Cannot transpile yield/await spread for Firefox 47

[boris-petrov]

Bug Report

Current behavior

• REPL

import Component from '@glimmer/component';
import intersection from 'lodash/intersection';

export default class FooComponent extends Component {
  async foo() {
    intersection(...(await Promise.all([])));
  }
}

Expected behavior
Code to be transpiled correctly.

Currently Babel blows up with:

Expected type "Expression" with option undefined, but instead got "SpreadElement".

Using firefox 35 for targets works. As does firefox 53 and above.

[babel-bot]

Hey @boris-petrov! We really appreciate you taking the time to report an issue. The collaborators on this project attempt to help as many people as possible, but we're a limited number of volunteers, so it's possible this won't be addressed swiftly.

If you need any help, or just have general Babel or JavaScript questions, we have a vibrant Slack community that typically always has someone willing to help. You can sign-up here for an invite."

[nicolo-ribaudo]

Minimal reproduction:

function *foo() {
  intersection(...yield);
}

EDIT: This is probably facebook/regenerator#397. A fix would probably be similar to facebook/regenerator#385, if anyone wants to help.

[nicolo-ribaudo]

Closing as tracked at facebook/regenerator#397