server.js

const { ApolloServer, gql } = require("apollo-server");
const typeDefs = gql`
  type Speaker {
    id: ID!
    first: String
    last: String
    favorite: Boolean
  }

  type SpeakerResults {
    datalist: [Speaker]
  }
  type Query {
    speakers(limit: Int): SpeakerResults
  }
`;
const resolvers = {
  Query: {
    speakers: () => {
      const speakers = [
        { id: 101, first: "david", last: "jones", favorite: true },
        { id: 102, first: "david", last: "jones", favorite: false },
        { id: 103, first: "david", last: "jones", favorite: true },
      ];
      return {
        datalist: speakers,
      };
    },
  },
  SpeakerResults: {
    datalist: (parent) => {
      return parent.datalist;
    }

  },
  Speaker: {
    first: (parent, args, context, info) => {
      return `${parent.first.toUpperCase()}`;
    },
    last: (parent) => {
      return parent.last;
    },
    id: (parent) => {
      return parent.id;
    },
    favorite: (parent) => {
      return parent.favorite;
    }
  },
};

async function apolloServer() {
  const server = new ApolloServer({
    typeDefs,
    resolvers,
  });
  server.listen(4000, () => {
    console.log(`ApolloServer GraphQL Simple running at port ${PORT}`);
  });
}

apolloServer();