Interesting approach.
Also another approach would be to add it after the Spec

object MutableRunnableSpecSpec extends MutableRunnableSpec(Ref.make(0).toLayer) {
  ...
} @@ sequential @@ before(ZIO.service[Ref[Int]].flatMap(_.update(_ + 1)))

topSuite looks better to me than this or aspects in constructor.

I think the most discoverable option might be a constructor parameter, e.g.:

... extends MutableRunnableSpec(myLayer, myAspects) { 
}

Ping @adamgfraser

Constructor parameters have limitation - cannot use methods from same spec object. They are useful for complex aspects like before or after

I'm inclined to think the constructor argument is the way to go as well. Seems more discoverable and you could always factor out the definition of the aspects and any common functionality you wanted to reference into another object.

@adamgfraser I updated PR to use constructor argument

Can you merge upstream changes so the new CI triggers?

@adamgfraser Done