Set ERR_PACKAGE_PATH_NOT_EXPORTED code on errors when bailing

Node throws an ERR_PACKAGE_PATH_NOT_EXPORTED error when “Package exports do not define or permit a target subpath in the package for the given module”.

For improved compatibility with the Node ecosystem, I think it would be a good idea for resolve.exports to set error.code to ERR_PACKAGE_PATH_NOT_EXPORTED when bailing, so that packages can continue checking the error code to tell “path not exported” errors apart from other errors.

Ref:

• https://nodejs.org/api/esm.html#esm_resolver_algorithm
• https://github.com/nodejs/node/blob/2af43f65055de2817eb7907d3a3d3b3a3de127f5/lib/internal/modules/esm/resolve.js#L321

[developit]

I think this would be nice. Given that this package is mostly used in cli/tooling/server environments, it feels like it’s worth the extra bytes. It provides for a potential future scenario where resolve() throws an error for some other reason (malformed map key, invalid path value, etc).

For a library, it’d be preferable to avoid subclassing Error though. Just something like Object.assign(Error('xyz'), { code: 'ERR_PACKAGE_PATH_NOT_EXPORTED' }) feels like enough.

[lukeed]

Thanks! Right, I would just add a code key instead of throwing custom error types.

@paul-soporan already raised #5 for throwing on invalid target(s), but I don’t think resolve() is the right time/place for that. I don’t see this as an "exports" validator utility.