object-diff.js

// From: NicolasLetellier @ https://gist.github.com/Yimiprod/7ee176597fef230d1451#gistcomment-3058093

function objectDiff(object, base) {
  function changes(object, base) {
    const accumulator = {};
    Object.keys(base).forEach((key) => {
      if (object[key] === undefined) {
        accumulator[`-${key}`] = base[key];
      }
    });
    return _.transform(
      object,
      (accumulator, value, key) => {
        if (base[key] === undefined) {
          accumulator[`+${key}`] = value;
        } else if (!_.isEqual(value, base[key])) {
          accumulator[key] = (_.isObject(value) && _.isObject(base[key])) ? changes(value, base[key]) : value;
        }
      },
      accumulator
    );
  }
  return changes(object, base);
}

/**
 * create object that reflects the difference where each primitive value is an array of the before and after values
 * @param {object} before 
 * @param {object} after 
 * @returns {object}
 */
function objectDiffBeforeAfter(before, after) {
  function changes(before, after) {
    const accumulator = {};
    Object.keys(after).forEach((key) => {
      if (before[key] === undefined) {
        accumulator[key] = [undefined, after[key]];
      }
    });
    return _.transform(
      before,
      (accumulator, value, key) => {
        if (after[key] === undefined) {
          accumulator[key] = [value, undefined];
        } else if (!_.isEqual(value, after[key])) {
          accumulator[key] = (_.isObject(value) && _.isObject(after[key])) ? changes(value, after[key]) : [value, after[key]];
        }
      },
      accumulator
    );
  }
  return changes(before, after);
}