Using middlewares on application level

[serp-ya]

Hi mates!

I try to create common middleware for my websocket application, but I can't to understand socket.io middlewares philosophy when I use namespaces.

What I doing:

// server side
import { Server } from 'socket.io';

const websocket = new Server();

websocket.use((socket, next) => {
    console.log('common');
    next();
});

websocket.of('/admin').use((socket, next) => {
        console.log('admin');
        next();
    });

// client side
const socket = io.connect('/admin');

Expected behavior:
Both middlewares was executed because I use middleware on Namespace instance who was create from Server instance.

Real behavior:
Only Namespace's middleware was execute...

I have same issue when I try to create dynamicly namespaces with regexp:

// server side
import { Server } from 'socket.io';

const websocket = new Server();

websocket.use((socket, next) => {
    console.log('common');
    next();
});

websocket.of(/^\/\w+$/).use((socket, next) => {
        console.log('regexp');
        next();
    });

websocket.of('/admin').use((socket, next) => {
        console.log('admin');
        next();
    });

// client side
const socket = io.connect('/admin');

Expected behavior:
Middleware on regexp namespace was executed because this is above /admin namespace

Real behavior:
Only /admin Namespace middleware was execute...

How can I to set one middleware on all namespaces?

NOTE: in this case I was use "standalone" initialization type, but I reproduced same behavior with different initialization types from official site

[darrachequesne]

This was indeed the behavior in Socket.IO v2: even when using a namespace (io.connect('/admin')), you were implicitly connected to the main namespace (/), which is quite surprising.

This should not happen anymore with Socket.IO v3.

See also: https://socket.io/docs/v3/migrating-from-2-x-to-3-0/#No-more-implicit-connection-to-the-default-namespace

Regarding the dynamic namespace feature, the middleware registered here:

websocket.of(/^\/\w+$/).use((socket, next) => {
  console.log('regexp');
  next();
});

is indeed registered on each child namespace. I will update the documentation about this.

[serp-ya]

Damien. hi!

Thank you for quick answer!

About my last example with dynamic namespaces - my code have next behavior:

// server side
import { Server } from 'socket.io';

const websocket = new Server();

websocket.of(/^\/\w+$/).use((socket, next) => {
  console.log('regexp');
  next();
});

 // "admin" with single "n"
websocket.of('/admin').use((socket, next) => {
        console.log('admin');
        next();
    });

// client side
const socket = io.connect('/adminn'); // "admin" with double "n"

// Output will be 'regexp'

But if I connecting to "admin" with single "n" behavior was change

// server side
import { Server } from 'socket.io';

const websocket = new Server();

websocket.of(/^\/\w+$/).use((socket, next) => {
  console.log('regexp');
  next();
});

websocket.of('/admin').use((socket, next) => {
        console.log('admin');
        next();
    });

// client side
const socket = io.connect('/admin');

// Output will be 'admin'

I think it looks strange because in this case I expect registration of my middleware with regexp on each namespace, but works only one...