Scala JSR223 script using JMeter/Java context

The core of the issue is that injected bindings are seen by the Scala script engine as having a type of Any. To use the injected bindings you either have to cast them to the appropriate type on every use, or you need to inject them as a 'shadow binding' and then re-bind in-engine using the appropriate type.

Here is my Main.scala, where I demonstrate the latter approach:

import javax.script.ScriptEngineManager

import org.slf4j.Logger
import org.slf4j.LoggerFactory

object Main extends App {

  val logger: Logger = LoggerFactory.getLogger("main")

  val e = new ScriptEngineManager().getEngineByName("scala")
  e.put("a", 1)
  e.put("s", "String")

  // Since the variable will have a type of Object, inject under a different name, and then bind to the
  // "correct" name using eval.
  e.put("logInjected", logger)

  println(e.eval(""" s"a is $a, s is $s" """))
  println(e.eval(""" logInjected.toString """))

  e.eval(""" val log = logInjected.asInstanceOf[org.slf4j.Logger] """)
  e.eval(""" log.info("hello from injected logger") """)

  e.eval(
    """ // Or can you do this
      | import org.slf4j.Logger
      | import org.slf4j.LoggerFactory
      |
      | val l = LoggerFactory.getLogger("script")
      |
      | l.error("hello from script")
      |
      |""".stripMargin)
}

And my build.sbt I used to:

name := "s213"

version := "1.0"

scalaVersion in ThisBuild := "2.13.0"

libraryDependencies += "org.scala-lang" % "scala-compiler" % scalaVersion.value
libraryDependencies += "org.scala-lang" % "scala-reflect" % scalaVersion.value
libraryDependencies += "ch.qos.logback" % "logback-classic" % "1.3.0-alpha4"
libraryDependencies += "org.slf4j" % "slf4j-api" % "2.0.0-alpha0"

The output from running Main will be:

a is 1, s is String
Logger[main]
[main] INFO  main - hello from injected logger 
[main] ERROR script - hello from script