Cannot set socket.request to null because the property is read-only

[jonathanperret]

Describe the bug

The Socket.IO documentation suggests setting the request property of the socket object received with the connection event to null. But the types as defined do not allow setting that property from a TypeScript program.

To Reproduce

Note that this is a Socket.IO program, because it is taken from the Socket.IO documentation, but it seems clear that the issue comes from the Socket type declared in Engine.IO, which is why I'm opening this issue here.

Socket.IO server version: 4.7.4

Server

import { Server } from "socket.io";

const io = new Server(8080);

io.on("connection", (socket) => {
    console.log(`connect ${socket.id}`);
    socket.request = null;
});

When compiling with tsc server.ts here is the result:

server.ts:7:12 - error TS2540: Cannot assign to 'request' because it is a read-only property.

7     socket.request = null;
             ~~~~~~~

Found 1 error in server.ts:7

Expected behavior

The request property should not be marked read-only, in order to allow this code to compile.

Workaround

Bypassing the restriction works:

(socket as any).request = null;

[sayhicoelho]

Still can't set it to null on the latest version v4.7.5 using pure Javascript.

Code:

io.on('connection', socket => {
  socket.request = null  
  console.log(socket.request?.session)
})

Output:

Session {
  cookie: {
    path: '/',
    _expires: 2024-08-17T23:50:38.283Z,
    originalMaxAge: 2592000000,
    httpOnly: true,
    domain: '.localhost',
    sameSite: 'lax',
    secure: false
  }
}

[darrachequesne]

@sayhicoelho this should work:

import { type Socket } from "engine.io";

io.engine.on("connection", (rawSocket: Socket) => {
  rawSocket.request = null;
});

In your example:

io.on('connection', socket => {
  socket.request = null;
})

socket.request is a reference to the underlying request object: https://github.com/socketio/socket.io/blob/1f09a3e97950663cd7c62a34c74af60dad8f0346/packages/socket.io/lib/socket.ts#L991-L996