I\'m trying to do this since a lot of days but all my tests fails...
Users on my platform connect them by using passportjs strategies (paypal, facebook, google...).<
This is still one of the top results for 'update session passport js', so I thought I'd add what worked for me (the provided answers didn't work for me):
req.session.passport.user.updatedfield= 'updatedvalue'
req.session.save(function(err) {console.log(err);}
Without req.session.save() the session data would not update for me.
Hope this helps someone.