Fix #42 - Futures created by async are not properly completed with exceptions

This augments the on-complete handler for an async state with await as follows:

    if (tr.isFailure)
      result$async.complete(tr.asInstanceOf[Try[T]])
    else {
      <resultName> = tr.get.asInstanceOf[<resultType>]
      <nextState>
      <mkResumeApply>
    }

1 files changed, 39 insertions, 0 deletions

diff --git a/src/test/scala/scala/async/run/exceptions/ExceptionsSpec.scala b/src/test/scala/scala/async/run/exceptions/ExceptionsSpec.scala
new file mode 100644
index 0000000..6f9e4ec
--- /dev/null
+++ b/src/test/scala/scala/async/run/exceptions/ExceptionsSpec.scala
@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) 2012 Typesafe Inc. <http://www.typesafe.com>
+ */
+
+package scala.async
+package run
+package exceptions
+
+import scala.async.Async.{async, await}
+
+import scala.concurrent.{future, ExecutionContext, Await}
+import ExecutionContext.Implicits._
+import scala.concurrent.duration._
+import scala.reflect.ClassTag
+
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.junit.runners.JUnit4
+
+@RunWith(classOf[JUnit4])
+class ExceptionsSpec {
+
+  @Test
+  def `complete future with exception`() {
+    val future0 = future[Any] {
+      "five!".length
+    }
+
+    val future2 = async {
+      val a = await(future0.mapTo[Int])                       // result: 5
+      val b = await((future { (a * 2).toString }).mapTo[Int]) // result: 10
+      val c = await(future { (7 * 2).toString })              // result: "14"
+      b + "-" + c
+    }
+
+    intercept[ClassCastException] { Await.result(future2, 5.seconds) }
+  }
+
+}