Breaks with @babel/preset-env@7.4.3

[machty]

I wanted to make sure this issue didn't fall in the cracks, as I believe it nuked almost an entire day of work for me yesterday, and the way it fails is veeery subtle and tricky.

See here for references to this issue:

• Use default targets configuration for transpilation tests. emberjs/ember-cli-babel#284
• Failing Build emberjs/ember-cli-babel#281 (comment)

In short, there are combinations of values in config/target.js and the plugins added in @babel/preset-env@7.4.3 that will cause things like import EmberObject from '@ember/object' to be converted to an undefined _EmberObject instead of Ember.Object.

cc @chadhietala and @rwjblue

[lukemelia]

I have seen this as well. It is a tortuous experience.

[Leooo]

Same here. A massively tricky one to debug. Without @rwjblue 's help we could never have.

For now we reverted to using

/* eslint-env node */
module.exports = {
  browsers: [
    'ie 9',
    'last 1 Chrome versions',
    'last 1 Firefox versions',
    'last 1 Safari versions'
  ]
};

in our config/target.js

from

/* eslint-env node */
module.exports = {
  browsers: [
    'last 1 version',
    '> 2% in GB'
  ]
};

but obviously not ideal so happy to follow the resolution on this.

[raido]

I recently ran into same thing and @rwjblue pointed me here.

Reference issue I opened over here:

emberjs/ember-cli-babel#316

[raido]

@rwjblue any hope of this getting some attention?

I tried to debug to some extent it by linking this package locally, but did not manage to find where exactly transformations break.

[rwjblue]

The fix for this is basically the same as what was done in ember-data/babel-plugin-ember-data-packages-polyfill#3

[rwjblue]

This seemed to crop up again when running Babel 7.10.0+ (released 2020-05-25). I'm looking into fixing (based on my last comment).

[runspired]

@rwjblue I have time this afternoon if needed to supply a fix

[rwjblue]

Thanks @runspired, definitely will appreciate the help (either in reviews or impl).

After a bunch of general repo cleanup, I've reproduced the failures being reported in #108.

[rwjblue]

ember-cli-babel@7.20.1 was just released, and should fix the underlying issue.

https://github.com/babel/ember-cli-babel/releases/tag/v7.20.1