How do I use custom scalars in mutations?

[reillyjodonnell]

I've dug through all of the examples, previous issues, and discussions and couldn't find a mention of it. What's the syntax for using custom scalars in mutations?

note: in these examples I'm using Prisma w/ the plugin

I've defined the type information in SchemaTypes generic parameter of the builder

export const builder = new SchemaBuilder<{
  Scalars: {
    Date: { Input: Date; Output: Date }
  }
  PrismaTypes: PrismaTypes
}>({
  plugins: [PrismaPlugin],
  prisma: {
    client: prisma,
  },
})

Then when creating the object schema the syntax is this:

builder.prismaObject('User', {
  fields: (t) => ({
    name: t.exposeString('name'),
    birthday: t.expose('birthday', {
      type: 'Date',
    }),
  }),
})

Now how do I use this custom scalar for mutations?

builder.mutationType({
  fields: (t) => ({
    createUser: t.prismaField({
      type: 'User',
      args: {
        name: t.arg.string({ required: true }),
        // birthday: t.arg ???
      },
      resolve: async (query, root, args, ctx, info) => {
        const create = await db.user.create({
          ...args,
          data: {
            name: args.name,
            // birthday: args.birthday,
          },
        })
      },
    }),
  }),
})

I really appreciate the help!

[hayes]

builder.mutationType({ fields: (t) => ({
  createUser: t.prismaField({
    type: 'User',
    args: {
      name: t.arg.string({ required: true }),
      birthday: t.arg({ type: 'Date' }),
    },
    resolve: ...