PatrickYeungts/difference.js

/**
 * This code is licensed under the terms of the MIT license
 * from https://gist.github.com/Yimiprod/7ee176597fef230d1451
 *
 * Deep diff between two object, using lodash
 *
 * updated with:
 * before diff the object compared will be normalized to base
 *
 * @param  {Object} object Object compared
 * @param  {Object} base   Object to compare with
 * @return {Object}        Return a new object who represent the diff
 */
function difference(object, base) {
  if (!base || !object) return object ?? base;
  function normalize(object, base) {
    return !_.isArray(object) ? [...new Set([...Object.keys(object), ...Object.keys(base)])].reduce(
      (acc, key) => ({ ...acc, [key]: object[key] }),
      {}
    ) : object;
  }

  function changes(object, base) {
    return _.transform(object, function (result, value, key) {
      if (!_.isEqual(value, base[key])) {
        result[key] =
          _.isObject(value) && _.isObject(base[key])
            ? changes(normalize(value, base[key]), base[key])
            : value;
      }
    });
  }
  return changes(normalize(object, base), base);
}