Feathers: login event emit twice for same user using socket.io

This is a confirmed bug, originally reported in https://github.com/feathersjs/authentication/issues/673. Keeping this one open to track things here.

@daffl ,

I noticed that this happens because of socket transport upgrade from polling to websocket that's when you will see two login events.

another thing i noticed that if i run feathers server and client locally than i don't see two login event i.e in same local network; if i put client and server apart via internet than only i see two login events that's may be because of network latency.

I figured two possible workaround for this to prevent two login events.

1. In feathers client if you configure socket with upgrade false than you will not see two login events
2. Or if you put configure transport in this order than also you will not see two login events transports: [ 'websocket','polling']

I've right now used transport in revers order i.e. fallback approach; so i'm not getting two login events.
I know this is temporary fix ideally socket should prevent that OR it should fire two logout in conjunction to that

Could this be related to why I keep getting an error of app.emit is not a function when users attempt to login?

Thanks for digging into this @vinaykharecha. I'll verify that this is no longer happening for Authentication v3 (https://github.com/feathersjs/feathers/issues/1045)

@daffl ,

I noticed that this happens because of socket transport upgrade from polling to websocket that's when you will see two login events.

another thing i noticed that if i run feathers server and client locally than i don't see two login event i.e in same local network; if i put client and server apart via internet than only i see two login events that's may be because of network latency.

I figured two possible workaround for this to prevent two login events.

1. In feathers client if you configure socket with upgrade false than you will not see two login events
2. Or if you put configure transport in this order than also you will not see two login events transports: [ 'websocket','polling']

I've right now used transport in revers order i.e. fallback approach; so i'm not getting two login events.
I know this is temporary fix ideally socket should prevent that OR it should fire two logout in conjunction to that

@vinaykharecha where you changed order of transports? Thanks!

@matiaslopezd ,

Order of transports needs to be changed on client side not server side.
On client side code where you are configuring socket io at that time you need to pass option.
Following is example snippet; in that replace "https://feathers.domain.com" with your feathers server url

const feathers = require('@feathersjs/feathers');
const socketio = require('@feathersjs/socketio-client');
const io = require('socket.io-client');
const app = feathers();
const socket = io("https://feathers.domain.com", {
    transports: ['websocket','polling'],
    forceNew: true
});

app.configure(socketio(socket));

@vinaykharecha thanks you! :smile:

Closing since this should no longer be happening in Feathers v4 authentication. See the Migration guide for more information on how to upgrade.

@daffl new version? :scream:

I have this problem again and I use v4.
my config:
"@feathersjs/authentication-client": "^4.5.1",
"@feathersjs/feathers": "^4.5.1",
"@feathersjs/socketio-client": "^4.3.11",

Results of connection:
Authentication successful for: xyz // console.log from authenticate
New connection request. event is: login // from handleConnection
Adding authentication information to connection: xyz // from handleConnection
New connection request. event is: login
Adding authentication information to connection: xyz
Anonymous connection request // from channels, app.on('connection',.... but the connection is known
User xyz has joined 6 channels // from channels, app.on('login',.....
User xyz @vhci.ro has joined 6 channels