build.js

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

// Gets array of all directories within a specified path
const getDirectories = path => fs
  .readdirSync(path)
  .filter(file => fs
    .statSync(`${path}/${file}`)
    .isDirectory()
  )

const listing = getDirectories(path.resolve(__dirname, './api/clean'))
let modjs = fs.createWriteStream('./module.js')

modjs.on('open', () => {
  modjs.write(`// THIS IS AN AUTO-GENERATED FILE, DO NOT MANUALLY MODIFY\n\n`)
  modjs.write(`module.exports = {`)
  listing.forEach((apiType, i) => {
    modjs.write(`${i === 0 ? '\n' : ',\n'}  '${apiType}': {`)
    fs.readdirSync(path.resolve(__dirname, `./api/clean/${apiType}`), 'utf8')
      .filter(f => f.indexOf('.js') === f.length - 3) // only files with .js extension
      .map(f => f.slice(0, f.length - 3))
      .forEach((f, k) => {
        modjs.write(`${k === 0 ? '\n' : ',\n'}    '${f}': require('./api/clean/${apiType}/${f}.js')`)
      })
    modjs.write('\n  }')
  })

  modjs.write(`,\n  'utils': {`)
  fs.readdirSync(path.resolve(__dirname, `./api/util/`), 'utf8')
    .filter(f => f.indexOf('.js') === f.length - 3) // only files with .js extension
    .map(f => f.slice(0, f.length - 3))
    .forEach((f, k) => {
      const mn = f
        .split('-')
        .map((a, i) => i > 0 // exclude first (for camelCase)
          ? a[0].toUpperCase() + a.substring(1) // up the 1st char & combine
          : a
        )
        .join('')
      modjs.write(`${k === 0 ? '\n' : ',\n'}    '${mn}': require('./api/util/${f}.js')`)
    })
  modjs.write('\n  }')
  modjs.write('\n}\n')
})

fs.readFile(`./package.json`, 'utf8', (err, data) => {
  if (err) return console.log(err)
  const newContents = data
    .split('\n')
    .map(line => {
      if (line.indexOf(`"version"`) === -1) return line
      const sp1 = line.split(`:`) // ['  "version"', ' "2.0.0",']
      const sp2 = sp1[1].split(`"`) // [' ', '2.0.0', ',']
      const vers = sp2[1].split(`.`).map(a => Number(a)) // [2, 0, 0]
      vers[vers.length - 1] += 1 // updates last version number
      sp2[1] = vers.join(`.`)
      sp1[1] = sp2.join(`"`)

      line = sp1.join(`:`)
      return line
    })
    .join('\n')

  fs.writeFile(`./package.json`, newContents, 'utf8', (err) => {
    if (err) return console.log(err)
  })
})