Turbopack: use ChunkGroupEntry::Shared, part 2 (#91279)
Followup to https://github.com/vercel/next.js/pull/90978, which fixed the `ChunkGroup`s passed to `.chunk_group()`, forgot to update the the module graph entry types, which didn't match up.
The `ChunkGroupEntry::Shared(ResolvedVc::upcast(*server_component))` one was more involved:
- We used to have `layout.js [app-rsc] (Next.js Server Component)` --ChunkingType::Shared--> `layout.js [app-rsc]` (the actual module)
- But this meant that the actual chunk group was `Shared(server_component.await?.module)` (the inner one)
- This wasn't possible to use for the module graph construction though, as the client reference transform needs to see the `layout.js [app-rsc] (Next.js Server Component)` module during the traversal, to infer the parent server component of the given subgraph.
So instead, move to
- `loader-tree in the template`
- --ChunkingType::Shared-->
- `layout.js [app-rsc] (Next.js Server Component)`
- --ChunkingType::Parallel-->
- `layout.js [app-rsc]`
The reason for that `ChunkingType::Shared` is so that we can chunk arbitrary modules that are loaded by `ChunkGroup::Entry`. Meaning that we can do `chunk_group(Shared(root_layout))).concat(chunk_group(Shared(layout))).concat(chunk_group(Entry(page)))` and rely on turbotask caching to deduplicate layout chunking across pages.
