Apollo server setup valid on 10 Jan 2022 (for the course https://www.linkedin.com/learning/learning-graphql-11292553)

index.js

const { createServer } = require('http');
const { execute, subscribe } = require('graphql');
const { SubscriptionServer } = require('subscriptions-transport-ws');
const { makeExecutableSchema } = require('@graphql-tools/schema');
const { ApolloServer, gql } = require('apollo-server-express');
const { MockList } = require('@graphql-tools/mock');
const { ApolloServerPluginLandingPageGraphQLPlayground } = require('apollo-server-core');
const express = require('express');

(async function () {

  const typeDefs = gql`
  scalar Date

  type SkiDay {
    id: ID!
    date: Date!
    mountain: String!
    condition: Conditions
  }

  type Query {
    totalDays: Int!
    allDays: [SkiDay!]!
  }

  enum Conditions {
    POWDER
    HEAVY
    ICE
    THIN
  }

  input AddDayInput {
    date: Date!
    mountain: String!
    condition: Conditions
  }

  type RemoveDayPayload {
    day: SkiDay!
    removed: Boolean
    totalBefore: Int
    totalAfter: Int
  }

  type Mutation {
    addDay(input: AddDayInput!): SkiDay!
    removeDay(id: ID!): RemoveDayPayload!
  }

  type Subscription {
    newDay: SkiDay!
  }
`;

  // const resolvers = {

  // };

  const mocks = {
    Date: () => "12.12.1993",
    Query: () => ({
      allDays: () => new MockList(5),
    }),
  }

  const app = express();
  const httpServer = createServer(app);

  const schema = makeExecutableSchema({
    typeDefs,
    mocks,
    // resolvers,
  });

  const subscriptionServer = SubscriptionServer.create(
    { schema, execute, subscribe },
    { server: httpServer, path: '/graphql' }
  );

  const server = new ApolloServer({
    schema,
    plugins: [
      {
        async serverWillStart() {
          return {
            async drainServer() {
              subscriptionServer.close();
            }
          };
        }
      },
      ApolloServerPluginLandingPageGraphQLPlayground(),
    ],
  });
  await server.start();
  server.applyMiddleware({ app });

  const PORT = 4000;
  httpServer.listen(PORT, () =>
    console.log(`Server is now running on http://localhost:${PORT}/graphql`)
  );
})();