This is the source of the vendor library, as you can see there is a demo.component file which should have a ngfactory file created
However after running ngc on this repo npm run ngc, only the NgModule is codegen'd, as the component is not exported from the 3rd party module.
There is no error message from ngc that the component could not be codegen'd, but there should be.
If the component is exported from the library's main/module file then ngc picks it up and will codegen it correctly
