Behavior of zip

[soujiro32167]

After using Circe, I expected zip to behave like product:

import zio.json._

case class A(a: Int)
object A {
    implicit val codec: JsonCodec[A] = DeriveJsonCodec.gen
}

case class B(b: Int)
object B {
    implicit val codec: JsonCodec[B] = DeriveJsonCodec.gen
}

implicit val product: JsonDecoder[(A, B)] = JsonDecoder[A] <*> JsonDecoder[B]

"""
{"a":1,"b":2}
""".fromJson[(A, B)]

However, the implementation expects an array. This makes sense as a default, but how can I define the behavior above?

[soujiro32167]

related: #516

[pjoneswork]

I've hit this too. I think we need an implementation of zipWith that looks like:

    def newZipWith[B, C](other: JsonDecoder[B])(f: (A, B) => C): JsonDecoder[C] =
      new JsonDecoder[C] {
        def unsafeDecode(trace: List[JsonError], in: RetractReader): C = {
          // Can't actually do this in my code because it's private
          // And can't make my own RetractReader because it's a sealed trait
          val in2 = new zio.json.internal.WithRecordingReader(in) 
          val a = self.unsafeDecode(trace, in2)
          in2.rewind()
          val b = other.unsafeDecode(trace, in2)
          f(a, b)
        }
      }

[plokhotnyuk]

Fixed by #1260