Gatling: transform findAll to sorted list

Question

I'm new to scala and Gatling. I'm trying to transform the result of findAll into a sorted list and then return a String representation of the sorted list. I can't seem to do this with the following code:

http(requestTitle)
  .post(serverUrl)
  .body(ElFileBody(sendMessageFile))
  .header("correlation-id", correlationId)
  .check(status.is(200),
    jsonPath("$.data.sendMessage.targetedRecipients").findAll.transform(recipients => {
      println("recipients class: " + recipients.getClass)
      var mutable = scala.collection.mutable.ListBuffer(recipients: _*)
      var sortedRecipients = mutable.sortWith(_ < _)
      println("users sorted "+ usersSorted)
      usersSorted.mkString(",")
  }).is(expectedMessageRecipients))

Recipients is of type scala.collection.immutable.Vector. I thought I would be able to convert the immutable collection into a mutable collection using scala.collection.mutable.ListBuffer. Any help would be appreciated, thanks.

Answer 1

I don't think your problem is immutability, it's JSON parsing vs Gatling's .find and .findAll methods.

I'm going to make a guess that your response looks something like...

{"data":{"sendMessage":{"targetedRecipients":[1,4,2,3]}}}

in which case Gatling's .findAll method will return a vector (it always does if it finds something), but it will only have one element which will be "[1,4,2,3]" - ie: a string representing json data, so sorting the collection of a single element naturally achieves nothing. To get .findAll to behave like you seem to be expecting, you would need a response something like...

{"data":
 {"sendMessage":
  {"targetedRecipients":
    [{"recipientId":1},
     {"recipientId":4},
     {"recipientId":2},
     {"recipientId":3}]
 }}}

which you could use .jsonPath("$..recipientId").findAllto turn into a Vector[String] of the Ids.

So assuming you are indeed just getting a single string representation of an array of values, you could use a straight transform to generate an array and sort (as you tried in your example)

Here's a working version

val data = """{"data":{"sendMessage":{"targetedRecipients":[1,4,2,3]}}}"""

def sortedArray : ScenarioBuilder = scenario("sorting an array")
.exec(http("test call")
.post("http://httpbin.org/anything")
.body(StringBody(data)).asJson
.check(
  status.is(200),
  jsonPath("$.json.data.sendMessage.targetedRecipients")
    .find
    .transform(_
      .drop(1)
      .dropRight(1)
      .split(",")
      .toVector
      .sortWith(_<_)
    )
    .saveAs("received")
))
.exec(session => {
  println(s"received: ${session("received").as[Vector[String]]}")
  session
})