Turn async await into tuple output

tuple-ification-of-promise.js

/**
 * Tuple-ification of a promise result
 * @method to
 * @param {promise} p
 * @returns {array}
 */
const to = p => p.then(res => [null, res]).catch(err => [err]);

/**
 * Test success promise
 * @returns {promise}
 */
const test1 = async () => "ok";

/**
 * Test fail promise
 * @returns {promise}
 */
const test2 = async () => { throw new Error("not ok =["); };

async function start() {
  // 💰
  const [ err, res ] = await to(test1());
  console.log("err", err) // null
  console.log("res", res) // "ok"
  
  const [ err2, res2 ] = await to(test2());
  // 💰
  console.log("err2", err2) // Error: not ok
  console.log("res2", res2) // undefined
}

console.log(start()); // Promise { <pending> }

// more reading
// https://blog.grossman.io/how-to-write-async-await-without-try-catch-blocks-in-javascript/

Object version https://gist.github.com/tcrowe/d025922d56d25dbd4ec89fb966387f4d