Setup server side

add gen script to your package.json file

{
   "scripts": {
      "gen": "node ./node_modules/nodejs-react-typescript--graphql-code-generator --server --dist='./src/generated' --if='../interface'",
   },
}

where: --server - means generate server code; --dist - where generated code will be located; --if - path to folder with your interfaces IQuery.ts IMutation.ts ISubscription.ts;

add server.ts file

import {resolvers} from './generated/resolvers';
import {typeDefs} from './generated/mergedGQLSchemas';
import http from 'http';

const express = require('express');
const { ApolloServer } = require('apollo-server-express');

const PORT = 4001;

const app = express();

const server = new ApolloServer({
   typeDefs,
   resolvers,
});

server.applyMiddleware({
   app
});

const httpServer = http.createServer(app);
server.installSubscriptionHandlers(httpServer);

httpServer.listen(PORT, () => {
  console.log(`🚀 server ready at http://localhost:${PORT}${server.graphqlPath}`);
  console.log(`🚀 Subscriptions ready at ws://localhost:${PORT}${server.subscriptionsPath}`);
});

THAN RUN NEXT USUAL COMMANDS

npm run gen
npm run build
npm run start

Setup client side

add gen script to your package.json file

{
   "scripts": {
      "gen": "node ./node_modules/nodejs-react-typescript--graphql-code-generator --client --dist='./src/generated' --if='../interface'",
   },
}

where: --client - means generate client code; --dist - where generated code will be located; --if - path to folder with your interfaces IQuery.ts IMutation.ts ISubscription.ts;

THAN RUN NEXT USUAL COMMANDS

npm run gen
npm run build
npm run start

Simple usage use-case IQuery

This code generator generates all server and client side code. You need just to specify interface for communication in typescript style. Create file IQuery.ts in interfaces folder with the following content:

interface IUser {
   id: string;
   name: string;
   age: number;
}
interface IShortProject {
   id: string;
   name: string;
}
interface IProject {
   id: string;
   name: string;
   users: IUser[];
   user: (id: string) => IUser;
}
interface IAccount {
   project: (id: string) => IProject|IShortProject;
   projects: IShortProject[];
}
interface IQuery {
   account: (token: string) => IAccount;
}

Run code generation

npm run gen

Than you will have next requests to use

// all generated code will be here in the generated folder
import {query} from "./generated/query.requests";
import {IAccount, IUser} from "./generated/query.interfaces";
import {IProject} from "./generated/query.interfaces";
import {IShortProject} from "./generated/query.interfaces";

class SomeComponent extends React.Component<any, any> {

   // this method shows that not all generated requests you will want to use
   fetchWholeAccount = async () => {
      const accountToken = 'some token';
      const projectId = 'some id';
      const userId = 'some id';

      // I see no one case where you will need to fetch all account data, 
      // but anywhere this function will be available in the generated code

      const account: IAccount = await query.account(accountToken).fetchIAccount(projectId, userId);
      console.log(account.project);
      console.log(account.project.user.id);
      console.log(account.project.user.name);
      console.log(account.project.user.age);

      account.project.users.map((user: IUser) => {
         console.log(`here will be available all IUser fields ${user.id} ${user.name} ${user.age}`);
      });

      account.projects.map((prj: IShortProject) => {
         console.log(`here will be available only two fields from IShortProject interfaces ${prj.id} ${prj.name}`);
      });
   };

   // this method shows that you can define short interfaces if you want fetch not all data from node
   fetchShortProject = async () => {
      const accountToken = 'some token';
      const projectId = 'some id';

      const shortProject: IShortProject = await query.account(accountToken).project(projectId).fetchIShortProject();
      console.log(shortProject.id);
      console.log(shortProject.name);
   };

   // this method shows that not all generated requests you will want to use
   fetchProject = async () => {
      const accountToken = 'some token';
      const projectId = 'some id';
      const userId = 'some id';

      // this call also not useful, because it is same situation with fetching all account data
      // too math data will be fetched and then available
      const project: IProject = await query.account(accountToken).project(projectId).fetchIProject(userId);
      console.log(project);
      console.log(project.user.id);
      console.log(project.user.name);
      console.log(project.user.age);

      project.users.map((user: IUser) => {
         console.log(`here will be available all IUser fields ${user.id} ${user.name} ${user.age}`);
      });
   };

   // this method shows how to fetch concrete user data
   fetchShortProjects = async () => {
      const accountToken = 'some token';

      const projects: IShortProject[] = await query.account(accountToken).projects().fetchArrayIShortProject();
      projects.map((prj: IShortProject) => {
         console.log(`here will be available only two fields from IShortProject interfaces ${prj.id} ${prj.name}`);
      });
   };

   // this method shows how to fetch concrete user data
   fetchUser = async () => {
      const accountToken = 'some token';
      const projectId = 'some id';
      const userId = 'some id';

      const user: IUser = await query.account(accountToken).project(projectId).user(userId).fetchIUser();
      console.log(user.id);
      console.log(user.name);
      console.log(user.age);
   };

   // this method shows how to fetch all users
   fetchUsers = async () => {
      const accountToken = 'some token';
      const projectId = 'some id';
      const userId = 'some id';

      const users: IUser[] = await query.account(accountToken).project(projectId).users().fetchArrayIUser();
      users.map((user: IUser) => {
         console.log(`here will be available all IUser fields ${user.id} ${user.name} ${user.age}`);
      });
   };
}