Instead of having a separate runner class for this, it would be easier to create an action within the spec you're testing, run the action, and have the action put its context classloader into a promise so that the main part of the test can check it.

````scala
val actualClassLoader = Promise[ClassLoader]()
val action: EssentialAction = Action {
  actualClassLoader.set(Thread.currentThread.getContextClassLoader)
  Ok("")
}
... run action
Await.result(actualClassLoader.future) mustEqual expectedClassLoader
````