sth.js

/**
 * @file Some description of the file
 * @author Me
 */

import something from 'somewhere';

const SOMETHING = {
  some: 'thing'
}

/**
 * Description about the function below.
 * This is the comment that styleguidist picks.
 * @return {Boolean}
 */
function isSomething(someKey) {
  return someKey in SOMETHING;
}