GraphQL Reason server

GraphqlServer.re

open Lwt.Infix;
open Graphql_lwt;

type role =
  | User
  | Admin;

type user = {
  id: int,
  name: string,
  role,
  friends: list(user),
};

let rec alice = {id: 1, name: "Alice", role: Admin, friends: [bob]}
and bob = {id: 2, name: "Bob", role: User, friends: [alice]};

let users = [alice, bob];

let role =
  Schema.(
    enum(
      "role",
      ~values=[
        enum_value("USER", ~value=User, ~doc="A regular user"),
        enum_value("ADMIN", ~value=Admin, ~doc="An admin user"),
      ],
    )
  );

let user =
  Schema.(
    obj("user", ~fields=user =>
      [
        field("id", ~args=Arg.[], ~typ=non_null(int), ~resolve=(_, p) =>
          p.id
        ),
        field("name", ~args=Arg.[], ~typ=non_null(string), ~resolve=(_, p) =>
          p.name
        ),
        field("role", ~args=Arg.[], ~typ=non_null(role), ~resolve=(_, p) =>
          p.role
        ),
        field(
          "friends",
          ~args=Arg.[],
          ~typ=list(non_null(user)),
          ~resolve=(_, p) =>
          Some(p.friends)
        ),
      ]
    )
  );