Added toMultiSubscriber on Stream.

tests/lib/async/stream_single_to_multi_subscriber_test.dart

+// Copyright (c) 2011, 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.
+
+// Test the basic StreamController and StreamController.singleSubscription.
+library stream_single_test;
+
+import 'dart:async';
+import 'dart:isolate';
+import '../../../pkg/unittest/lib/unittest.dart';
+import 'event_helper.dart';
+
+main() {
+  test("tomulti 1", () {
+    StreamController c = new StreamController<int>.singleSubscription();
+    Stream<int> multi = c.stream.asMultiSubscriberStream();
+    // Listen twice.
+    multi.listen(expectAsync1((v) => Expect.equals(42, v)));
+    multi.listen(expectAsync1((v) => Expect.equals(42, v)));
+    c.add(42);
+  });
+
+  test("tomulti 2", () {
+    StreamController c = new StreamController<int>.singleSubscription();
+    Stream<int> multi = c.stream.asMultiSubscriberStream();
+    Events expected = new Events.fromIterable([1, 2, 3, 4, 5]);
+    Events actual1 = new Events.capture(multi);
+    Events actual2 = new Events.capture(multi);
+    actual1.onDone(expectAsync0(() {
+      Expect.listEquals(expected.events, actual1.events);
+    }));
+    actual2.onDone(expectAsync0(() {
+      Expect.listEquals(expected.events, actual2.events);
+    }));
+    expected.replay(c);
+  });
+
+  test("tomulti no-op", () {
+    StreamController c = new StreamController<int>();
+    Stream<int> multi = c.stream.asMultiSubscriberStream();
+    Events expected = new Events.fromIterable([1, 2, 3, 4, 5]);
+    Events actual1 = new Events.capture(multi);
+    Events actual2 = new Events.capture(multi);
+    actual1.onDone(expectAsync0(() {
+      Expect.listEquals(expected.events, actual1.events);
+    }));
+    actual2.onDone(expectAsync0(() {
+      Expect.listEquals(expected.events, actual2.events);
+    }));
+    expected.replay(c);
+  });
+}