Scala Issue with Mixin Traits and Conflicting Members

Question

I have the following setup for ms Scala test where I have a trait that looks like this:

trait CPODBTestContainerSpec extends AnyFlatSpecLike with TestContainerForAll {

  ....
  ....
}

abstract class BaseCPOControllerSpec extends PlaySpec with Results with FakeApplicationFactory with CPODBTestContainerSpec {

  ....
  ....
}

When I tried to run it, I get the following error message. I clearly understand what it states, but I'm not sure how I could fix this. These two traits above do different things and I need both of them in my scope.

class BaseCPOControllerSpec inherits conflicting members:
  protected def info: org.scalatest.Informer (defined in trait AnyWordSpecLike) and
  protected def info: org.scalatest.Informer (defined in trait AnyFlatSpecLike)
  (note: this can be resolved by declaring an `override` in class BaseCPOControllerSpec.);
 other members with override errors are: note, alert, markup, registerTest, registerIgnoredTest, it, they, behave, styleName
abstract class BaseCPOControllerSpec extends PlaySpec with Results with FakeApplicationFactory with CPODBTestContainerSpec {

I learnt about trait linearization, but not sure if I can fix this by restructuring my traits?

Answer 1

The conflict comes from the fact that the hierarchy of traits you want to use is mixing:

• AnyFlatSpecLike from your own CPODBTestContainerSpec
• AnyWordSpecLike from PlaySpec

These are two different ways of writing tests with Scalatest. It doesn't make sense to want to use both.

If you need the PlaySpec, I would change CPODBTestContainerSpec to extends AnyWordSpecLike.