Javascript is not returning objects as expected

Question

Javascript (or Node.js) is not returning objects as expected.

The following code logs an empty array.

const _sodium = require('libsodium-wrappers');

const sodium = (async () => {
  await _sodium.ready;
  return _sodium;
})();

console.log(Object.getOwnPropertyNames(sodium));

On the other hand, the following code works as expected.

const _sodium = require('libsodium-wrappers');

(async () => {
  await _sodium.ready;
  const sodium = _sodium;
  console.log(Object.getOwnPropertyNames(sodium));
})();

In the first code snippet, it seems like the sodium object is tied to its lexical environment, which would explain why an empty array is printed. I would be interested in what's going on here (including an explanation of what's going on under the hood). Thanks.

In your first snippet, `sodium` is a promise. Log the object itself, not its property names, it'll be obvious — Bergi, Sep 24 '22 at 19:26

score 0 · Accepted Answer · answered Sep 24 '22 at 19:26

It's not about lexical context.

You just not awaiting for ready in the first example.

First example simplified:

(async() => {
  console.log('start')
  await new Promise(r => setTimeout(r, 3000))
  console.log('finish')
})()

Second example simplified:

console.log('start');
(async() => {
  await new Promise(r => setTimeout(r, 3000))
})();
console.log('finish')

Javascript is not returning objects as expected

1 Answers1