Merge pull request http4s/http4s#4160 from yanns/shutdown_dispatcher

shutdown dispatcher

testing/src/test/scala/org/http4s/testing/DispatcherIOFixture.scala

@@ -0,0 +1,40 @@
+/*
+ * Copyright 2016 http4s.org
+ *
+ * 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 org.http4s.testing
+
+import cats.effect.IO
+import cats.effect.std.Dispatcher
+import org.http4s.Http4sSuite
+
+trait DispatcherIOFixture { this: Http4sSuite =>
+
+  val dispatcher: Fixture[Dispatcher[IO]] = new Fixture[Dispatcher[IO]]("dispatcher") {
+    var dispatcher: Dispatcher[IO] = _
+    var shutdown: IO[Unit] = _
+    override def apply(): Dispatcher[IO] = dispatcher
+
+    override def beforeAll(): Unit = {
+      val dispatcherAndShutdown = Dispatcher[IO].allocated.unsafeRunSync()
+      dispatcher = dispatcherAndShutdown._1
+      shutdown = dispatcherAndShutdown._2
+    }
+
+    override def afterAll(): Unit =
+      shutdown.unsafeRunSync()
+  }
+
+}