Retry logic

[dalegaspi]

hello.

I ran into this issue when retry attempts == 1...the failAction is not being triggered and then i reviewed the code:

def retry[T](maxRetries: Option[Int],
               interval: Duration = DefaultInterval,
               backoff: Backoff = exponentialBackoff,
               failAction: Throwable => Unit = doNothing)
              (f: => Try[T]): Try[T] = {
    @tailrec
    def loop(retry: Int): Try[T] = f match {
      case s @ Success(_) => s
      case Failure(e) if maxRetries.forall(_ > retry) =>
        failAction(e)
        sleep(backoff(retry, interval))
        loop(retry + 1)
      case fail => fail
    }
    loop(1)
  }

i think the failAction should always trigger for a Failure even if maxRetries == 1. it should read like:

def retry[T](maxRetries: Option[Int],
               interval: Duration = DefaultInterval,
               backoff: Backoff = exponentialBackoff,
               failAction: Throwable => Unit = doNothing)
              (f: => Try[T]): Try[T] = {
    @tailrec
    def loop(retry: Int): Try[T] = f match {
      case s @ Success(_) => s
      case Failure(e) =>
        failAction(e) // call the callback
        if maxRetries.forall(_ > retry) {
          sleep(backoff(retry, interval))
          loop(retry + 1)
        }
      case fail => fail
    }
    loop(1)
  }