Split up tests and add some heartbeats to try to make them not timeout.

pkg/watcher/test/no_subscription_test.dart

+// Copyright (c) 2012, 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.
+
+import 'dart:async';
+import 'dart:io';
+
+import 'package:scheduled_test/scheduled_test.dart';
+import 'package:watcher/watcher.dart';
+
+import 'utils.dart';
+
+main() {
+  initConfig();
+
+  setUp(createSandbox);
+
+  test('does not notify for changes when there were no subscribers', () {
+    // Note that this test doesn't rely as heavily on the test functions in
+    // utils.dart because it needs to be very explicit about when the event
+    // stream is and is not subscribed.
+    var watcher = createWatcher();
+
+    // Subscribe to the events.
+    var completer = new Completer();
+    var subscription = watcher.events.listen((event) {
+      expect(event.type, equals(ChangeType.ADD));
+      expect(event.path, endsWith("file.txt"));
+      completer.complete();
+    });
+
+    writeFile("file.txt");
+
+    // Then wait until we get an event for it.
+    schedule(() => completer.future);
+
+    // Unsubscribe.
+    schedule(() {
+      subscription.cancel();
+    });
+
+    // Now write a file while we aren't listening.
+    writeFile("unwatched.txt");
+
+    // Then start listening again.
+    schedule(() {
+      completer = new Completer();
+      subscription = watcher.events.listen((event) {
+        // We should get an event for the third file, not the one added while
+        // we weren't subscribed.
+        expect(event.type, equals(ChangeType.ADD));
+        expect(event.path, endsWith("added.txt"));
+        completer.complete();
+      });
+    });
+
+    // The watcher will have been cancelled and then resumed in the middle of
+    // its pause between polling loops. That means the second scan to skip
+    // what changed while we were unsubscribed won't happen until after that
+    // delay is done. Wait long enough for that to happen.
+    schedule(() => new Future.delayed(new Duration(seconds: 1)));
+
+    // And add a third file.
+    writeFile("added.txt");
+
+    // Wait until we get an event for the third file.
+    schedule(() => completer.future);
+
+    schedule(() {
+      subscription.cancel();
+    });
+  });
+}