How can I parameterise information in Gatling scenarios - scala

Question

I need to send specific parameters to a scenario that is being reused multiple times with different payloads depending on the workflows. The following is the code that is to be reused:
var reqName = ""
var payloadName = ""
lazy val sendInfo: ScenarioBuilder = scenario("Send info")
.exec(session => {
reqName = session("localReqName").as[String]
payloadName = session("localPayloadName").as[String]
session}
)
.exec(jms(s"$reqName")
.send
.queue(simQueue)
.textMessage(ElFileBody(s"$payloadName.json"))
)
.exec(session => {
val filePath = s"$payloadName"
val body = new String(Files.readAllBytes(Paths.get(ClassLoader.getSystemResource(filePath).toURI)))
logger.info("timestamp value: " + session("timestamp").as[String])
logger.debug("Template body:\n " + body)
session
})
I know that you can chain scenarios in Scala/Gatling but how can I pass in information like reqName and payloadName down the chain, where reqName is a parameter to indicate the name of the request where the info is being sent and payloadName is the name of the actual JSON payload for the related request:
lazy val randomInfoSend: ScenarioBuilder = scenario("Send random info payloads")
.feed(csv("IDfile.csv").circular)
.randomSwitch(
(randomInfoType1prob) -> exec(
feed(timeFeeder)
.exec(session => {
payloadName = "Info1payload.json"
reqName ="Info1Send"
session.set("localReqName", "Info1Send")
session.set("localPayloadName", "Info1payload.json")
session
})
.exec(sendInfo)
),
(100.0 - randomInfoType1prob) -> exec(
feed(timeFeeder)
.exec(session => {
payloadName = "Info2Payload.json"
reqName ="Info2Send"
session.set("localReqName", "Info2Send")
session.set("localPayloadName", "Info2Payload.json")
session
})
.exec(sendInfo)
)
I attempted the above but the values of that 2 specific parameters were not passed through correctly. (The IDs and timestamps were fed through correctly though) Any suggestions?

Answer 1

Please properly read the Session API documentation. Session is immutable so Session#set returns a new instance.