import scala.concurrent._
import scala.concurrent.duration._
import scala.concurrent.duration.Duration.Inf
import scala.collection._
import scala.runtime.NonLocalReturnControl
import scala.util.{Try,Success,Failure}
class PromiseTests extends MinimalScalaTest {
import ExecutionContext.Implicits._
val defaultTimeout = Inf
/* promise specification */
"An empty Promise" should {
"not be completed" in {
val p = Promise()
p.future.isCompleted mustBe (false)
p.isCompleted mustBe (false)
}
"have no value" in {
val p = Promise()
p.future.value mustBe (None)
p.isCompleted mustBe (false)
}
"return supplied value on timeout" in {
val failure = Promise.failed[String](new RuntimeException("br0ken")).future
val otherFailure = Promise.failed[String](new RuntimeException("last")).future
val empty = Promise[String]().future
val timedOut = Promise.successful[String]("Timedout").future
Await.result(failure fallbackTo timedOut, defaultTimeout) mustBe ("Timedout")
Await.result(timedOut fallbackTo empty, defaultTimeout) mustBe ("Timedout")
Await.result(otherFailure fallbackTo failure fallbackTo timedOut, defaultTimeout) mustBe ("Timedout")
intercept[RuntimeException] {
Await.result(failure fallbackTo otherFailure, defaultTimeout)
}.getMessage mustBe ("br0ken")
}
"be completable with a completed Promise" in {
{
val p = Promise[String]()
p.tryCompleteWith(Promise[String]().success("foo").future)
Await.result(p.future, defaultTimeout) mustBe ("foo")
}
{
val p = Promise[String]()
p.completeWith(Promise[String]().success("foo").future)
Await.result(p.future, defaultTimeout) mustBe ("foo")
}
{
val p = Promise[String]()
p.tryCompleteWith(Promise[String]().failure(new RuntimeException("br0ken")).future)
intercept[RuntimeException] {
Await.result(p.future, defaultTimeout)
}.getMessage mustBe ("br0ken")
}
{
val p = Promise[String]()
p.tryCompleteWith(Promise[String]().failure(new RuntimeException("br0ken")).future)
intercept[RuntimeException] {
Await.result(p.future, defaultTimeout)
}.getMessage mustBe ("br0ken")
}
}
}
"A successful Promise" should {
"be completed" in {
val result = "test value"
val promise = Promise[String]().complete(Success(result))
promise.isCompleted mustBe (true)
futureWithResult(_(promise.future, result))
}
"not be completable with a completed Promise" in {
{
val p = Promise.successful("bar")
p.tryCompleteWith(Promise[String]().success("foo").future)
Await.result(p.future, defaultTimeout) mustBe ("bar")
}
{
val p = Promise.successful("bar")
p.completeWith(Promise[String]().success("foo").future)
Await.result(p.future, defaultTimeout) mustBe ("bar")
}
}
}
"A failed Promise" should {
"be completed" in {
val message = "Expected Exception"
val promise = Promise[String]().complete(Failure(new RuntimeException(message)))
promise.isCompleted mustBe (true)
futureWithException[RuntimeException](_(promise.future, message))
}
"not be completable with a completed Promise" in {
{
val p = Promise[String]().failure(new RuntimeException("unbr0ken"))
p.tryCompleteWith(Promise[String].failure(new Exception("br0ken")).future)
intercept[RuntimeException] {
Await.result(p.future, defaultTimeout)
}.getMessage mustBe ("unbr0ken")
}
{
val p = Promise[String]().failure(new RuntimeException("unbr0ken"))
p.completeWith(Promise[String]().failure(new Exception("br0ken")).future)
intercept[RuntimeException] {
Await.result(p.future, defaultTimeout)
}.getMessage mustBe ("unbr0ken")
}
}
}
"An interrupted Promise" should {
val message = "Boxed InterruptedException"
val future = Promise[String]().complete(Failure(new InterruptedException(message))).future
futureWithException[ExecutionException](_(future, message))
}
"A NonLocalReturnControl failed Promise" should {
val result = "test value"
val future = Promise[String]().complete(Failure(new NonLocalReturnControl[String]("test", result))).future
futureWithResult(_(future, result))
}
def futureWithResult(f: ((Future[Any], Any) => Unit) => Unit) {
"be completed" in { f((future, _) => future.isCompleted mustBe (true)) }
"contain a value" in { f((future, result) => future.value mustBe (Some(Success(result)))) }
