Merge pull request #608 from Dwolla/resource-acquisition-exception

Tweak Specs2 CatsResource to rethrow exceptions raised during resource acquisition

Author: djspiewak

specs2/shared/src/main/scala/cats/effect/testing/specs2/CatsResource.scala

@@ -17,9 +17,9 @@
 package cats.effect.testing
 package specs2
 
-import cats.effect.{Async, Deferred, Resource, Spawn, Sync}
+import cats.effect._
+import cats.effect.syntax.all._
 import cats.syntax.all._
-
 import org.specs2.specification.BeforeAfterAll
 
 import scala.concurrent.duration._
@@ -39,7 +39,7 @@ abstract class CatsResource[F[_]: Async: UnsafeRun, A] extends BeforeAfterAll wi
   // but it does work on scalajs
   @volatile
   private var gate: Option[Deferred[F, Unit]] = None
-  private var value: Option[A] = None
+  private var value: Option[Either[Throwable, A]] = None
   private var shutdown: F[Unit] = ().pure[F]
 
   override def beforeAll(): Unit = {
@@ -49,7 +49,7 @@ abstract class CatsResource[F[_]: Async: UnsafeRun, A] extends BeforeAfterAll wi
         gate = Some(d)
       }
 
-      pair <- resource.allocated
+      pair <- resource.attempt.allocated
       (a, shutdownAction) = pair
 
       _ <- Sync[F] delay {
@@ -75,7 +75,7 @@ abstract class CatsResource[F[_]: Async: UnsafeRun, A] extends BeforeAfterAll wi
   def withResource[R](f: A => F[R]): F[R] =
     gate match {
       case Some(g) =>
-        g.get *> Sync[F].delay(value.get).flatMap(f)
+        finiteResourceTimeout.foldl(g.get)(_.timeout(_)) *> Sync[F].delay(value.get).rethrow.flatMap(f)
 
       // specs2's runtime should prevent this case
       case None =>

specs2/shared/src/test/scala/cats/effect/testing/specs2/CatsResourceErrorSpecs.scala

@@ -0,0 +1,43 @@
+/*
+ * Copyright 2020 Typelevel
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package cats.effect.testing.specs2
+
+import cats.effect.{IO, Resource}
+import org.specs2.execute.Result
+import org.specs2.mutable.SpecificationLike
+
+case class BlowUpResourceException() extends RuntimeException("boom")
+
+class CatsResourceErrorSpecs
+  extends CatsResource[IO, Unit]
+    with SpecificationLike {
+
+  private val expectedException = BlowUpResourceException()
+
+  val resource: Resource[IO, Unit] =
+    Resource.eval(IO.raiseError(expectedException))
+
+  "cats resource support" should {
+    "report failure when the resource acquisition fails" in withResource[Result] { _ =>
+      IO(failure("we shouldn't get here if an exception was raised"))
+    }
+      .recover[Result] {
+        case ex: RuntimeException =>
+          ex must beEqualTo(expectedException)
+      }
+  }
+}