Receiving type-checking error from root query based on the type I assign to my root nodes. GraphQL, TypeScript. Express

Question

I'm pretty new to typescript/graphql world and I am receiving a strange error when I am defining the type of one of my root nodes. The root node I am implementing simply returns a user by ID in the resolve function and therefore, I am populating the 'type' key with UserType I've created. However, I get an error from typescript indicating

fields: Thunk<GraphQLFieldConfigMap<TSource, TContext>>;
              ~~~~~~
        The expected type comes from property 'fields' which is declared here on type 'Readonly<GraphQLObjectTypeConfig<any, any>>'

rootQuery.ts file:

import mongoose from "mongoose";
import { GraphQLObjectType, GraphQLString } from "graphql";

const UserType = "./user_type.ts";
const User = mongoose.model("user");

const RootQueryType = new GraphQLObjectType({
  name: "RootQueryType",
  fields: () => ({
    getUserById: {
      type: UserType,
      args: {
        id: { type: GraphQLString },
      },
      async resolve(_, { id }) {
        try {
          return await User.findById(id);
        } catch (err) {
          console.error(err.message);
        }
      },
    },
  }),
});

module.exports = RootQueryType;

user_type.ts file:

import { GraphQLObjectType, GraphQLString, GraphQLList } from 'graphql'

const UserType = new GraphQLObjectType({
    name: 'User',
    fields: () => ({
        name: { type: GraphQLString },
        email: { type: GraphQLString },
        password: { type: GraphQLString },
        language: { type: GraphQLString },
        topics: { type: new GraphQLList(GraphQLString)}
    })
})

module.exports = UserType;

The error is pointing at the "fields" key in the RootQueryType. When I replace the value of the 'type' key in the 'getUserById' node with 'GraphQLString', the errors goes away. But clearly that's not what I want since the returning value will be referenced to the UserType.

Thanks for your time.

Answer 1

I found that it was the way I was importing/requiring the graphql package in my rootQuery.ts file. Instead of importing, I changed it to:

const graphql = require('graphql')
const { GraphQLObjectType, GraphQLString } = graphql;

But I am not understanding why. How does require compare to import so much that it causes errors?