Quick object merging.

merge.js

/**
 * @export merge
 *
 * @param {object} object The object to merge with
 * @param {object} source The object to merge
 * @return {object} merge result
 */
export const merge = (object = {}, source = {}) => {
  // deep assign
  for (const key of Object.keys(object)) {
    if (source[key]) {
      Object.assign(object[key], source[key]);
    }
  }
  // assign the rest
  for (const key of Object.keys(source)) {
    if (!object[key]) {
      object[key] = source[key];
    }
  }
  return object;
}