Add a VmListener and IsolateTest class for running tests in other isolates.

lib/src/isolate_test.dart

+// Copyright (c) 2015, 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.
+
+library unittest.isolate_test;
+
+import 'dart:isolate';
+
+import 'live_test.dart';
+import 'live_test_controller.dart';
+import 'remote_exception.dart';
+import 'state.dart';
+import 'suite.dart';
+import 'test.dart';
+
+/// A test in another isolate.
+class IsolateTest implements Test {
+  final String name;
+
+  /// The port on which to communicate with the remote test.
+  final SendPort _sendPort;
+
+  IsolateTest(this.name, this._sendPort);
+
+  /// Loads a single runnable instance of this test.
+  LiveTest load(Suite suite) {
+    var receivePort;
+    var controller;
+    controller = new LiveTestController(suite, this, () {
+      controller.setState(const State(Status.running, Result.success));
+
+      receivePort = new ReceivePort();
+      _sendPort.send({
+        'command': 'run',
+        'reply': receivePort.sendPort
+      });
+
+      receivePort.listen((message) {
+        if (message['type'] == 'error') {
+          var asyncError = RemoteException.deserialize(message['error']);
+          controller.addError(asyncError.error, asyncError.stackTrace);
+        } else if (message['type'] == 'state-change') {
+          controller.setState(
+              new State(
+                  new Status.parse(message['status']),
+                  new Result.parse(message['result'])));
+        } else {
+          assert(message['type'] == 'complete');
+          controller.completer.complete();
+        }
+      });
+    }, onClose: () {
+      if (receivePort != null) receivePort.close();
+    });
+    return controller.liveTest;
+  }
+}