with Mutations

resolvers.js

import mongoose from 'mongoose'
import authorModel from './models/author'


const resolvers = {
  Query: {
    authors: () => {
      return authors
    },
    author: (root, args) => {
      const id = args.id;
      return authors.find(author => author.id === id);
    }
  },
  Mutation: {
    addAuthor: (root, {name, age, Books}) => {
      const author = new authorModel({name, age, Books})
      return author.save()
    }
  }
}

export default resolvers;