Setting up Socket.IO

To set up the Socket.IO server, we are going to base our code on what we had in Chapter 6, Adding Authentication and Roles with JWT, as it already includes some boilerplate for a backend and frontend with JWT authentication. Later in this chapter, in the Adding authentication by integrating JWT with Socket.IO section, we are going to make use of JWT to add authentication to Socket.IO:

1. Copy the existing ch6 folder to a new ch13 folder, as follows:

   $ cp -R ch6 ch13

2. Open the ch13 folder in VS Code.
3. Now, we can start setting up Socket.IO. First, install the socket.io package in the backend folder by running the following commands:

   $ cd backend/
   $ npm install socket.io@4.7.2

4. Edit backend/.env and change DATABASE_URL so that it points to a new chat database:

   DATABASE_URL=mongodb://localhost:27017/chat

5. Edit backend/src/app.js and import the createServer function from node:http and the Server function from socket.io:

   import { createServer } from &apos...