Resolve accompanies to just the original import id

[klaftertief]

Maybe I misunderstood how combining multiple main files worked, at least I could not make it work for our use-case.
I really love how the feature is used by just adding multiple Elm modules as query params, this makes it super flexible.

We have four different Elm apps which should be compiled into one bundle. There are four different JS modules that import the combined Elm apps individually. So index-a.js, index-b and so on each import A.elm?with=B.elm&with=C.elm&with=D.elm. This is simplified, as the JS and Elm entry points might live at different directory levels. It worked at some cases, but adding the fourth Elm module to the list made it break. I believe this was caused by setting a wrong importer when walking the import tree in the original implementation. I do not know a lot about Vite's or Rollup's internals, but it made me wonder if it is actually needed.

In this PR I made it such that the path in each with param is relative to the originally required Elm module, A.elm in this case. So in the implementation I use a simple path.resolve to add each accompany to the list of compilable Elm modules. It is much simpler and is something I can understand. But I also have a feeling I'm missing something in the original implementation.

[hmsk]

Uh, looks really simpler! However, we need to rely on plugin context to resolve importing. The relative path may include some alias or magic words to work with other plugins.

But I'm curious about the problem you faced originally. Can you give me an easier way to reproduce that situation?

[klaftertief]

Thanks for the quick response. I'll see if I can spin up a SSCCE...

Good to know about the context to resolve imports. But does it really apply to Elm modules? The path/id of the original Elm module (as imported from JS) is not touched, everything with-based is just handled by the Elm compiler and based on the original Elm module.

The relative path may include some alias or magic words to work with other plugins.

Can you give an example here?

[hmsk]

what if vite's config has alias setting like:

  resolve:{
    alias:{
      '@' : path.resolve(__dirname, './src')
    },
  },

We'd expect import { Elm } from '@/Description.elm?with=@/AnotherDescription.elm' works.

[klaftertief]

Thanks, yes, this would totally not work with this PR :-)
Converting it to a draft.