Strange import behavior with pdfjs v4

[dwickern]

Repro here: https://github.com/dwickern/ember-pdfjs-reproduction

In pdfjs v4 the project was converted to ESM. After upgrading pdfjs from v3 to v4, its default export is an unresolved promise:

To get it working, you actually have to await the imported module: https://github.com/dwickern/ember-pdfjs-reproduction/commit/f8aa137a5c9e858fa6dd293cfc00087c2f03dacc

Expected behavior: importing a module should resolve it

[dwickern]

There's a similar issue building with embroider, where the application route class is an unresolved promise:

Which manifests as an error:

Uncaught Error: Assertion Failed: Failed to create an instance of 'route:application'. Most likely an improperly defined class or an invalid module export.
    at assert (index.js:118:1)
    at InternalFactoryManager.create (index.js:372:1)
    at Proxy.create (index.js:204:1)
    at instantiateFactory (index.js:276:1)
    at lookup (index.js:223:1)
    at Container.lookup (index.js:121:1)
    at ApplicationInstance.lookup (container_proxy.js:19:1)
    at PrivateRouter.getRoute (router.js:183:1)
    at UnresolvedRouteInfoByParam.fetchRoute (router_js.js:714:1)
    at get route (router_js.js:648:1)

It seems that any module importing pdfjs will have its own exports broken. For example, in my app, a service imports pdfjs and all @service injections for that service are broken (they resolve to a Promise<Service> instead of the service).

Reproduction is on the embroider branch: https://github.com/dwickern/ember-pdfjs-reproduction/tree/embroider

[ef4]

The commentary in https://github.com/embroider-build/embroider/issues/1948#issuecomment-2135678186 also applies here.

And the same workaround should apply. The only difference is that for ember-auto-import you must make sure you opted in to dynamic import support.