How to use Node.js EventEmmiter

events.js

// https://nodejs.org/api/events.html
const EventEmmiter = require("events");
const eventEmmiter = new EventEmmiter();

const cooking = async ({ name }) => ({ name });
const driveTo = async () => true;
const leave = async () => ({ delivered: true });

async function cook({ pizzaOrder, user }) {
  console.log(`Cooking a ${pizzaOrder.name}`);

  return cooking(pizzaOrder).then((pizza) => {
    console.log(`The ${pizza.name} is ready! In time to deliver!`);

    eventEmmiter.emit("deliver", { address: user.address, pizza });
  });
}

async function deliver({ pizza, address }) {
  console.log(`Driving to ${address}`);

  return driveTo(address).then(() => {
    console.log(`Delivering the ${pizza.name} at ${address}`);

    return leave(pizza);
  });
}

eventEmmiter
  .on("order", (details) => {
    console.log("A new pizza order arrived");

    cook(details);
  })
  .on("deliver", async ({ address, pizza }) => {
    console.log("Calling delivery man!");

    deliver({ pizza, address }).then(({ delivered }) => {
      if (delivered) {
        console.log("Close order");
      } else {
        console.log("Ops! The pizza was not delivered");
      }
    });
  });

eventEmmiter.emit("order", {
  pizzaOrder: {
    quantity: 1,
    name: "Master Pizza",
    description: "Provolone, Green Olives, Green Peppers",
  },
  user: {
    address: "682 Cheyenne Stream",
  },
});

// A new pizza order arrived
// Cooking a Master Pizza
// The Master Pizza is ready! In time to deliver!
// Calling delivery man!
// Driving to 682 Cheyenne Stream
// Delivering the Master Pizza at 682 Cheyenne Stream
// Close order