toFuture.scala

/**
 * queryStringをFakeRequestに入れるユーティリティ
 * FakeRequest().copy(queryString = qs)にすると、戻り値が
 * Iteratee[Array[Byte], Result] となるため、これを Future[B] へ fold します
 * 
 * //usage:
 * //    val actual = controller.purchase()(FakeRequest().copy( 
 * //     queryString = validBuyingRequestParams)) fold toFuture
 */
def toFuture[B](step: Step[Array[Byte], B]): Future[B] = step match {
  case Step.Done(a0, e) => Future(a0)
  case Step.Cont(k) => k(Input.EOF) fold {
    case Step.Done(a1, _) => Future.successful(a1)
    case _ => throw new Exception("error or diverging iteratee")
  }
  case Step.Error(msg, e) => throw new Exception("error iteratee")
}