GraphQL.js

From https://graphql.org/graphql-js/constructing-types/

var express = require("express");
var { graphqlHTTP } = require("express-graphql");
var graphql = require("graphql");

// Maps id to User object
var fakeDatabase = {
  a: { id: "a", name: "alice" },
  b: { id: "b", name: "bob" },
};

// Define the User type
var userType = new graphql.GraphQLObjectType({
  name: "User",
  fields: {
    id: { type: graphql.GraphQLString },
    name: { type: graphql.GraphQLString },
  },
});

// Define the Query type
var queryType = new graphql.GraphQLObjectType({
  name: "Query",
  fields: {
    user: {
      type: userType,
      // `args` describes the arguments that the `user` query accepts
      args: {
        id: { type: graphql.GraphQLString },
      },
      resolve: (_, { id }) => {
        return fakeDatabase[id];
      },
    },
  },
});

var schema = new graphql.GraphQLSchema({ query: queryType });

var app = express();
app.use(
  "/graphql",
  graphqlHTTP({
    schema: schema,
    graphiql: true,
  }),
);
app.listen(4000);
console.log("Running a GraphQL API server at localhost:4000/graphql");

Grats

import express from "express";
import { graphqlHTTP } from "express-graphql";
import { getSchema } from "./schema"; // Generated by Grats

// Maps id to User object
var fakeDatabase = {
  a: { id: "a", name: "alice" },
  b: { id: "b", name: "bob" },
};

/** @gqlType */
type User = {
  /** @gqlField */
  id: string;
  /** @gqlField */
  name: string;
};

/** @gqlType */
type Query = unknown;

/** @gqlField */
export function user(_: Query, args: { id: string }): User {
  return fakeDatabase[args.id];
}

var app = express();
app.use(
  "/graphql",
  graphqlHTTP({
    schema: getSchema(),
    graphiql: true,
  }),
);
app.listen(4000);
console.log("Running a GraphQL API server at localhost:4000/graphql");

Playground