Complete with error if Worker fails.

dart/tests/isolate/spawn_uri_missing_from_isolate_test.dart

+// Copyright (c) 2014, 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 that Isolate.spawnUri completes with an error when the given URI
+/// doesn't resolve to an existing resource.
+///
+/// This test is similar to spawn_uri_missing_test.dart, but tests what happens
+/// when Isolate.spawnUri is called from an a spawned isolate.  In dart2js,
+/// these two situations are different.
+library test.isolate.spawn_uri_missing_from_isolate_test;
+
+import 'dart:isolate';
+
+import 'dart:async';
+
+import 'package:async_helper/async_helper.dart';
+
+import 'spawn_uri_missing_test.dart';
+
+const String SUCCESS = 'Test worked.';
+
+void isolate(SendPort port) {
+  doTest().then(
+      (_) => port.send(SUCCESS),
+      onError: (error, stack) => port.send('Test failed: $error\n$stack'));
+}
+
+main() {
+  ReceivePort port = new ReceivePort();
+  Isolate.spawn(isolate, port.sendPort);
+  Completer completer = new Completer();
+  port.listen((message) {
+    if (message == SUCCESS) {
+      completer.complete(null);
+    } else {
+      completer.completeError(message);
+    }
+  });
+
+  asyncTest(() => completer.future);
+}