type-graphql: How to know which fields are returned by Resolver

I am writing a backend application that uses type-graphql. The GraphQL schema includes a Folder type that looks like this:

type Folder {
  id: ID!
  name: String!
  rules: [Rule!]!
  parent: Group

Rule and Group are other types.

My Resolver defines a Query called folders that returns all Folders:

import {Query, Resolver} from 'type-graphql'

@Resolver(() => Folder)
export default class FolderResolver {

  @Query(() => [Folder])
  folders(): Promise<Folder[]> {
    // query db and return results

To query the folders, their rules, and their parent group from the database, I have to join the database tables and return the joined result, which works without problems. However: If the rules field and / or the parent field was not requested in the GraphQL query, I could omit the joins and make the database query much more efficient. So the fields that were requested in the GraphQL query have a definite effect on the logic that I need to execute, but I don't see a way of finding out which fields were requested inside the folders function.

When a Query in a type-graphql Resolver is executed, is there a way to determine which fields were requested in the GraphQL query?

Read more here: https://stackoverflow.com/questions/65720312/type-graphql-how-to-know-which-fields-are-returned-by-resolver

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