What is expected if CORS object is empty while initialisation?

[arpitkapoor97]

Discussed in #5272

^{Originally posted by arpitkapoor97 January 1, 2025}
Consider below scenarios, when I am trying to connect a client from a different PORT/URL.

`
const app = express();
const server = createServer(app);

const io = new Server(server);
// This gives CORS error
const io = new Server(server, {});
// This also gives CORS error

const io = new Server(server, {
cors: {}
});`

// This gives no CORS error. WHY?

PS: I am experimenting this on code spaces so it might behave differently.