Type error on 1-1 relationships

I have the given (simplified) schema where User and Keychain have a 1-1 relationship:

datasource db {
  provider = "postgresql"
  url      = env("DATABASE_URI")
}

generator client {
  provider        = "prisma-client-js"
}

generator zod {
  provider      = "zod-prisma"
  output        = "./schemas"
  relationModel = true
}

model User {
  id       String    @id @default(uuid())
  keychain Keychain?
}

model Keychain {
  userID String @id
  owner  User   @relation(fields: [userID], references: [id])
}

Those relationships have to be defined as nullable on one end, but the generated user schema generates a TypeScript error:

import * as z from "zod"
import { CompleteKeychain, relatedKeychainSchema } from "./index"

export const userSchema = z.object({
  id: z.string()
})

export interface CompleteUser extends z.infer<typeof userSchema> {
  keychain: CompleteKeychain | null
}

/**
 * relatedUserSchema contains all relations on your model in addition to the scalars
 *
 * NOTE: Lazy required in case of potential circular dependencies within schema
 */
export const relatedUserSchema: z.ZodSchema<CompleteUser> = z.lazy(() => userSchema.extend({
  keychain: relatedKeychainSchema.nullish(), // <= ts2322
}))

Removing the .nullish() modifier for the keychain in relatedUserSchema fixes the issue.

Edit: using .nullable() there works too, which was what was used before.

[CarterGrimmeisen]

0.5.2 has been published with a fix for this.

[fergusmeiklejohn]

I’ve got this too. Replacing .nullish() with .nullable() in the related Models fixed the typescript error. It looks like its because it could be undefined