Wrap Directory.watch on Mac OS for the watcher package.

pkg/watcher/test/directory_watcher/shared.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 'package:scheduled_test/scheduled_test.dart';
 
 import '../utils.dart';
 
+import 'dart:async';
+
 sharedTests() {
   test('does not notify for files that already exist when started', () {
     // Make some pre-existing files.
     writeFile("a.txt");
     writeFile("b.txt");
 
     startWatcher();
 
     // Change one after the watcher is running.
     writeFile("b.txt", contents: "modified");
@@ skipping 192 matching lines @@
       startWatcher(dir: "dir");
       renameDir("dir/old", "dir/new");
 
       inAnyOrder(() {
         withPermutations((i, j, k) {
           expectRemoveEvent("dir/old/sub-$i/sub-$j/file-$k.txt");
           expectAddEvent("dir/new/sub-$i/sub-$j/file-$k.txt");
         });
       });
     });
+
+    test("emits events for many files added at once in a subdirectory with the "
+        "same name as a removed file", () {
+      writeFile("dir/sub");
+      withPermutations((i, j, k) =>
+          writeFile("old/sub-$i/sub-$j/file-$k.txt"));
+      startWatcher(dir: "dir");
+
+      deleteFile("dir/sub");
+      renameDir("old", "dir/sub");
+      inAnyOrder(() {
+        expectRemoveEvent("dir/sub");
+        withPermutations((i, j, k)  =>
+            expectAddEvent("dir/sub/sub-$i/sub-$j/file-$k.txt"));
+      });
+    });
   });
 }