如何在收集验证错误时将转换应用于json数组中的所有元素？

Question

给定一个json数组和要在每个元素上使用的转换 - 如何在收集验证错误时将转换应用于所有元素？

scenario("pick attributes") {

  Given("a json array and a transformation to be used on each element")
  val jsonArray = Json.arr(
    Json.obj("a" -> Json.obj("b" -> 1), "b" -> 2),
    Json.obj("a" -> 2, "b" -> 4),
    Json.obj("a" -> 3, "b" -> 6)
  )
  info(Json.stringify(jsonArray))
  val elementTrans = (__ \ "b").json.update(__.read[Int] map { n => JsArray(Seq(JsNumber(n), JsNumber(n*2)))})

  When("we do this (read a seq, map its elements to their transformed values, turn it into json again)")
  //I lose the errors this way - what's a way to transform the whole thing and collect all errors?
  val read = __.read[Seq[JsValue]] map { value =>
    Json.toJson(
      value.map { e =>
        info("e: " + e)
        e.transform(elementTrans).get
      }
    )
  }

  Then("the transformation took place on every single element")
  jsonArray.validate(read).fold(
    invalid = seq => fail(errorSequenceToString("invalid: ", seq)),
    valid = a => info("valid: " + Json.stringify(a))
  )
}

Answer 1

您可以map然后使用partition将结果分为两类：失败的和失败的。