Utilities used by lesky

Usage no npm install needed!

<script type="module">
  import lesUtils from 'https://cdn.skypack.dev/les-utils';


npm npm NPM

Les Utils (Less but still powerful)

This project was originally created to help support lesky. Originally, these utils were confined to that project, but since these utils can be nifty and reusable, I thought it would be wise to separate them out into their own project. That's exactly what this is. les-utils is less but versatile. With any luck, les-utils will become even less as the ES language features improve.


  1. First install globally

npm i -g les-utils

  1. Then to use in a project folder link to it:

npm link les-utils


import { LangUtils, PromiseUtils, Rexter, StringUtils } from 'les-utils'
// Currently exposed utils
// Read below for further explanation

Current utilities:

  1. Rexter: Like a good dog, fetches and requests things...sometimes in batch. Promise-based.

a) Example: (single request)

const rexter = Rexter({ host: api.host.com })
const resp = await rexter.request({ path: '/some/data/123' })

b) Example: (batch request)

const rexter = Rexter({ host: api.host.com, auth: 'user:pass' }) // in case auth is needed
const userIds = ['123', '453', '897']
const resp = await rexter.requestMany({
  items: userIds
  pathTemplate: '/some/data/[ITEM]', // [ITEM] will be replaced by each userId
  outputFmt: 'json', // Can be 'json', 'string', or 'xml' (default is buffered byte stream)
  notify({ data }) { // Set up an optional per-item notification handler 
    const { item, resp } = data
    // If interested, handle each items response as it comes in
    // otherwise, it's sufficient to simply wait for the promise to resolve
  1. Language:
  • Gets a list of supported languages from the specified service (currently supported services are Yandex and IBM)
  • Translates text using those APIs. (IBM and Yandex require free API keys, but the free limits are pretty good!)
  1. String:
  • ParseXML (promise-based)
  • Camelcase
  • Startcase
  1. Promises:
  • PromiseUtils.delay (a promise-based delay method so you can stop calling setTimeout. Easy!)
  • PromiseUtils.each (similar to async.each but promise-based and more versatile)
  • PromiseUtils.series (similar to async.series but promise-based and more versatile)

a) Example:

const items = ['item1', 'item2']
const resp = await PromiseUtils.each({
  async handleItem() {
    await PromiseUtils.delay(100)
    return 'ok'
  notify({ evt, data }) {
    const { item, resp } = data
    // do something with item's resp if you want
// resp = { item1: 'ok', item2: 'ok' }

Why not just use Promise.all? In many cases, yes, I'm happy to use Promise.all. However, if there are MANY promises to be fulfilled, I like to have the option to be notified when each promise has been fulfilled. I found this to a be a relatively simple way to do what I want.

  1. Security:
  • generateSelfSignedCert (does what it says)
  1. NetUtils:
  • findFreePort (finds a free port for a specified range)
  • isPortTaken (does what it says)