Optional type, different argument for function in encode and decode

[Zehir]

Hello,

For some reason I get different params format when encoding and decoding data.

For example;

data: new r.Optional(new r.String('size', 'utf8'), (parent) => {
  console.log(parent)
  return !isBinaryType(parent.val?.type ?? parent.type)
}),

When encoding I get :

But when decoding I get :

So when I decoding I get the .val that I get in encoding

I that expected ?