zio-json-heterogenous-array.scala

//> using scala "3.2"
//> using lib "dev.zio::zio-json:0.3.0"

import zio.json.*
import zio.json.ast.Json

type T1 = (String, Int)
type T2 = (Int, String)

given JsonDecoder[T1 | T2] = 
  JsonDecoder[Json].mapOrFail(j => j.as[T1] orElse j.as[T2])

@main def main =
  val Right(lst) = """[[1, "a"], ["b", 2]]""".fromJson[List[T1 | T2]]: @unchecked
  
  assert { 
    lst == List((1, "a"), ("b", 2)) 
  }