Nested default includes lose scalar result inference in rc.8

[JoeRoddy]

Type: type inference bug. Target: prisma/orm SQL ORM client.

Run npm run typecheck in the standalone reproduction. include-types.ts compares these native queries over its generated contract:

native.orm.public.Post.include("comments", c => c.include("author")).first();
native.orm.public.Post.include("comments", c =>
  c.select("id").include("author", a => a.select("id"))
).first();

The first query's comment id is inferred as unknown; assigning it to string | undefined fails. Explicitly selecting the same nested scalar preserves string | undefined. Both paths should retain the generated schema's field types, including when selection is implicit. The reproduction's @ts-expect-error records the native defect and should become unused when fixed. No type cast or authorization-adapter import is involved.

Relevant regression coverage includes default and explicit root/nested selections, optional and required to-one includes, multiple to-many nesting levels, scalar codecs, nullable fields, and include reducers. This report is limited to default-selection inference loss.

Primary source: ORM types, collection.

Environment

• @prisma/orm-postgres: 8.0.0-rc.8 (the live latest tag when reverified September 6, 2026)
• Prisma CLI: 8.0.0-rc.13
• TypeScript: 5.9.3
• Node: 26.5.0
• npm: 11.17.0
• OS: macOS 26.6.2 arm64
• PostgreSQL: 14.23 for database-backed cases