git

#!/usr/bin/env node

const {parserSync} = require('shargs')
const {command, flag, string, subcommand, variadicPos} = require('shargs/opts')
const {flagAsNumber, flagsAsBools, splitShortOpts} = require('shargs/parser')
const {desc, optsListsWith, space, synopses, usage} = require('shargs/usage')

const init = subcommand([
  flag('quiet', ['-q', '--quiet'], {desc: 'Only print error and warning messages.'})
])

const commit = subcommand([
  flag('all', ['-a', '--all'], {desc: 'Automatically stage files that have been modified and deleted.'}),
  string('message', ['-m', '--message'], {descArg: 'msg', desc: 'Use <msg> as the commit message.'}),
  variadicPos('file', {desc: 'A list of files to commit.'})
])

const opts = [
  flag('help', ['--help'], {desc: 'Print this help message.'}),
  init('init', ['init'], {desc: 'Create an empty Git repository or reinitialize an existing one.'}),
  commit('commit', ['commit'], {desc: 'Record changes to the repository.'})
]

const git    = command('git', opts, {desc: 'A simple command-line interface for git.'})

const stages = {
  argv: [splitShortOpts],
  args: [flagAsNumber('quiet'), flagsAsBools]
}

const parser = parserSync(stages)
const parse  = parser(git)

const argv   = process.argv.slice(2)
const res    = parse(argv)

if (res.args.help) {
  const style = {
    line: [{width: 50}],
    cols: [{width: 20}, {width: 30}]
  }
  const help = usage([
    synopses,
    space,
    optsListsWith({pad: 2}),
    space,
    desc
  ])(git)(style)
  console.log(help)
} else {
  console.log(JSON.stringify(res, null, 2))
}