const AuthorType = new GraphQLObjectType({
  name: 'Author',
  description: 'Author data with related data',
  fields: () => ({
    id: { type: GraphQLInt },
    name: {
      type: GraphQLString,
      resolve: (source, args, context, info) => {
        if (info.fieldNodes?.[0].directives?.[0]?.name?.value === 'uppercase') {
          return source.name.toUpperCase();
        }
        return source.name;
      },
    },
  }),
});

query {
  user {
    name @uppercase
    lastname @uppercase
}