jest-worker: should not expose `.default` babel interop

[ljharb]

import a from 'jest-worker' of course, works fine, because it's using babel on both ends.

However, const b = require('jest-worker') results in a !== b, and to get at the proper value, you need to do b.default.

Entry points should not expose babel interop details like .default - can https://github.com/facebook/jest/blob/master/packages/jest-worker/src/index.js use module.exports = instead of export default (or can you use the add-module-exports transform?

[SimenB]

add-module-exports sounds good to me, I agree it's annoying having to do .default in node (and probably not good for real ESM support in node).

PR welcome! 😀

[felippenardi]

@SimenB Here is a proposal: #5811

[SimenB]

See comment in PR

[ljharb]

After a year with an open PR, i think this is a really user-hostile decision.

[SimenB]

The PR didn't work properly. Using the plugin was discussed a bit in #7554 and it seems like people have been burnt by add-module-exports before. And e.g. Babel itself removed it for their 7 release.

[ljharb]

There’s lots of alternatives including a manual entry point that does the un-.defaulting.

As for Babel themselves, it’s reasonable for Babel to expect consumers to couple to Babel interop, it’s not reasonable for “not Babel” to do so.

[SimenB]

Yeah, that's an option. Do you know if that would still work for people doing import? I guess we could do module.exports = require('./build/index'); (unpacking the default in some way) and as long as types in package.json still pointed to build/index.d.ts it would work?

[ljharb]

Yes, it would work for both.