Extract used image resources from a note written in Notable (https://github.com/notable/notable) via a CLI node script

notableNoteGetImgs.js

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

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

/**
 * JSON option, return image paths in JSON format
 */
let enableJson = false

/**
 * CLI Help output
 */
const helpOutput = () => {
  console.log('Description:\n' +
   '\tScraps Markdown note created with Notable for used resources to\n' +
   '\texport it even when some attachments were forgotten')
  console.log('Example:\n\t$ node ' +
    colors.yellow('.\\notableNoteGetImgs.js ') +
    colors.green('filePath.md ') +
    colors.magenta('-enableOptionalOption') +
    '\n\tattachments:[test.svg,test.png]')
  console.log('Options:\n' + '\t-info\t' +
    colors.grey('Get information about performance and other things') +
    '\n\t-json\t' +
    colors.grey('Get all image paths in JSON format'))
}

/**
 * CLI Version output
 */
const versionOutput = () => {
  console.log('0.0.6')
}

// 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 >= 4) {
  for (let i = 3; i < process.argv.length; i++) {
    if (process.argv[i] === '-json') {
      enableJson = true
    } else if (process.argv[i] === '-info') {
      enableInfo = true
    } else {
      console.error(`Unknown option: "${colors.red(process.argv[i])}"\n`)
      helpOutput()
      process.exit(1)
    }
  }
}

// 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) {
 *   // test.svg, test.png
 *   console.log(match[1])
 *   match = regexImageResource.exec(aString)
 * }
 * ```
 */
const regexImageResource = /<img .*?src="@attachment\/(.*?)" .*?>/g

/**
 * Get all connected resources
 * @param {string} fileContent The file content string
 */
function extractConnectedResources (fileContent) {
  const matches = []
  // Extract all image resources
  let match = regexImageResource.exec(fileContent)
  while (match !== null) {
    matches.push(match[1])
    match = regexImageResource.exec(fileContent)
  }
  // Return all matches
  return matches
}

/**
 * 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<string[]>} Array with all found attachments
 */
async function extractMatchesFromFileViaStream (filePath) {
  return new Promise((resolve, reject) => {
    const label = `extractMatchesFromFileViaStream (${filePath})`
    if (enableInfo) { console.time(label) }
    const matches = []
    const stream = fs.createReadStream(filePath, { encoding: 'utf8' })
    stream.on('data', data => {
      matches.push(...extractConnectedResources(data))
      stream.destroy()
    }).on('error', err => {
      if (enableInfo) { console.timeEnd(label) }
      reject(err)
    }).on('close', () => {
      const uniqueMatches = [...new Set(matches)]
      if (enableInfo) { console.timeEnd(label) }
      resolve(uniqueMatches)
    })
  })
}

// MAIN
// Get matches
extractMatchesFromFileViaStream(filePath)
  .then(matches => {
    // Format found matches for a string that can be copy-pasted
    if (enableJson) {
      console.log(JSON.stringify({ imagePaths: matches }, null, 0))
    } else {
      console.log('attachments:[' + matches.join(',') + ']')
    }
  })
  .catch(console.error)

notableNoteGetImgs.txt

Description:
        Scraps Markdown note created with Notable for used resources to
        export it even when some attachments were forgotten
Example:
        $ node .\notableNoteGetImgs.js filePath.md -enableOptionalOption
        attachments:[test.svg,test.png]
Options:
        -info   Get information about performance and other things
        -json   Get all image paths in JSON format

notableNoteGetImgs_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