Passport.js authenticate issue with two simultaneous sessions : "Cannot set headers after they are sent to the client"

[xmonvoisin]

Hi,

I have issue with this code when testing using 2 simultaneous users (Playwright tests, using 2 workers) :

passport.authenticate(strategy, {}, { failureRedirect: /login, state: redirect_url }), (err, user, info) => { if (err || !user) { return next(err || info); } req.logIn(user, err => { if (err) { return next(err); } if (loginpopup) { ... } else { return res.redirect('/'); } }); })(req, res, next);
I am receiving this error:

Error: Cannot set headers after they are sent to the client ...

It seems to come from the "res.redirect('/')"
From various posts on stackoverflow, I kind of understand that the issue come from the fact that I do a redirect inside the "authenticate" callback and that redirect interfer with passport's redirect. But I don't know how to solve this.

Could you please help me understand and fix this issue ?
Thanks you

[fergus99]

I had a very similar issue. I fixed it by replacing "passport.authenticate(strategy..." with "passport.authenticate('strategyName'...".
I think this is down to a bug in Passport whereby the authenticate function creates the strategy using Object.create() on the prototype only in the case of the strategy being passed as a string. Alternatively you could use passport.authenticate(Object.create(strategyName)...".

[BeataKr]

Thank you. Seems to be a good fix.