3.0.37+ breaks behavior of new keyword when accessing class under import

[kherock]

In a module that imports myExport from another module that has a class MyClass as a property, attempting to instantiate MyClass with

new myExport.MyClass()

can sometimes result it the error

[Error] TypeError: _d7e‍.t is not a constructor

It seems like this kind of transformation lost a set of parentheses and attempts to call the .t as a constructor.

in 3.0.36:

new (_6c5‍.t("myExport",myExport)).MyClass()

in 3.0.37:

new _e8e‍.t("myExport",myExport).MyClass()

I was really struggling to consistently reproduce this since there seems to be some caching happening that I'm not fully aware of. Sometimes the transformed result would remain as new myExport.MyClass(), but after resetting my shell session, it changes to be one of the above without even touching the source files.

Anyway, here's a pretty minimal reproduction that should help explain:

// index.js
import { myExport } from './module';

// the affected transformation only seems to happen with circular dependencies?
export default 'foo';

const fn = () => {
  new myExport.MyClass()
}

console.log(fn.toString());

// module.js
import foo from './index';
export const myExport = {
  MyClass: class MyClass { }
}

[jdalton]

Thanks @specialkk!

I've been tweaking the TDZ instrumentation and this got regressed.

[kherock]

I find it seriously impressive with how dedicated you are at keeping that issue counter down at 0. Do you ever find time to sleep?

Thanks for fixing these!

[jdalton]

v3.0.39 is released 🎉