如何在scala中更新嵌套的JSON数组

import play.api.libs.json._
import play.api.libs.json.Reads._
import play.api.libs.functional.syntax._

case class Person(name: String, age: Int)

implicit val personReads: Reads[Person] = (
  (JsPath \ "name").read[String] and
  (JsPath \ "age").read[Int]
)(Person.apply _)

implicit val personWrites: Writes[Person] = (
  (JsPath \ "name").write[String] and
  (JsPath \ "age").write[Int]
)(unlift(Person.unapply))

val jsonStr = """{
  "people": [
    {
      "name": "Alice",
      "age": 25
    },
    {
      "name": "Bob",
      "age": 30
    }
  ]
}"""

val json = Json.parse(jsonStr)

val updatedJson = json.transform((__ \ 'people).json.update(
  __.read[JsArray].map { case JsArray(arr) =>
    JsArray(arr :+ Json.toJson(Person("Charlie", 35)))
  }
)).get

val updatedJsonStr = Json.stringify(updatedJson)
println(updatedJsonStr)