Can not serialize/deserialize type with "internal" or "private" modifier

Hello. When I try to serialize/deserialize Person, I have an exception

FSharp.Json.JsonSerializationError: ‘Failed to serialize, must be one of following types: record, map, array, list, tuple, union. Type is: Person.’

But if I remove internal modifier for Person, the code works fine

type internal Person = {

    [<JsonField("name")>]
    Name: string

    [<JsonField("age")>]
    Age: int
}

[<EntryPoint>]
let main argv =
    let person = { Name = "John"; Age = 42 }
    let json = Json.serialize person
    0

[bzuu-ic]

I am mostly thinking along the lines of adding this as a configuration option which can be used with the serializeEx and deserializeEx methods. This allows you to use it only in those circumstances where you actually need it and it makes it a very deliberate choice. For all other cases you can keep the more sensible default.

[bartelink]

I think this should not be the default behaviour indeed

I get that; I’ve been bitten by it too, and it is can be very frustrating, but the fact that this would place this lib on its own in terms of opting people into the cost of private reflection.

Flipping a default like this can be considered a breaking change, depending on how you look at it.

(Its also possible that there’s been perf optimization work done to special case the loading such that you only pay extra cost when they are private - that would probably be something that people would be less surprised by, if it were the case…)