updateExistingProperties.js

/**
 * Update values only for existing keys
 * @param {Object} outdated Object with old values
 * @param {Object} updated Object with updated values, it may have unnecessary keys.
 */
const updateExistingProperties = (outdated, updated) => {
  var result = {...outdated}
  for (let k of Object.keys(updated)) {
    // Ignore unnecessary keys
    if (!(k in result)) {
      continue
    }
    result[k] = updated[k]
  }
  return result
}