[Bug]: Typegen doesn't support `id` db fields without a default value

[Tobbe]

What's not working?

This is the generated code:

export const createUnit: MutationResolvers['createUnit'] = ({ input }) => {
  return db.unit.create({
    data: input,
  })
}

data gets red squiggles.

To dig a bit deeper in what's wrong you can do this to get better type info

type CreateUnitInput = Parameters<MutationResolvers['createUnit']>[0]['input']

export const createUnitCustom: MutationResolvers['createUnit'] = ({
  input,
}: {
  input: CreateUnitInput
}) => {

What Prisma is expecting is this:

  /**
   * Unit create
   */
  export type UnitCreateArgs<ExtArgs extends $Extensions.InternalArgs = $Extensions.DefaultArgs> = {
    /**
     * Select specific fields to fetch from the Unit
     */
    select?: UnitSelect<ExtArgs> | null
    /**
     * Choose, which related nodes to fetch as well
     */
    include?: UnitInclude<ExtArgs> | null
    /**
     * The data needed to create a Unit.
     */
    data: XOR<UnitCreateInput, UnitUncheckedCreateInput>
  }

Especially data is interesting. It wants either UnitCreateInput xor UnitUncheckedCreateInput

And that's not what our generated types are.

How do we reproduce the bug?

I haven't created a minimal reproduction yet, but you at least need two prisma models where one model has a relation to the other. I don't know if there are more specific requirements than that to trigger the bug.

This might be enough of my schema to trigger the issue

model Unit {
  id           String        @id
  createdAt    DateTime      @default(now())
  updatedAt    DateTime      @updatedAt
  name         String
  restaurant   Restaurant    @relation(fields: [restaurantId], references: [id])
  restaurantId String
}

model Restaurant {
  id                String          @id @default(cuid())
  createdAt         DateTime        @default(now())
  updatedAt         DateTime        @updatedAt
  name              String
  units             Unit[]
}

What's your environment? (If it applies)

yarn rw info

  System:
    OS: macOS 15.2
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 22.14.0 - /private/var/folders/7j/9p56mwmj6jsfdr2h5_884j9w0000gn/T/xfs-75cb72c7/node
    Yarn: 4.4.0 - /private/var/folders/7j/9p56mwmj6jsfdr2h5_884j9w0000gn/T/xfs-75cb72c7/yarn
  Databases:
    SQLite: 3.43.2 - /usr/bin/sqlite3
  Browsers:
    Safari: 18.2
  npmPackages:
    @redwoodjs/auth-dbauth-setup: 8.2.0 => 8.2.0
    @redwoodjs/core: 8.2.0 => 8.2.0
    @redwoodjs/project-config: 8.2.0 => 8.2.0
  redwood.toml:
    [web]
      title = "Victory"
      port = 8910
      apiUrl = "/.redwood/functions"
      includeEnvironmentVariables = [
        # Add any ENV vars that should be available to the web side to this array
        # See https://redwoodjs.com/docs/environment-variables#web
      ]
    [api]
      port = 8911
    [browser]
      open = true
    [notifications]
      versionUpdates = ["latest"]
    [generate]
      tests = false
      stories = false

Are you interested in working on this?

• I'm interested in working on this

[Tobbe]

Looking closer at the type RW currently generates I see this

scrolling down...

So we have restaurantId: Scalars["String"];

That means we want Prisma's type to resolve to the UnitUncheckedCreateInput type but for some reason it's not doing that.
Haven't figured out why yet.

The type we're generating is missing id! Weird 🤔

Updating the destructured type to this gets rid of the red squiggles

type CreateUnitInput = Parameters<
  MutationResolvers['createUnit']
>[0]['input'] & { id: string }

[Tobbe]

I think I figured it out. I haven't verified this yet, but I guess we assume that id is autogenerated, and thus should not be supplied when doing "create". Or at least that it's optional. Which, if you look at my model, it isn't.

[Tobbe]

Confirmed that updating my prisma model to have this solved the red squiggle problem.

id           String        @id @default(uuid())

The issue is still valid though. We could do a better job generating our types to support ids with no default value