Add support for an arg to be based on a Type at the data layer while constructing Queries & Mutations

[robin-macpherson]

Perceived Problem

• There is currently no support for an arg to be based on a type at the data layer while constructing a Query or Mutation in our GraphQL API.

Example:
Let's say we have a Post type that has a status field to indicate whether a Post is PUBLISHED or a DRAFT, expressed with an enum, PostStatus, like so:

model Post {
  Id
  ...
  status   PostStatus @default(DRAFT)
}
enum PostStatus {
  DRAFT PUBLISHED
}

We should be able to then write a Query where we can take in an arg that will be based on the PostStatus enum in order to filter DRAFT or PUBLISHED posts. Currently, we can only use scalar types for this, so have to do something like:

t.list.field('feed', {
  type: 'Post',
  args: {
    Published: schema.booleanArg(),
  },
  resolve: async (parent, args, ctx) => {
    return ctx.db.post.findMany({
      where: {
         Published: args.Published,
      },
   })
 },
})

Ideas / Proposed Solution(s)

• For now, my workaround is to simply pass a String as an argument that maps to the enum values.
• It would be great if instead of only schema.stringArg() we could do something like schema.type('PostStatus') for example.

[Weakky]

Hey @robin-macpherson, sorry for the late response. You can use schema.arg({ type: 'PostStatus' }) to do exactly what you're looking for 🙌