add default root directory

weed/filer2/leveldb/leveldb_store_test.go

@@ -59,3 +59,25 @@ func TestCreateAndFind(t *testing.T) {
 	}
 
 }
+
+func TestEmptyRoot(t *testing.T) {
+	filer := filer2.NewFiler(nil)
+	dir, _ := ioutil.TempDir("", "seaweedfs_filer_test2")
+	defer os.RemoveAll(dir)
+	store := &LevelDBStore{}
+	store.initialize(dir)
+	filer.SetStore(store)
+	filer.DisableDirectoryCache()
+
+	// checking one upper directory
+	entries, err := filer.ListDirectoryEntries(filer2.FullPath("/"), "", false, 100)
+	if err != nil {
+		t.Errorf("list entries: %v", err)
+		return
+	}
+	if len(entries) != 0 {
+		t.Errorf("list entries count: %v", len(entries))
+		return
+	}
+
+}