Using Akka TestKit with Specs2

Question

I'm trying to craft a specs2 test using Akka's TestKit. I'm stuck on a persistent compile error I can't figure out how to resolve, and I'd appreciate suggestions.

The compile error is:

TaskSpec.scala:40: parents of traits may not have parameters
[error]   with akka.testkit.TestKit( ActorSystem( "testsystem", ConfigFactory.parseString( TaskSpec.config ) ) )

Following suggestions from Akka docs and internet xebia and Akka in Action, I'm trying to incorporate the TestKit into a specs2 Scope. Here's a snippet of the code where I'm getting the error:

class TaskSpec 
extends Specification 
with AsyncTest
with NoTimeConversions { 

  sequential 

  trait scope 
  extends Scope 
  with TestKit( ActorSystem( "testsystem", ConfigFactory.parseString( TaskSpec.config ) ) ) 
  with AkkaTestSupport {
...

I have the following helper:

trait AkkaTestSupport extends After { outer: TestKit =>
  override protected def after: Unit = {
    system.shutdown()
    super.after
  }
}

score 6 · Accepted Answer · answered Nov 12 '13 at 00:38

6

Here is one thing you can do:

import org.specs2.mutable.SpecificationLike
import org.specs2.specification._

class TestSpec extends Actors { isolated
  "test1" >> ok
  "test2" >> ok
}

abstract class Actors extends 
 TestKit(ActorSystem("testsystem", ConfigFactory.parseString(TaskSpec.config)))
 with SpecificationLike with AfterExample {

  override def map(fs: =>Fragments) = super.map(fs) ^ step(system.shutdown, global = true)

  def after = system.shutdown
}

This should avoid the compilation error you had because TestKit is an abstract class and it is only mixing-in traits: SpecificationLike is a trait (Specification isn't) and AfterExample is a trait.

Also the specification above runs in the isolated mode, meaning that there is a brand new TestSpec object instantiated for each example and the AfterExample trait makes sure that the system is shutdown after each example.

Finally the map method is overriden with a special step to make sure that the system created for the first TestSpec instance (the one declaring all the examples) will be cleanly disposed of.

answered Nov 12 '13 at 00:38

Eric

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Thanks for this insight. I ended up resolving the issue by changing the scope to be a class (missed that), but I am playing with this structure. – dr. Nov 12 '13 at 20:56
Thanks Eric. What is the global=true parameter in the step you specified above? – Leo Apr 20 '14 at 00:23
An `isolated` spec means that each example is executed in its own copy of the specification class and all the steps preceding the examples are also executed (because they might be important to setup the context). Except if they are marked as `global` and, in this case, they are executed only once for the whole specification. – Eric Apr 20 '14 at 12:28
Updated solution at https://github.com/gangstead/specs2-akka-testkit-demo/blob/master/src/test/scala/MySpec.scala – Synesso Jun 26 '17 at 23:07

Using Akka TestKit with Specs2

1 Answers1