Add first image to frontmatter, replace youtube links with media embed components

gistfile1.txt

const fs = require('fs')
const path = require('path')

const FOLDER = './_posts'

fs.readdir(FOLDER, (err, files) => {
  if (err) return console.error(err)
  files.forEach(file => {
    const filepath = `${FOLDER}/${file}`
    if(path.extname(file) != '.md') return console.log(`${file} not markdown, passing`)
    fs.readFile(filepath, 'utf8', (err, content) => {
      const len = content.length
      if(err) return console.error(err)
      // check for thumbnails
      if(content.match(/thumbnail:/)) {
        // console.log(`${filepath} already has a thumbnail`)
      } else {
        const matches = content.match(/(?:!\[(.*?)\]\((.*?)\))/g)
        const image = matches ? matches[0].replace(/\!\[.*\]\(/, '').replace(/\)$/, '') : null
        if(image != null) {
          const title = content.match(/title:.*\n/)
          content = `${content.slice(0, title.index)}thumbnail: ${image}\n${content.slice(title.index)}`
        }
      }

      if(content.match(/youtube/)) {
        let result = content.match(/(<(https?\:\/\/)?(www\.)?(youtube\.com|youtu\.?be)\/.+)/i)

        if(result) {
          const url = result[0].replace(/<(.*)>.*/, '$1')
          content = `${content.slice(0, result.index)}<media-embed src='${url}'></media-embed>${content.slice(result.index + result[0].length)}`
        }
      }

      fs.writeFile(`${filepath}`, content, 'utf8', err => {
        if(err) console.error(err)
      })
    })
  })
})