Copy getters and setters correctly in interopWildcard

[danez]

Q	A
Fixed Issues?	Fixes #4290 Fixes #5790
Patch: Bug Fix?	y
Major: Breaking Change?	n?
Minor: New Feature?
Tests Added + Pass?	Yes
Documentation PR
Any Dependency Changes?
License	MIT

This ensures that getters and setters are copied correctly in the interopRequireWildcard helper.

[Andarist]

maybe we should add an additional loose helper without that logic later?

[nicolo-ribaudo]

Does this also influence import *? If yes, can you add a test for it?

e.g.

import * as foo from "./foo";
assert.throws(() => foo.bar);

// foo.js
module.exports = {
  get bar() { throw {} }
};

[danez]

Good idea, I added it.

[babel-bot]

Build successful! You can test your changes in the REPL here: https://babeljs.io/repl/build/5915/

[loganfsmyth]

I think if we're going to do this, we should check for the existence of Object.defineProperty, or we should finally expose a flag for modules to opt in or out of Object.defineProperty usage. Otherwise this is going to make things unusable for people targeting old environments.

[danez]

I will add a check for Object.defineProperty, which I think should be enough here, because when Object.defineProperty is not there then getters and setters are also not supported.

It is basically supported in all environments besides IE8 and older. But IE8 is also over 10years old now. 🕵️‍♀️
What if we change in babel 7 and state that generated code from babel needs at least ES5, like react does now (they even require Map and Set). Would be nice to have statistics to see what environments people support, but I guess that does not really exist. Or did we have already complains about this?

[danez]

And core-js also has a polyfill for it, so we could also link people there. And from my experience if you support IE8 or older, then you need polyfills anyway.