/* eslint-disable no-param-reassign */
function isObject(obj) {
  return (
    obj !== null &&
    typeof obj === 'object' &&
    'constructor' in obj &&
    obj.constructor === Object
  );
}

function extend(target: any = {}, src: any = {}) {
  Object.keys(src).forEach((key) => {
    if (typeof target[key] === 'undefined') target[key] = src[key];
    else if (
      isObject(src[key]) &&
      isObject(target[key]) &&
      Object.keys(src[key]).length > 0
    ) {
      extend(target[key], src[key]);
    }
  });
}

export default extend;