How do you correctly type helper functions to share fields between Prisma objects?

[oliverbaseimmune]

For example if you have models that often expose the same fields like the following:

// `Date` is registered as a global scalar on the schema
builder.prismaObject('SomeModel', {
  fields: (t) => ({
    // ...
    createdAt: t.expose('createdAt', {
      type: 'Date',
    }),
    updatedAt: t.expose('updatedAt', {
      type: 'Date',
    }),
    // ...
})

It is possible to create a helper exactly as described in the documentation but it does not work if you try to use PrismaObjectRef and builder.prismaObjectFields:

function addCommonFields(
  ref: PrismaObjectRef<
    TypesWithDefaults,
    PrismaModelTypes,
    { createdAt: Date; updatedAt: Date }
  >,
) {
  builder.prismaObjectFields(ref, (t) => ({
    createdAt: t.expose('createdAt', { // Argument of type 'string' is not assignable to parameter of type 'never'
      type: 'Date',
    }),
    updatedAt: t.expose('updatedAt', { // Argument of type 'string' is not assignable to parameter of type 'never'
      type: 'Date',
    }),
  }))
}

Does anyone know what I'm doing wrong with this implementation?

I went down this rabbit hole because it seemed like it would be possible (and quite useful) that instead of using a helper function after declaring the model, you could instead convert the helper to take t: PrismaObjectFieldBuilder and just spread the return from a helper like this:

function addCommonFields(
  t: PothosSchemaTypes.PrismaObjectFieldBuilder<
    TypesWithDefaults,
    PrismaModelTypes,
    { createdAt: Date; updatedAt: Date }
  >,
) {
  return {
    createdAt: t.expose('createdAt', { // Argument of type 'string' is not assignable to parameter of type 'never'
      type: 'Date',
    }),
    updatedAt: t.expose('updatedAt', { // Argument of type 'string' is not assignable to parameter of type 'never'
      type: 'Date',
    }),
  }
}

builder.prismaObject('SomeModel', {
  fields: (t) => ({
    // ...
    ...addCommonFields(t), // Types of property 'relation' are incompatible
    // ...
})

However, this presents new errors with incompatibilities between relation, or exposeBoolean if I import PrismaObjectFieldBuilder from the plugin directly vs. using PothosSchemaTypes.PrismaObjectFieldBuilder.

Any tips would be greatly appreciated!