Socket.io with express, specific room - node.js

Question

I want to send event to only an specific client when an express rute is triggered.
I keep online users in io.onlineUsers:
socket.on("log-in", (userWithRoles) => {
const userSocket = {
id: userWithRoles.id,
roles: userWithRoles.roles,
socketId: socket.id,
};
if (io.onlineUsers === undefined) {
io.onlineUsers = [
{ ...userSocket, socketIds: [userSocket.socketId], room: socket.id },
];
} else {
if (
io.onlineUsers.map((uSocket) => uSocket.id).includes(userSocket.id)
) {
const existingUserSocket = io.onlineUsers.find(
(us) => us.id === userSocket.id
);
existingUserSocket.socketIds.push(userSocket.socketId);
socket.join(existingUserSocket.room);
return;
}
io.onlineUsers.push({
...userSocket,
socketIds: [userSocket.socketId],
room: socket.id,
});
}
});
I attach io via:
httpsServer.listen(process.env.PORT || 5000, () => {
const io = createIo(httpsServer);
app.io = io;
console.log(
`Server running on port ${
process.env.PORT || 5000
}. Go to https://localhost:5000/.`
);
});
I am looking for room/socketId in a router via:
const getAllCookRoles = async (req, res) => {
const cookRoles = await CookRoleUser.find()
.populate({ path: "user", select: "username name" })
.populate({ path: "cooks" });
console.log(req.app.io.onlineUsers);
const cookRoom = req.app.io.onlineUsers?.find((ou) =>
ou.roles.map((ouRole) => ouRole.name).includes(COOK)
)?.room;
console.log(cookRoom);
if (cookRoom) {
console.log(cookRoom);
req.app.io.sockets.to(cookRoom).emit("page-visit");
}
res.json(cookRoles);
};
And the client listener is:
useEffect(() => {
const socket = io("https://localhost:5000");
// receive a message from the server
socket.on("new-order", (socketData) => {
console.log("neworder");
console.log(socketData);
});
socket.on("page-visit", () => {
console.log("page-visit");
})
}, []);
When i do req.io.emit("page-visit") everyithing works like a charm.
Contrarly, besides fiding and logging the cook room, when i do req.app.io.sockets.to(cookRoom).emit("page-visit"); nothing happens. With .sockets part and w/out.
How could I send event to specific room, not everyone, from express route?