schema.js

import {
  GraphQLObjectType,
  GraphQLInt,
  GraphQLString,
  GraphQLList,
  GraphQLSchema,
  GraphQLNonNull
} from 'graphql';
import Db from './db'

const Person = new GraphQLObjectType({
  name: 'Person',
  description: 'This represents a Person',
  fields: () =>{
    return{
      id:{
        type: GraphQLInt,
        resolve(person){
          return person.id;
        }
      },
      firstName:{
        type: GraphQLString,
        resolve(person){
          return person.firstName;
        }
      },
      lastName:{
        type: GraphQLString,
        resolve(person){
          return person.lastName;
        }
      },
      email:{
        type: GraphQLString,
        resolve(person){
          return person.email;
        }
      },
      posts:{
        type: new GraphQLList(Post),
        resolve(person){
          return person.getPosts();
        }
      }
    };
  }
});

const Post = new GraphQLObjectType({
  name: 'Post',
  description: 'This represents a Post',
  fields: () =>{
    return{
      id:{
        type: GraphQLInt,
        resolve(post){
          return post.id;
        }
      },
      title:{
        type: GraphQLString,
        resolve(post){
          return post.title;
        }
      },
      content:{
        type: GraphQLString,
        resolve(post){
          return post.content;
        }
      },
      person:{
        type: Person,
        resolve(post){
          return post.getPerson();
        }
      }
    };
  }
});

const Query = new GraphQLObjectType({
  name: 'Query',
  description: "This is a root query",
  fields: ()=>{
    return{
      people:{
        type: new GraphQLList(Person),
        args:{
          id:{
            type: GraphQLInt
          },
          email:{
            type: GraphQLString
          }
        },
        resolve(root, args){
          return Db.models.person.findAll({where: args});
        }
      },

      posts: {
        type: new GraphQLList(Post),
        resolve(root, args){
          return Db.models.post.findAll({where: args});
        }
      }

    };
  }
});

const Mutation = new GraphQLObjectType({
  name: 'Mutation',
  description: 'Functions to modify db',
  fields: ()=>{
    return{
        addPerson:{
          type: Person,
          args:{
            firstName:{
              type: new GraphQLNonNull(GraphQLString),
            },
            lastName:{
              type: new GraphQLNonNull(GraphQLString),
            },
            email:{
              type: new GraphQLNonNull(GraphQLString),
            }
          },
          resolve(_,args){
            return Db.models.person.create({
              firstName: args.firstName,
              lastName: args.lastName,
              email: args.email.toLowerCase()
            });
          }
        }
    };
  }
});

const Schema = new GraphQLSchema({
  query: Query,
  mutation: Mutation
});

export default Schema;