<img width="250" src="https://raw.githubusercontent.com/yargs/yargs/master/yargs-logo.png">

<b >Yargs be a node.js library fer hearties tryin' ter parse optstrings</b>

mocha [spec..]

Run tests with Mocha

Commands
  mocha inspect [spec..]  Run tests with Mocha                         [default]
  mocha init <path>       create a client-side Mocha setup at <path>

Rules & Behavior
  --allow-uncaught           Allow uncaught errors to propagate        [boolean]
  --async-only, -A           Require all tests to use a callback (async) or
                             return a Promise                          [boolean]

bash
npm i yargs

bash
npm i yargs@next

javascript
#!/usr/bin/env node
const yargs = require('yargs/yargs')
const { hideBin } = require('yargs/helpers')
const argv = yargs(hideBin(process.argv)).argv

if (argv.ships > 3 && argv.distance < 53.5) {
  console.log('Plunder more riffiwobbles!')
} else {
  console.log('Retreat from the xupptumblers!')
}

bash
$ ./plunder.js --ships=4 --distance=22
Plunder more riffiwobbles!

$ ./plunder.js --ships 12 --distance 98.7
Retreat from the xupptumblers!

javascript
#!/usr/bin/env node
const yargs = require('yargs/yargs')
const { hideBin } = require('yargs/helpers')

yargs(hideBin(process.argv))
  .command('serve [port]', 'start the server', (yargs) => {
    yargs
      .positional('port', {
        describe: 'port to bind on',
        default: 5000
      })
  }, (argv) => {
    if (argv.verbose) console.info(`start server on :${argv.port}`)
    serve(argv.port)
  })
  .option('verbose', {
    alias: 'v',
    type: 'boolean',
    description: 'Run with verbose logging'
  })
  .argv

npm i @types/yargs --save-dev

typescript
import yargs from 'https://deno.land/x/yargs/deno.ts'
import { Arguments } from 'https://deno.land/x/yargs/deno-types.ts'

yargs(Deno.args)
  .command('download <files...>', 'download a list of files', (yargs: any) => {
    return yargs.positional('files', {
      describe: 'a list of files to do something with'
    })
  }, (argv: Arguments) => {
    console.info(argv)
  })
  .strictCommands()
  .demandCommand(1)
  .argv

js
import yargs from 'yargs'
import { hideBin } from 'yargs/helpers'

yargs(hideBin(process.argv))
  .command('curl <url>', 'fetch the contents of the URL', () => {}, (argv) => {
    console.info(argv)
  })
  .demandCommand(1)
  .argv