GraphQL Wishlist Example With User System(https://launchpad.graphql.com/3kvzv77m1v)

index.js

// Welcome to Launchpad!
// Log in to edit and save pads, run queries in GraphiQL on the right.
// Click "Download" above to get a zip with a standalone Node.js server.
// See docs and examples at https://github.com/apollographql/awesome-launchpad

// graphql-tools combines a schema string with resolvers.
import { makeExecutableSchema } from 'graphql-tools'

// Construct a schema, using GraphQL schema language
const typeDefs = `
  type Mutation {
    addWhatIWantToList(name: String!, description: String, nHowMany: Int!, listId: Int!): WishList!
		createNewList(title: String!, description: String): [WishList!]!
  }

  type WhatIWant {
    id: Int!
    name: String!
    description: String
    nHowManyWant: Int!
  }

  type WishList {
    id: Int!
    # user: User!
    title: String!
    description: String
    things: [WhatIWant]!
  }

  # type User {
  #   id: Int!
  #   name: String!
  #   wishLists: [WishList]!
  # }

  type Query {
		# All wishlists
		myWishLists: [WishList!]!
    whatIWant(id: Int!): WhatIWant!
		wishList(id: Int!): WishList!
    wishLists(id: Int!): [WishList]!
    # wishListsByUserId(id :ID!): [WishList]!
		# me: User!
		# user(id: Int!): User!
  }
`

// 余裕があればこういうのも使ってみたい https://developers.google.com/books/
// i.e.) https://www.googleapis.com/books/v1/volumes?q=isbn:4774176982
const BooksIWant = [
  {
    id: 1,
    name: 'Haskellによる並列・並行プログラミング',
    description: '難しそう',
    nHowManyWant: 1
  },
  {
    id: 2,
    name: 'Coq/SSReflect/MathCompによる定理証明:フリーソフトではじめる数学の形式化',
    description: '最近出たっぽい',
    nHowManyWant: 1
  }
]

const FoodsIWannaEat = [
  {
    id: 3,
    name: 'うな重',
    description: '食べて応援',
    nHowManyWant: 10
  },
  {
    id: 4,
    name: 'エビフライ',
    description: '普通に好き',
    nHowManyWant: 8000
  }
]

const whatIWants = [...BooksIWant, ...FoodsIWannaEat]

// const myId = 0;

const wishLists = [
  {
    id: 1,
    // userId: myId,
    title: 'ほしい本',
    description: 'ほしいけれど高くて買えていない本のリスト',
    things: BooksIWant
  },
  {
    id: 2,
    // userId: myId,
    title: '食べたいもの',
    description: '高級食材',
    things: FoodsIWannaEat
  }
]

// User
// const me = {
//   id: myId,
//   name: 'e_ntyo'
// };

// const user1 = {
//   id: 1,
//   name: 'potato4d'
// };

// const user2 = {
//   id: 2,
//   name: 'masaakikunsan'
// }

// const users = [me, user1, user2]

// Provide resolver functions for your schema fields
const resolvers = {
  Query: {
    // me: () => me,
    myWishLists: () => wishLists,
    whatIWant: (_, { id }) => whatIWants.find(v => id === v.id),
    wishList: (_, { id }) => wishLists.find(v => id === v.id),
    // user: (_, { id }) => users.find(v => id === v.id)
  },
  Mutation: {
    addWhatIWantToList: (_, { nHowMany, name, description, listId }) => {
      const wl = wishLists.find(v => v.id === listId)
      const { things } = wl
      const { id } = things[things.length - 1]
      things.push({ id: id + 1, nHowMany, name, description })
      const newList = {
        ...wl,
        things
      }
      wishLists.filter(v => v.id !== listId).push(newList)
      return newList
    },
    createNewList: (_, {title, description}) => {
      const id = wishLists[wishLists.length - 1].id + 1
      const newList = {
        id,
        title,
        description
      }
      wishLists.push(newList)
      return wishLists
    }
  }
  // User: {
  //   wishLists: user => wishLists.filter(v => v.userId === user.id)
  // },
  // WishList: {
  //   user: wishList => users.find(v => v.id === wishList.userId)
  // }
}

// Required: Export the GraphQL.js schema object as "schema"
export const schema = makeExecutableSchema({
  typeDefs,
  resolvers,
})

// Optional: Export a function to get context from the request. It accepts two
// parameters - headers (lowercased http headers) and secrets (secrets defined
// in secrets section). It must return an object (or a promise resolving to it).
export function context(headers, secrets) {
  return {
    headers,
    secrets,
  }
}