Convert a markdown note written in Notable (https://github.com/notable/notable) to a markdown document readable by another Markdown editor like Typora (https://typora.io/) via a CLI node script

notableNoteToTypora.js

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

/**
 * Info option, when true enable performance tracking and other infos
 */
let enableInfo = false

/**
 * String that replaces `@attachment` in `img` tags
 */
let replaceWith = 'attachments'

/**
 * CLI Help output
 */
const helpOutput = () => {
  console.log('Description:\n' +
   '\tScraps Markdown note created with Notable for used resources to\n' +
   '\tedit it and export it to a new file that can be edited in Typora.')
  console.log('Example:\n\t$ node ' +
    colors.yellow('.\\notableNoteToTypora.js ') +
    colors.green('filePath.md ') +
    colors.red('-enableOptionalOption') +
    '\n\tFile was written: "filePath_typora.md"')
  console.log('Options:\n' + '\t-info\t\t\t\t' +
    colors.grey('Get information about performance\n\t\t\t\t\tand other things') +
    '\n\t-customReplace ' + colors.magenta('"attachmentsDir"') + '\t' +
    colors.grey('Replace "@attachment" in img tags\n\t\t\t\t\twith a custom string'))
}

/**
 * CLI Version output
 */
const versionOutput = () => {
  console.log('0.0.2')
}

// Check if a file was given
if (process.argv.length < 3) {
  console.error('No file path specified!\n')
  helpOutput()
  process.exit(1)
}

// Check if options are correct
if (process.argv.length >= 3) {
  let infoAlreadyEnabled = false
  let replaceAlreadyEnabled = false
  let ignoreNext = false

  for (let i = 3; i < process.argv.length; i++) {
    if (process.argv[i] === '-info') {
      if (infoAlreadyEnabled) {
        console.error(`'-info' option cannot bet enabled twice!\n`)
        helpOutput()
        process.exit(1)
      } else {
        infoAlreadyEnabled = true
        enableInfo = true
      }
    } else if (process.argv[i] === '-customReplace') {
      if (replaceAlreadyEnabled) {
        console.error(`'-customReplace' option cannot bet enabled twice!\n`)
        helpOutput()
        process.exit(1)
      } else {
        replaceAlreadyEnabled = true
        if (i + 1 > process.argv.length) {
          console.error(`'-customReplace' option needs a following argument!\n`)
          helpOutput()
          process.exit(1)
        }
        ignoreNext = true
        replaceWith = process.argv[i + 1]
      }
    } else {
      if (!ignoreNext) {
        console.error(`Unknown option: "${colors.red(process.argv[i])}"\n`)
        helpOutput()
        process.exit(1)
      } else {
        ignoreNext = false
      }
    }
  }
}

// Check if instead of a file help/version is wanted
if (process.argv[2] === '--help' ||
    process.argv[2] === '-help' ||
    process.argv[2] === 'help') {
  helpOutput()
  process.exit(0)
} else if (process.argv[2] === '--version' ||
    process.argv[2] === '-version' ||
    process.argv[2] === 'version') {
  versionOutput()
  process.exit(0)
}

/**
 * File path file
 */
const filePath = process.argv[2]

// Check if file exists
if (!fs.existsSync(filePath)) {
  console.error(`File was not found: "${colors.red(filePath)}"\n`)
  helpOutput()
  process.exit(1)
}

/**
 * Regex to find image resources
 * ```js
 * const aString = '<img src="@attachment/test.svg" >' +
 *   '<img src="@attachment/test.png">'
 * let match = regexImageResource.exec(aString)
 * while (match !== null) {
 *   // <img src="@attachment/test.svg" >, <img src="@attachment/test.png" >
 *   console.log(match[1])
 *   match = regexImageResource.exec(aString)
 * }
 * ```
 */
const regexImageResource = /<img .*src="@attachment\/.*?".*>/g

/**
 * Extract all matches from the file via a fs.stream (much faster
 * when executing on large files)
 * @param {string} filePath File that should be read
 * @returns {Promise<Buffer>} Array with buffer for file to edit
 */
async function createdBufferFromFileViaStream (filePath) {
  return new Promise((resolve, reject) => {
    const label = `createdBufferFromFileViaStream (${filePath})`
    if (enableInfo) { console.time(label) }
    let buffer = null
    const stream = fs.createReadStream(filePath, { encoding: 'utf8' })
    stream.on('data', data => {
      buffer = Buffer.from(data
        .replace(regexImageResource,
          (everything) => everything.replace(/@attachment/g, replaceWith))
        // Remove notable information (if found at the top)
        .replace(/^---[\s\S]*?---[\s]*/m, ''))
      stream.destroy()
    }).on('error', err => {
      if (enableInfo) { console.timeEnd(label) }
      reject(err)
    }).on('close', () => {
      if (enableInfo) { console.timeEnd(label) }
      resolve(buffer)
    })
  })
}

/**
 * Write file
 * @param {string} filePath
 * @param {Buffer} buffer
 */
async function writeToFile (filePath, buffer) {
  return new Promise((resolve, reject) => {
    const label = `writeBufferToNewFile (${filePath})`
    if (enableInfo) { console.time(label) }
    fs.open(filePath, 'w', function (err, fd) {
      if (err) {
        if (enableInfo) { console.timeEnd(label) }
        return reject(err)
      }
      fs.write(fd, buffer, 0, buffer.length, () => { }, (err) => {
        if (err) {
          if (enableInfo) { console.timeEnd(label) }
          return reject(err)
        }
        fs.close(fd, () => {
          if (enableInfo) { console.timeEnd(label) }
          resolve()
        })
      })
    })
  })
}

// MAIN
// Create new file for use in Typora
createdBufferFromFileViaStream(filePath)
  .then(buffer => {
    const newFilePath = path.join(path.dirname(filePath),
      path.basename(filePath, path.extname(filePath)) +
      '_typora' + path.extname(filePath))
    writeToFile(newFilePath, buffer).then(() => {
      console.log(`File was written: "${newFilePath}"`)
    }).catch(console.error)
  })
  .catch(console.error)

notableNoteToTypora.txt

Description:
        Scraps Markdown note created with Notable for used resources to
        edit it and export it to a new file that can be edited in Typora.
Example:
        $ node .\notableNoteToTypora.js filePath.md -enableOptionalOption
        File was written: "filePath_typora.md"
Options:
        -info                           Get information about performance
                                        and other things
        -customReplace "attachmentsDir" Replace "@attachment" in img tags
                                        with a custom string

notableNoteToTypora_example_filePath.md

title	tags	created	modified	attachments
A title	Notebooks/Test	2019-02-17T19:54:53.942Z	2019-02-19T16:27:42.872Z	test.svg

A title

Another section