"return when ready with 'Await.ready'" in { f((future, result) => Await.ready(future, defaultTimeout).isCompleted mustBe (true)) }
"return result with 'Await.result'" in { f((future, result) => Await.result(future, defaultTimeout) mustBe (result)) }
"not timeout" in { f((future, _) => Await.ready(future, 0 millis)) }
"filter result" in {
f {
(future, result) =>
Await.result((future filter (_ => true)), defaultTimeout) mustBe (result)
intercept[NoSuchElementException] {
Await.result((future filter (_ => false)), defaultTimeout)
}
}
}
"transform result with map" in { f((future, result) => Await.result((future map (_.toString.length)), defaultTimeout) mustBe (result.toString.length)) }
"compose result with flatMap" in {
f { (future, result) =>
val r = for (r <- future; p <- Promise.successful("foo").future) yield r.toString + p
Await.result(r, defaultTimeout) mustBe (result.toString + "foo")
}
}
"perform action with foreach" in {
f {
(future, result) =>
val p = Promise[Any]()
future foreach p.success
Await.result(p.future, defaultTimeout) mustBe (result)
}
}
"zip properly" in {
f {
(future, result) =>
Await.result(future zip Promise.successful("foo").future, defaultTimeout) mustBe ((result, "foo"))
intercept[RuntimeException] {
Await.result(future zip Promise.failed(new RuntimeException("ohnoes")).future, defaultTimeout)
}.getMessage mustBe ("ohnoes")
}
}
"not recover from exception" in { f((future, result) => Await.result(future.recover({ case _ => "pigdog" }), defaultTimeout) mustBe (result)) }
"perform action on result" in {
f {
(future, result) =>
val p = Promise[Any]()
future.onSuccess { case x => p.success(x) }
Await.result(p.future, defaultTimeout) mustBe (result)
}
}
"not project a failure" in {
f {
(future, result) =>
intercept[NoSuchElementException] {
Await.result(future.failed, defaultTimeout)
}.getMessage mustBe ("Future.failed not completed with a throwable.")
}
}
"cast using mapTo" in {
f {
(future, result) =>
Await.result(future.mapTo[Boolean].recover({ case _: ClassCastException ⇒ false }), defaultTimeout) mustBe (false)
}
}
}
def futureWithException[E <: Throwable: Manifest](f: ((Future[Any], String) => Unit) => Unit) {
"be completed" in {
f((future, _) => future.isCompleted mustBe (true))
}
"contain a value" in {
f((future, message) => {
future.value.get.failed.get.getMessage mustBe (message)
})
}
"throw not throw exception with 'Await.ready'" in {
f {
(future, message) => Await.ready(future, defaultTimeout).isCompleted mustBe (true)
}
}
"throw exception with 'Await.result'" in {
f {
(future, message) =>
intercept[E] {
Await.result(future, defaultTimeout)
}.getMessage mustBe (message)
}
}
"retain exception with filter" in {
f {
(future, message) =>
intercept[E] { Await.result(future filter (_ => true), defaultTimeout) }.getMessage mustBe (message)
intercept[E] { Await.result(future filter (_ => false), defaultTimeout) }.getMessage mustBe (message)
}
}
"retain exception with map" in {
f {
(future, message) =>
intercept[E] { Await.result(future map (_.toString.length), defaultTimeout) }.getMessage mustBe (message)
}
}
"retain exception with flatMap" in {
f {
(future, message) =>
intercept[E] { Await.result(future flatMap (_ => Promise.successful("foo").future), defaultTimeout) }.getMessage mustBe (message)
}
}
"zip properly" in {
f {
(future, message) =>
intercept[E] {
Await.result(future zip Promise.successful("foo").future, defaultTimeout)
}.getMessage mustBe (message)
}
}
"recover from exception" in {
f {
(future, message) =>
Await.result(future.recover({ case e if e.getMessage == message ⇒ "pigdog" }), defaultTimeout) mustBe ("pigdog")
}
}
"project a failure" in {
f((future, message) => Await.result(future.failed, defaultTimeout).getMessage mustBe (message))
}
"perform action on exception" in {
f {
(future, message) =>
val p = Promise[Any]()
future.onFailure { case _ => p.success(message) }
Await.result(p.future, defaultTimeout) mustBe (message)
}
}
"always cast successfully using mapTo" in {
f {
(future, message) =>
intercept[E] { Await.result(future.mapTo[java.lang.Thread], defaultTimeout) }.getMessage mustBe (message)
}
}
}
}