Gatling - Dynamic Scenario, InjectionProfile, Assertion creation based on Configuration

I am attempting to write a simulation that can read from a config file for a set of apis that each have a set of properties.

• I read the config for n active scenarios and create requests from a CommonRequest class
• Then those requests are built into scenarios from a CommonScenario
• CommonScenarios have attributes that are using to create their injection profiles

That all seems to work no issue. But when I try to use the properties / CommonScenario request to build a set of Assertions it does not work as expected.

  // get active scenarios from the config
val activeApiScenarios: List[String] = Utils.getStringListProperty("my.active_scenarios")
// build all active scenarios from config
var activeScenarios: Set[CommonScenario] = Set[CommonScenario]()
activeApiScenarios.foreach { scenario =>
activeScenarios += CommonScenarioBuilder()
.withRequestName(Utils.getProperty("my." + scenario + ".request_name"))
.withRegion(Utils.getProperty("my." + scenario + ".region"))
.withConstQps(Utils.getDoubleProperty("my." + scenario + ".const_qps"))
.withStartQps(Utils.getDoubleListProperty("my." + scenario + ".toth_qps").head)
.withPeakQps(Utils.getDoubleListProperty("my." + scenario + ".toth_qps")(1))
.withEndQps(Utils.getDoubleListProperty("my." + scenario + ".toth_qps")(2))
.withFeeder(Utils.getProperty("my." + scenario + ".feeder"))
.withAssertionP99(Utils.getDoubleProperty("my." + scenario + ".p99_lte_assertion"))
.build
}
// build population builder set by adding inject profile values to scenarios
var injectScenarios: Set[PopulationBuilder] = Set[PopulationBuilder]()
var assertions : Set[Assertion] = Set[Assertion]()
activeScenarios.foreach { scenario =>
// create injection profiles from CommonScenarios
injectScenarios += scenario.getCommonScenarioBuilder
.inject(nothingFor(5 seconds),
rampUsersPerSec(scenario.startQps).to(scenario.rampUpQps).during(rampOne seconds),
rampUsersPerSec(scenario.rampUpQps).to(scenario.peakQps).during(rampTwo seconds),
rampUsersPerSec(scenario.peakQps).to(scenario.rampDownQps) during (rampTwo seconds),
rampUsersPerSec(scenario.rampDownQps).to(scenario.endQps).during(rampOne     seconds)).protocols(httpProtocol)
// create scenario assertions this does not work for some reason
assertions += Assertion(Details(List(scenario.requestName)), TimeTarget(ResponseTime, Percentiles(4)), Lte(scenario.assertionP99))
}
setUp(injectScenarios.toList)
.assertions(assertions)

Note scenario.requestName is straight from the build scenario

    .feed(feederBuilder)
.exec(commonRequest)

I would expect the Assertions get built from their scenarios into an iterable and pass into setUp().

What I get:

When I print out everything the scenarios, injects all look good but then I print my "assertions" and get 4 assertions for the same scenario name with 4 different Lte() values. This is generalized but I configured 12 apis all with different names and Lte() values, etc.

Details(List(Request Name)) - TimeTarget(ResponseTime,Percentiles(4.0)) - Lte(500.0)
Details(List(Request Name)) - TimeTarget(ResponseTime,Percentiles(4.0)) - Lte(1500.0)
Details(List(Request Name)) - TimeTarget(ResponseTime,Percentiles(4.0)) - Lte(1000.0)
Details(List(Request Name)) - TimeTarget(ResponseTime,Percentiles(4.0)) - Lte(2000.0)

After the simulation the assertions all run like normal:

Request Name: 4th percentile of response time is less than or equal to 500.0 : false
Request Name: 4th percentile of response time is less than or equal to 1500.0 : false
Request Name: 4th percentile of response time is less than or equal to 1000.0 : false
Request Name: 4th percentile of response time is less than or equal to 2000.0 : false

Not sure what I am doing wrong when building my assertions. Is this even a valid approach? I wanted to ask for help before I abandon this for a different approach.

Disclaimer: Gatling creator here.

It should work.

Then, there are several things I'm super not found of.

> assertions += Assertion(Details(List(scenario.requestName)), TimeTarget(ResponseTime, Percentiles(4)), Lte(scenario.assertionP99))

You shouldn't be using the internal AST here. You should use the DSL like you've done for the injection profile.

> var assertions : Set[Assertion] = SetAssertion
>
> activeScenarios.foreach { scenario =>

You should use map on activeScenarios (similar to Java's Stream API), not use a mutable accumulator.

val activeScenarios = activeApiScenarios.map(???)
val injectScenarios = activeScenarios.map(???)
val assertions = activeScenarios.map(???)

Also, as you seem to not be familiar with Scala, you should maybe switch to Java (supported for more than 1 year).