ExpressJS POST Route unhandled promise rejection

Question

I have an Express app which has the following POST route:

//Main API route
  app.post("/api/v1/forms/:formId", async (req, res) => {
    //TODO: Create Mailer and email templates before finalising route.
    const { _name, _email, _message } = req.body;

    let newForm;

    Form.findById(req.params.formId, err => {
      if (err) {
        res.send(err);
      } else {
        const newForm = new Form({
          name,
          email,
          message,
          recipient: form.recipient
        });
        res.send(req.body);
      }
    });
    const mailer = new Mailer(newForm, contactFormTemplate(newForm));
    try {
      await mailer.send();
    } catch (err) {
      res.status(422).send(err);
    }
  });

When I make a POST request to this route, the res.send(req.body); returns an empty object and I get the error "UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 1): ReferenceError: newForm is not defined"

I can't see why it is saying the variable newForm is not defined. I have found that the newForm is undefined in the Mailer line:

const mailer = new Mailer(newForm, contactFormTemplate(newForm)); I can't see why this line is not being passed the newForm variable as it is in the same app.post function scope.

`let newForm;` and then `const newForm = new Form({` is probably causing issues. — dave, Apr 20 '18 at 20:33
Dave is correct. Then, when that syntax error fires, the `asyc` `app.post()` callback is rejected, which you do not handle. Hence the error. — Randy Casburn, Apr 20 '18 at 20:35
You should always wrap your async function calls in try/catch blocks: `try { app.post(...)} catch(){}` — Randy Casburn, Apr 20 '18 at 20:36
I have removed the `let newForm;` and wrapped the route in a try/catch but this makes no difference — Luke, Apr 20 '18 at 20:42

ExpressJS POST Route unhandled promise rejection

0 Answers0