auto-created those fields as Dates before saving, but the incoming someDate property never gets converted to an actual Date. Here is what the document looks like in MongoDb...

{
    "_id" : ObjectId("67eac843bc800a699734da58"),
    "name" : "Doohicky",
    "description" : "It is a Doohicky",
    "price" : 39.99,
    "quantity" : NumberInt(7),
    "someDate" : "2025-03-25T18:18:56.000Z",
    "_created" : ISODate("2025-03-31T16:52:19.792+0000"),
    "_createdBy" : "system",
    "_updated" : ISODate("2025-03-31T16:52:19.792+0000"),
    "_updatedBy" : "system"
}

What I want is for these fields to generate actual ObjectIds and ISODates in Mongodb, ObjectIds and Dates in javascript, and also generate proper json-schema - { "type": "string", "format": "objectId" } and { "type": "string", "format": "date-time" }, respectively. I'm actually not sure about that json-schema for ObjectId, but I am very sure about the json-schema for date-time.

Any help will be greatly appreciated.