async.js

async function detect() { }
const r = detect();
const nativeThen = r.__proto__.then;
r.__proto__.then = function () {
  console.log('promise.then');
  return nativeThen.apply(this, arguments);
}

async function test1() {
  console.log('before await');
  const r = await test();
  console.log('after await');
}

test1();
console.log('end');

// the output will be
// before await
// end
// promise.then, question is why promise.then is after end?
// after await