Update dart:io tests to use asyncStart/asyncEnd

tests/standalone/io/socket_exception_test.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 //
 // Tests socket exceptions.
 
+import "dart:async";
+import "dart:io";
+
+import "package:async_helper/async_helper.dart";
 import "package:expect/expect.dart";
-import "dart:async";
-import "dart:isolate";
-import "dart:io";
 
 class SocketExceptionTest {
 
   static void serverSocketExceptionTest() {
     bool exceptionCaught = false;
     bool wrongExceptionCaught = false;
 
     ServerSocket.bind("127.0.0.1", 0).then((server) {
       Expect.isNotNull(server);
       server.close();
       try {
         server.close();
       } on SocketException catch(ex) {
         exceptionCaught = true;
       } catch (ex) {
         wrongExceptionCaught = true;
       }
       Expect.equals(false, exceptionCaught);
       Expect.equals(true, !wrongExceptionCaught);
 
       // Test invalid host.
       ServerSocket.bind("__INVALID_HOST__", 0)
         .then((server) { })
         .catchError((e) => e is SocketException);
     });
   }
 
   static void serverSocketCloseListenTest() {
-    var port = new ReceivePort();
+    asyncStart();
     ServerSocket.bind("127.0.0.1", 0).then((server) {
       Socket.connect("127.0.0.1", server.port).then((socket) {
         server.close();
         server.listen(
           (incoming) => Expect.fail("Unexpected socket"),
-          onDone: port.close);
+          onDone: asyncEnd);
       });
     });
   }
 
   static void serverSocketListenCloseTest() {
-    var port = new ReceivePort();
+    asyncStart();
     ServerSocket.bind("127.0.0.1", 0).then((server) {
       Socket.connect("127.0.0.1", server.port).then((socket) {
         server.listen(
           (incoming) => server.close(),
-          onDone: port.close);
+          onDone: asyncEnd);
       });
     });
   }
 
   static void clientSocketExceptionTest() {
     bool exceptionCaught = false;
     bool wrongExceptionCaught = false;
 
     ServerSocket.bind("127.0.0.1", 0).then((server) {
       Expect.isNotNull(server);
@@ skipping 104 matching lines @@
               // We get either a close or an error followed by a close
               // on the socket.  Whether we get both depends on
               // whether the system notices the error for the read
               // event or only for the write event.
               Expect.isTrue(errors <= 1);
               server.close();
             });
         client.add(new List.filled(SIZE, 0));
         // Destroy other socket now.
         completer.complete(null);
-        var port = new ReceivePort();
+        asyncStart();
         client.done.then(
             (_) {
               Expect.fail("Expected error");
             },
             onError: (error) {
               Expect.isTrue(error is SocketException);
-              port.close();
+              asyncEnd();
             });
       });
     });
   }
 
   static void clientSocketAddCloseResultErrorTest() {
     ServerSocket.bind("127.0.0.1", 0).then((server) {
       var completer = new Completer();
       server.listen((socket) {
         completer.future.then((_) => socket.destroy());
       });
       Socket.connect("127.0.0.1", server.port).then((client) {
         const int SIZE = 1024 * 1024;
         int errors = 0;
         client.add(new List.filled(SIZE, 0));
         client.close();
         client.done.catchError((error) {
           server.close();
         });
         // Destroy other socket now.
         completer.complete(null);
       });
     });
   }
 
   static void unknownHostTest() {
-    // Port to verify that the test completes.
-    var port = new ReceivePort();
-    port.receive((message, replyTo) => null);
-
+    asyncStart();
     Socket.connect("hede.hule.hest", 1234)
         .then((socket) => Expect.fail("Connection completed"))
-        .catchError((e) => port.close(), test: (e) => e is SocketException);
+        .catchError((e) => asyncEnd(), test: (e) => e is SocketException);
 
   }
 
   static void testMain() {
     serverSocketExceptionTest();
     serverSocketCloseListenTest();
     serverSocketListenCloseTest();
     clientSocketExceptionTest();
     clientSocketDestroyNoErrorTest();
     clientSocketAddDestroyNoErrorTest();
     clientSocketAddCloseNoErrorTest();
     clientSocketAddCloseErrorTest();
     clientSocketAddCloseResultErrorTest();
     unknownHostTest();
   }
 }
 
 main() {
+  asyncStart();
   SocketExceptionTest.testMain();
+  asyncEnd();
 }