Unable to use ESM import

I’m seeing errors when importing the module into an ESM project:

import { kml } from '@tmcw/togeojson';
         ^^^
SyntaxError: Named export 'kml' not found. The requested module '@tmcw/togeojson' is a CommonJS module, which may not support all module.exports as named exports.

But if I use this method:

import toGeoJSON from '@tmcw/togeojson';

I see this error:

export { gpx, gpxGen, kml, kmlGen, kmlWithFolders, tcx, tcxGen };
^^^^^^

SyntaxError: Unexpected token 'export'

So I’m kinda stuck. Any idea what’s happening here? Using v5.1.2

[tmcw]

v5.1.3 released with a fix. Changing file endings for the export from .js to .mjs enables Node.js native ESM support without changing everything else. Thanks for the bug report!

[neave]

The fix seems to be to also add "type": "module" to togeojson’s package.json

Yes that could fix this issue, but based on https://github.com/placemark/togeojson/issues/63#issuecomment-1061252314 it may not be that simple:

Okay, it was the type: "module" field, which opens a real can of worms. Introduced 4.6.1, which renames main to .cjs and adds an export field in package.json to direct users to that.