import org.junit.Test
import javax.script.ScriptEngineManager
import kotlin.test.assertEquals

class ScriptTest {

@Test
fun testSimpleEval() {
    val engine = ScriptEngineManager().getEngineByExtension("kts")!!
    val res = engine.eval("2+4")
    assertEquals(6,res)
}

@Test
fun testSimpleBinding() {
    val engine = ScriptEngineManager().getEngineByExtension("kts")!!
    engine.put("hello","world")
    val res = engine.eval("hello")
    assertEquals("world",res)
}

}

I've got

javax.script.ScriptException: Unresolved reference: hello
at org.jetbrains.kotlin.cli.common.repl.KotlinJsr223JvmScriptEngineBase.compileAndEval(KotlinJsr223JvmScriptEngineBase.kt:65)
at org.jetbrains.kotlin.cli.common.repl.KotlinJsr223JvmScriptEngineBase.eval(KotlinJsr223JvmScriptEngineBase.kt:31)