index.cjs

'use strict';
// classic singleton yargs API, to use yargs
// without running as a singleton do:
// require('yargs/yargs')(process.argv.slice(2))
const {Yargs, processArgv} = require('./build/index.cjs');

Argv(processArgv.hideBin(process.argv));

module.exports = Argv;

function Argv(processArgs, cwd) {
  const argv = Yargs(processArgs, cwd, require);
  singletonify(argv);
  // TODO(bcoe): warn if argv.parse() or argv.argv is used directly.
  return argv;
}

function defineGetter(obj, key, getter) {
  Object.defineProperty(obj, key, {
    configurable: true,
    enumerable: true,
    get: getter,
  });
}
function lookupGetter(obj, key) {
  const desc = Object.getOwnPropertyDescriptor(obj, key);
  if (typeof desc !== 'undefined') {
    return desc.get;
  }
}

/*  Hack an instance of Argv with process.argv into Argv
    so people can do
    require('yargs')(['--beeble=1','-z','zizzle']).argv
    to parse a list of args and
    require('yargs').argv
    to get a parsed version of process.argv.
*/
function singletonify(inst) {
  [
    ...Object.keys(inst),
    ...Object.getOwnPropertyNames(inst.constructor.prototype),
  ].forEach(key => {
    if (key === 'argv') {
      defineGetter(Argv, key, lookupGetter(inst, key));
    } else if (typeof inst[key] === 'function') {
      Argv[key] = inst[key].bind(inst);
    } else {
      defineGetter(Argv, '$0', () => inst.$0);
      defineGetter(Argv, 'parsed', () => inst.parsed);
    }
  });
}