res.redirect happening before req.flash

[franckl]

Hi Jerome,

It seems connect-mongo is causing the issue referenced below :
jaredhanson/connect-flash#23 (comment)

What do you think ?

[behcet]

It's a race condition. User gets redirected to new page before session gets saved on database.

Try executing a req.session.save(callback) after calling req.flash and wait for save callback to redirect to user.

[behcet]

@franckl Any updates ?

[jdesboeufs]

Ok it's not related to connect-mongo.
connect-flash should be fixed to ensure session has been saved (whatever the session store used).

[malcolmocean]

For people who come across this in future searching...

I was halfway through rolling my own new version of req.flash, when I was looking through the docs of express-session and came across this gem:

Note Since version 1.5.0, the cookie-parser middleware no longer needs to be used for this module to work. This module now directly reads and writes cookies on req/res. Using cookie-parser may result in issues if the secret is not the same between this module and cookie-parser.

And lo, I had these lines:

app.use(require('cookie-parser')())
const session = require('express-session')
const MongoStore = require('connect-mongo')(session)
app.use(session({
  secret: process.env.SESSION_STORE_SECRET,
  store: new MongoStore({mongooseConnection: mongoose.connection}),
  maxAge: 10*365*24*60*60*1000, // set to 10 years
  resave: false,
  saveUninitialized: false
}))

Once I changed the cookie-parser line to:

app.use(require('cookie-parser')(process.env.SESSION_STORE_SECRET))`

it worked exactly as expected!

(For some people, the answer will be to remove cookie-parser altogether.)