Stack overflow on 0.14.6

[GalLaloucheSqream]

Minimal reproduction steps:

import scala.annotation.tailrec
import io.circe.generic.auto._
import io.circe.syntax._

object CirceExample {
  case class Node(test: Vector[Node])
  @tailrec def go(maxSize: Int, result: Node): Node =
    if (maxSize == 0) result else go(maxSize - 1, Node(Vector(result)))
  def main(args: Array[String]): Unit =
    go(1000, Node(Vector.empty)).asJson: Unit
}

Running on Scala 2.13.10, and JDK 17.0.5.

[zarthross]

What scala versions please?

[GalLaloucheSqream]

What scala versions please?

I've updated the ticket with the Scala and Java version I've used.

[MartinHH]

In Scala 3, the example code does not compile, but if one adds derives Codec.AsObject as follows, the behavior is the same (Stack Overflow):

//> using scala "3.3.1"
//> using jvm "17"

//> using dep "io.circe::circe-generic::0.14.6"

import scala.annotation.tailrec
import io.circe.generic.auto._
import io.circe.syntax._

object CirceExample {
  case class Node(test: Vector[Node]) derives io.circe.Codec.AsObject
  @tailrec def go(maxSize: Int, result: Node): Node =
    if (maxSize == 0) result else go(maxSize - 1, Node(Vector(result)))
  def main(args: Array[String]): Unit =
    go(1000, Node(Vector.empty)).asJson: Unit
}

(Furthermore: this is not specific to 0.14.6.)

[plokhotnyuk]

@GalLaloucheSqream @MartinHH --java-opt -Xss4m should help for your samples

Even jsoniter-scala generates recursive calls for recursive data structures minimizing a stack depth to one call per one JSON level of nesting ({ or [).

A custom codec is required to transform recursive data structure into io.circe.Json using a heap-based stack and a while (tailrec) loop