Typing is wrong in Fluent API on optional types when findUniqueOrThrow is used (null type becomes never)

[qortex]

Bug description

model Person {
  id       String @id

  optionalInfo OptionalInfo?
}

model OptionalInfos { ... }

Now, let's try to access optionalInfos on a Person we know exists:

const optInfo = await this.prisma.person
      .findUniqueOrThrow({ where: { id: existingId } })
      .optionalInfo();

Type of optInfo should be OptionalInfo | null. But it incorrectly is OptionalInfo.

Using findUnique to access Person instead of findUniqueOrThrow correctly implies typing is OptionalInfo | null.

This comes from the fact the the Null type in Prisma Client seems to be set for the topmost call and then cascade to the rest of the call. This is not correct behavior for the fluent API.

Related to, but not a duplicate of: #8929

How to reproduce

See Above

Expected behavior

In both cases, type should be OptionalInfo | null, or even OptionalInfo | null | undefined, to account for a Person not found.

Environment & setup

• OS: macOS
• Database: PostgreSQL
• Node.js version: 18

Prisma Version

prisma                  : 4.8.0
@prisma/client          : 4.8.0
Current platform        : darwin-arm64
Query Engine (Node-API) : libquery-engine d6e67a83f971b175a593ccc12e15c4a757f93ffe (at node_modules/@prisma/engines/libquery_engine-darwin-arm64.dylib.node)
Migration Engine        : migration-engine-cli d6e67a83f971b175a593ccc12e15c4a757f93ffe (at node_modules/@prisma/engines/migration-engine-darwin-arm64)
Introspection Engine    : introspection-core d6e67a83f971b175a593ccc12e15c4a757f93ffe (at node_modules/@prisma/engines/introspection-engine-darwin-arm64)
Format Binary           : prisma-fmt d6e67a83f971b175a593ccc12e15c4a757f93ffe (at node_modules/@prisma/engines/prisma-fmt-darwin-arm64)
Format Wasm             : @prisma/prisma-fmt-wasm 4.8.0-61.d6e67a83f971b175a593ccc12e15c4a757f93ffe
Default Engines Hash    : d6e67a83f971b175a593ccc12e15c4a757f93ffe
Studio                  : 0.479.0