nextjs with async library demo

Problem

I need a library to be accessible from Node on the server-side and from NextJS React pages.

I would like to take advantage of the new async/await syntax because it makes the code remarkably cleaner and easier to debug.

Bug

This demo shows weirdness when trying to include a JavaScript library with async functions inside of a NextJS page:

$ yarn install
$ yarn exec next
 WARNING  Compiled with 2 warnings

 warning  in ./pages/index.js

24:18-21 "export 'foo' was not found in '../lib/test'

 warning  in ./pages/index.js

24:62-65 "export 'foo' was not found in '../lib/test'

TypeError: Cannot assign to read only property 'exports' of object '#<Object>'
...

And visiting http://localhost:3000 --

I can't change lib/test.js to ES6-style exports because Node will complain with SyntaxError: Unexpected token. What am I doing wrong?

Versions

NextJS 5.1
Node 9.11.1

Related issues

pages/index.js

import { foo } from '../lib/test'

export default () => <div>hello {String(typeof foo)}</div>

lib/test.js

async function foo () {}

module.exports = { foo }