"Virtual" modules in the compiler (Webpack + SWC, or TurboPack... once it has plugins)

[TomStrepsil]

Goals

1. The ability of plugin authors to generate virtual modules on-the-fly, as part of a plugin. Useful for meta-programming projects to enhance workflow.
2. The ability to redirect module requests to in-memory proxies

Non-Goals

1. Not fundamentally usurp the filesystem conventions of NextJs routers

Background

As per #44266, some webpack plugins utilise webpack-virtual-modules to provide plugin-generated code, perhaps proxying or transforming source files.

With the SWC compiler enabled, NextJs does not seem to support the idea. Despite the virtual modules setup appearing to work, the compiler will ultimately complain:

No such file or directory (os error 2)

With SWC disabled (via using a .babelrc), the virtual modules appear to be available.

It may be that the suggestion is best raised with SWC, but wondered if a plugin would be best owned by a webpack use-case?

N.B. Vite supports this concept natively: https://vite.dev/guide/api-plugin#importing-a-virtual-file

Proposal

Discovery or creation of a suitable SWC plugin, configured by NextJs to honour the WebPack InputFileSystem fully, even if virtualised.

[TomStrepsil]

N.B. Thanks to @larixer of @sysgears who has pointed out this shortcoming has been perhaps introduced by the optimisation introduced in #31685 via #31682.