Tests for top-level await with circular module import

[theoludwig]

Repo: https://github.com/tc39/proposal-top-level-await/ Spec text: https://tc39.github.io/proposal-top-level-await/ ECMA-262 PR: https://github.com/tc39/ecma262/pull/2408

In the Google Chrome v129 release, the JavaScript module import is broken with circular + top-level-await (discovered by @antfu). Related:

• https://github.com/antfu/repro-chrome-v129
• https://x.com/antfu7/status/1836846357489012816

To avoid other engines or implementers to also break accidentally this feature, or even for Google Chrome to avoid breaking it again, it would be great to add tests for this in Test262 (as suggested here: https://x.com/robpalmer2/status/1836846820418601384).

Demonstration

Online demo

When the entry file is foo.js, with the following content:

// bar.js
import { define } from './foo.js'

export default define('It works!')

// foo.js
export function define(foo) {
  return foo.toUpperCase()
}

const getter = () => import('./bar.js')

await 1

getter()
  .then(r => {
    // this will never be resolved
  })
  .catch(e => {
    // this either
  })

Note that if remove the await 1, it will work again.

[nicolo-ribaudo]

Tests have been a used in https://github.com/tc39/test262/pull/4116. Would you like to open a PR to move it out of the staging directory?

[theoludwig]

Tests have been a used in #4116. Would you like to open a PR to move it out of the staging directory?

@nicolo-ribaudo Sure! :smile: PR opened: #4262