def test_reap_tmp_images(self, _allow_grace_period, _os_datastore_path,
                             _uuid):
        """ Test that stray images are found and deleted by the reaper """

        def _fake_ds_folder(datastore, folder):
            return "%s__%s" % (datastore, folder)

        ds = MagicMock()
        ds.id = "dsid"
        ds.type = DatastoreType.EXT3

        # In a random transient directory, set up a directory to act as the
        # tmp images folder and to contain a stray image folder with a file.
        tmpdir = file_util.mkdtemp(delete=True)
        tmp_images_folder = _fake_ds_folder(ds.id, TMP_IMAGE_FOLDER_NAME)
        tmp_images_dir = os.path.join(tmpdir, tmp_images_folder)
        tmp_image_dir = os.path.join(tmp_images_dir, "stray_image")
        os.mkdir(tmp_images_dir)
        os.mkdir(tmp_image_dir)
        (fd, path) = tempfile.mkstemp(prefix='strayimage_', dir=tmp_image_dir)

        self.assertTrue(os.path.exists(path))

        def _fake_os_datastore_path(datastore, folder):
            return os.path.join(tmpdir, _fake_ds_folder(datastore, folder))

        _os_datastore_path.side_effect = _fake_os_datastore_path

        ds_manager = MagicMock()
        ds_manager.get_datastores.return_value = [ds]
        image_manager = EsxImageManager(self.vim_client, ds_manager)
        if not _allow_grace_period:
            image_manager.REAP_TMP_IMAGES_GRACE_PERIOD = 0.0
            time.sleep(0.1)
        image_manager.reap_tmp_images()

        if _allow_grace_period:
            # verify stray image is not deleted due to grace period
            self.assertTrue(os.path.exists(path))
        else:
            # verify stray image is deleted
            self.assertFalse(os.path.exists(path))