The full schema for the GraphQL server tutorial

apollo-server-tutorial-schema.js

import { makeExecutableSchema } from 'graphql-tools';

const typeDefs = `
type Author {
  id: Int
  firstName: String
  lastName: String
  posts: [Post]
}
type Post {
  id: Int
  title: String
  text: String
  views: Int
  author: Author
}
type Query {
  author(firstName: String, lastName: String): Author
  getFortuneCookie: String
}
`;

export default makeExecutableSchema({ typeDefs });

Your blog tutorial references mocking data using the casual package, yet in this gist you removed the use of the addMockFunctionsToSchema function and importing your mocks to actually be able to do just that. Just a bit confusing for the reader since this seems like an oversight or a final version of the schema.