// Licensed to Cloudera, Inc. under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  Cloudera, Inc. licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License.  You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

export type Node = { [key: string]: Node };

const dfs = (node: Node, callback: (node: Node, key: string) => void): void => {
  if (!node || typeof node !== 'object') {
    return;
  }
  Object.keys(node).forEach(key => {
    callback(node, key);
    dfs(node[key], callback);
  });
};

const deleteAllEmptyStringKeys = (node: Node): void => {
  dfs(node, (node: Node, key: string) => {
    if (node[key] || typeof node[key] !== 'string') {
      return;
    }
    delete node[key];
  });
};

export default deleteAllEmptyStringKeys;