DU deserialize with chiron

duChiron.fs

type EventOne =
    { Property: string }
     static member FromJson(_: EventOne) =
        json {
            let! p = Json.read "property"
            return {Property = p}
        }
type EventTwo =
    { Property: int }
    static member FromJson(_: EventTwo) =
          json {
            let! p = Json.read "property"
            return {Property = p}
          }

type Event =
    | One of EventOne
    | Two of EventTwo
    

type Test1 =
    { Data: Event
      EventType: string }

    static member FromJson(_: Test1) =
        json {
            let! eventType = Json.read "eventType"

            let! data =
                match eventType with
                | "one" -> 
                    json {
                        let! e = Json.read "data" 
                        return e|> One
                    }
                | "two" -> 
                    json{
                         let! e = Json.read "data"
                         return e|> Two
                    } 
                | _ -> failwith "Not supported"
            return { 
                        Data = data
                        EventType = eventType 
                    }
        }

let js = """
{
        "eventType": "one",
        "data": {
            "property": "ABC"
        }
}
"""

[<Fact>]
let asdf () =
    Json.parse js
    |> Json.deserialize =! 
        {
            Data = One ({Property="ABC"})
            EventType = "one"
        }