Quickly scaffold and express server with graphql

graphql-express.js

const express = require('express');
const bodyParser = require('body-parser');
const { graphqlHTTP } = require('express-graphql');

//  build schema allows you to build your schema as a string literal, processed through
//  then build schema converts it into a js object
//  then use it in the "schema" property in the express graphql middleware
//  alternatively you can create these schemas in object form using graphql's GraphQLObjectType, and types like GraphQLString,
//  GraphQL object types act more like components with resolvers included

// learn more here: https://graphql.org/graphql-js/basic-types/#:~:text=The%20GraphQL%20schema%20language%20supports,any%20of%20the%20scalar%20types.

const { buildSchema } = require('graphql');

const app = express();

const events = [];

app.use(bodyParser.json());

//  only one endpoint for requests to go to
//  graphqlHttp middleware goes here
//  allows graphql to talk with express
//  schema is the shape of your data
//  buildSchema expects a `schema` type with `query` and `mutation`
//  rootValue — a resolver for your schema
//  rootValue resolvers must match the name of the queries
//  with template literals it has some overlap with ts syntax
//  input type allows you to define argument inputs
app.use(
  '/graphql',
  graphqlHTTP({
    schema: buildSchema(`
        type Event {
            _id: ID
            title: String!
            description: String!
            price: Float!
            date: String!
        }

        input EventInput {
            title: String!
            description: String!
            price: Float!
            date: String!
        }

        type RootQuery {
            events: [Event!]!       
        }

        type RootMutation {
            createEvent(eventInput: EventInput): Event
        }

        schema {
            query: RootQuery
            mutation: RootMutation
        }
    `),
    rootValue: {
      events: () => {
        return events;
      },
      //   you get an args object for each incoming request
      createEvent: (args) => {
        //    have to destructure the event input object off of the arguments
        var { eventInput } = args;
        const event = {
          _id: Math.random().toString(),
          title: eventInput.title,
          description: eventInput.title,
          price: +eventInput.price,
          date: new Date().toISOString(),
        };
        events.push(event);
        console.log(args);
        return event;
      },
    },
    graphiql: true,
  })
);

app.listen(3000, () => {
  console.log('listening on port 3000');
});