Catch exception in Play 2 Test + Futures

how do I catch an exception inside a future success using play to test?

Here is my code:

"A Validity" should {
    "be created based on Client's Mobile" in new WithApplication {
      val objectId = UUIDs.timeBased()
      CValidityServiceModule.checkValidity(true, "MOBILE", clientId, objectId)
      val future = genericService.findByObjectIdAndByClientId(objectId, clientId)

      future.onComplete {
        case Success(s) => {
          s match {
            case Some(v) => {
              v.clientId mustEqual clientId
              v.objectId mustEqual objectId
            }
            case None => assert(false)
          }
        }
        case Failure(t) => {
          assert(false, t.getMessage)
        }
      }
    }

Basically if any matcher fail, it trows me an exception, but the test is green.

Any idea?