One can use await keyword outside of async functions with Top-level await and the happy news is you can use it today in node and REPL.

As of today, if we execute the bleow peice of code in node env:

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await Promise.resolve(42);

We would see a: SyntaxError: await is only valid in async function

So, we would normally mitigate this by wrapping it in an async function:

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(async function() {
  const answer = await Promise.resolve(42);
  // answer would be 42
}());

But with top level await it get's easier we could just do const answer = await Promise.resolve(42); note that this will only work at the top level of modules only.

Well, Node.js v14.3.0 was released with the support of top-level await! But we always had a flag to enabled top-level await on the REPL, ever since node v10!

The --experimental-repl-await enables experimental top-level await keyword support in REPL, so all you have to do is start the REPL with the flag node --experimental-repl-await and that's it.

And within the script you could do something like:

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// home.mjs
export function home() {
  return 'Hello home!';
}

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// index.mjs
const home = await import('./foo.mjs');
console.log(home());

You could execute this using node --experimental-top-level-await.

TLDR: For REPL we would need --experimental-repl-await and for mjs scripts --experimental-top-level-await as of today.