Merge pull request #2554 from armanbilge/topic/node-server-tweaks

Improve Node.js server shutdown and error handling

Author: mpilquist

io/js/src/main/scala/fs2/io/net/SocketGroupPlatform.scala

@@ -33,6 +33,7 @@ import com.comcast.ip4s.Host
 import com.comcast.ip4s.IpAddress
 import com.comcast.ip4s.Port
 import com.comcast.ip4s.SocketAddress
+import fs2.internal.jsdeps.node.eventsMod
 import fs2.internal.jsdeps.node.netMod
 import fs2.internal.jsdeps.node.nodeStrings
 import fs2.internal.jsdeps.std
@@ -81,40 +82,38 @@ private[net] trait SocketGroupCompanionPlatform { self: SocketGroup.type =>
     ): Resource[F, (SocketAddress[IpAddress], Stream[F, Socket[F]])] =
       (for {
         dispatcher <- Dispatcher[F]
-        queue <- Queue.unbounded[F, netMod.Socket].toResource
-        error <- F.deferred[Throwable].toResource
+        queue <- Queue.unbounded[F, Option[netMod.Socket]].toResource
         server <- Resource.make(
           F
             .delay(
               netMod.createServer(
                 netMod.ServerOpts().setPauseOnConnect(true).setAllowHalfOpen(true),
-                sock => dispatcher.unsafeRunAndForget(queue.offer(sock))
+                sock => dispatcher.unsafeRunAndForget(queue.offer(Some(sock)))
               )
             )
         )(server =>
-          F.async_[Unit] { cb =>
+          F.async[Unit] { cb =>
             if (server.listening)
-              server.close(e => cb(e.toLeft(()).leftMap(js.JavaScriptException)))
+              F.delay(server.close(e => cb(e.toLeft(()).leftMap(js.JavaScriptException)))) >> queue
+                .offer(None)
+                .as(None)
             else
-              cb(Right(()))
+              F.delay(cb(Right(()))).as(None)
           }
         )
-        _ <- registerListener[std.Error](server, nodeStrings.error)(_.once_error(_, _)) { e =>
-          dispatcher.unsafeRunAndForget(error.complete(js.JavaScriptException(e)))
-        }
-        _ <- error.get
-          .race(
-            F
-              .async_[Unit] { cb =>
-                server.listen(
-                  address.foldLeft(
-                    netMod.ListenOptions().setPort(port.fold(0.0)(_.value.toDouble))
-                  )((opts, host) => opts.setHost(host.toString)),
-                  () => cb(Right(()))
-                )
+        _ <- F
+          .async_[Unit] { cb =>
+            server.once_error(nodeStrings.error, e => cb(Left(js.JavaScriptException(e))))
+            server.listen(
+              address.foldLeft(
+                netMod.ListenOptions().setPort(port.fold(0.0)(_.value.toDouble))
+              )((opts, host) => opts.setHost(host.toString)),
+              () => {
+                server.asInstanceOf[eventsMod.EventEmitter].removeAllListeners("error")
+                cb(Right(()))
               }
-          )
-          .rethrow
+            )
+          }
           .toResource
         ipAddress <- F
           .delay(server.address())
@@ -124,10 +123,9 @@ private[net] trait SocketGroupCompanionPlatform { self: SocketGroup.type =>
           }
           .toResource
         sockets = Stream
-          .fromQueueUnterminated(queue)
+          .fromQueueNoneTerminated(queue)
           .evalTap(setSocketOptions(options))
           .flatMap(sock => Stream.resource(Socket.forAsync(sock)))
-          .concurrently(Stream.eval(error.get.flatMap(F.raiseError[Unit])))
       } yield (ipAddress, sockets)).adaptError { case IOException(ex) => ex }
 
   }