const promisify = (func, ...args) => {
  return new Promise((resolve, reject) => {
    func(...args, (err, value) => {
      if (err) {
        reject(err)
      } else {
        resolve(value)
      }
    })
  })
}

promisify(getPosts)
  .then((articles) => Promise.all(articles.map((article) => promisify(getComments, article.id))))
  .then(console.log)
  .catch(console.error)

console.log('fetchedVideo:', fetchedVideo.tips[2].description)