However note that ESM in Node comes with drawbacks that prevent end-users from relying them in various situations. Those will be mostly solved once loaders become stable, but until then it's still advised to ship packages as both CJS and ESM.
https://github.com/arcanis/clipanion/blob/master/rollup.conf...
For example to use `require` inside ESModules you would do:
```mjs import { createRequire } from 'module'; const require = createRequire(import.meta.url); require('./whatever-in-cjs'); ```
There is a reason this isn't "by default" though since ESM doesn't "silently" interop with CJS to not make writing universal code harder.