Importing named exports from CJS `.ts` files in `.mts` files does not work

[sapphi-red]

Acknowledgements

• I read the documentation and searched existing issues to avoid duplicates
• I understand this is a bug tracker and anything other than a proven bug will be closed
• I understand this is a free project and relies on community contributions
• I read and understood the Contribution guide

Minimal reproduction URL

https://stackblitz.com/edit/node-nfzer8?file=index.mts

Problem & expected behavior (under 200 words)

This works with Node 20.18.0. This does not work with Node 18.20.4 and 22.11.0. I'm not sure if you expect this to work or not to work.

Bugs are expected to be fixed by those affected by it

• I'm interested in working on this issue

Compensating engineering work will speed up resolution and support the project

• I'm willing to offer $10 for financial support

[michaelfaith]

We're seeing this as well, but not just for mts files. Also for ts files within packages that have type: module. And only after updating from v20 to v22

SyntaxError: The requested module '@p/our' does not provide an export named 'findRoot'

[jamesarosen]

With the above StackBlitz app,

❯ pnpm tsx -e "import('./foo.ts').then(console.log)"
[Module: null prototype] { default: { defineConfig: [Getter] } }

TSX is causing all named exports to be wrapped up into the default export.

It seems to be a problem with the compilation phase. It doesn't happen with dynamic imports that are already JS:

❯ pnpx tsx -e "import('fs').then(fs => console.log(fs.readFileSync))"
[Function: readFileSync]

It also doesn't happen with static imports of TS:

❯ pnpx tsx -e "import { defineConfig } from './foo.ts'; console.log(defineConfig)"
[Function: defineConfig]