Beautiful validation with scalaz. Fail fast in the for-comprehension and fail slow with the application builder

gistfile1.scala

def editResult(testId: LabOnlineId[Test], worklistId: LabOnlineId[Worklist], result: TestResult): Future[ActionResult] =
  for {
    test <- ensureExists(testId)(testData.findOne(_))
    sample <- ensureExists(test._sampleId)(sampleData.findOneWithWorklist(_, worklistId))
  } yield {
    (ensureNotClosed(sample, worklistId) |@|
     ensureNotClosed(test, worklistId))((_,_)) match {
       case Failure(errors) => ActionResult.UserError(errors.toList: _*)
       case Success(_) => /* run a stored procedure */ ActionResult.Ok
     }
  }