ERR_HTTP_HEADERS_SENT: Cannot set headers after they are sent to the client

Question

I\'m facing this weird issue in NodeJS when using with Passport.js, Express and Mongoose. Basically, I get an error saying \"Cannot set headers after they are sent to the cl

Answer 1

I got the same error using express and mongoose with HBS template engine. I went to Expressjs and read the docs for res.render, and it says // if a callback is specified, the rendered HTML string has to be sent explicitly. So I wasnt originally sending my html explicitly in the callback,. This is only for a contact form btw, not login info, albeit GET

//Original
let { username, email } = req.query;  //My get query data easier to read

res.status(200).render('index', { username, email });

//Solution without error. Second param sending data to views, Third param callback

res.status(200).render('index', { username, email }, (err, html)=>{
      res.send(html);
 });