fs,macos: fix fs_event_watch_dir_recursive flakiness

This test sometimes times out because not all the expected events are
received: the create and delete events may coalesce. To avoid it, make sure
not to start deleting the files until all the create events are received.
Also, take into account in the test that a create event of the `subdir`
directory can be detected even though we start watching for the events after its
creation.

test/test-fs-event.c

@@ -285,6 +285,12 @@ static void fs_event_cb_dir_multi_file_in_subdir(uv_fs_event_t* handle,
   if (filename && strcmp(filename, file_prefix_in_subdir) == 0)
     return;
 #endif
+  /* It may happen that the "subdir" creation event is captured even though
+   * we started watching after its actual creation.
+   */
+  if (strcmp(filename, "subdir") == 0)
+    return;
+
   fs_multievent_cb_called++;
   ASSERT(handle == &fs_event);
   ASSERT(status == 0);
@@ -293,18 +299,21 @@ static void fs_event_cb_dir_multi_file_in_subdir(uv_fs_event_t* handle,
   ASSERT(strncmp(filename,
                  file_prefix_in_subdir,
                  sizeof(file_prefix_in_subdir) - 1) == 0);
+
   #else
   ASSERT(filename == NULL ||
          strncmp(filename,
                  file_prefix_in_subdir,
                  sizeof(file_prefix_in_subdir) - 1) == 0);
   #endif
 
-  if (fs_event_created + fs_event_removed == fs_event_file_count) {
+  if (fs_event_created == fs_event_file_count &&
+      fs_multievent_cb_called == fs_event_created) {
     /* Once we've processed all create events, delete all files */
     ASSERT(0 == uv_timer_start(&timer, fs_event_unlink_files_in_subdir, 1, 0));
   } else if (fs_multievent_cb_called == 2 * fs_event_file_count) {
     /* Once we've processed all create and delete events, stop watching */
+    ASSERT(fs_event_removed == fs_event_file_count);
     uv_close((uv_handle_t*) &timer, close_cb);
     uv_close((uv_handle_t*) handle, close_cb);
   }