?module should not 404

[akre54]

Hi there - I'm trying to load @tensorflow/tfjs as a module from unpkg. Adding the ?module flag correctly transpiles all of the import requests for all dependencies except for the package seedrandom. Visiting https://unpkg.com/seedrandom@2.4.4?module gets back a 404, which causes the whole import to fail. I feel like in this case ?module should just fall through to the un-transpiled version, correct?

I opened tensorflow/tfjs#4087 to bump the version, but I have to imagine this impacts other places too.

[j-f1]

As far as I know, unpkg does not do any transpiling besides altering the URLs of modules imported by an ES Module script. In this case, the seedrandom package does not provide an ES Module build (see davidbau/seedrandom#72) so there is no way to fix this without a new version of that package.

[akre54]

I guess I'm wondering why adding ?module should 404.

Shouldn't the default behavior be to serve the index package?

[j-f1]

That wouldn’t work. ?module will either output an ES Module file that can be used by native ES Module implementations, or 404. If it were to serve a CommonJS/AMD/etc module, it would result in clients getting an empty exports object, which is not useful.

[akre54]

Good point - I guess the only fix is to make all dependencies esm-aware, which kinda sucks.

I guess as a fallback this could rely on the global Math.seedrandom instead if the module fails, but it's probably not worth the hassle. Seems like the platform level needs to mature a bit more.