Is this the correct way of returning a ES6 promise in firebase cloud functions?

Question

I have a cloud function similar to this:

exports.verifyEmail = functions.https.onCall((data, context) => { // data contains session_id (doc id where otp is stored) and otp
  return new Promise((resolve, reject) => {
    admin.firestore().collection('verification').doc(data.session_id).get().then(doc => {
      if(data.otp === doc.data().otp){
        return resolve()
      } else {
        return reject({message: 'OTP did not match'})
      }
    }).catch(err => {
      return reject({message: err.message})
    })
  })
})

I read this method on a blog somewhere. Now the problem is, when I put wrong OTP on the client side, it shows error as INTERNAL rather than showing the error message OTP did not match . What would be the correct way to send the error message through?

Answer 1

Since the err.message is returning Internal , then you need to change the returned error to what you want:

}).catch(err => {
      return reject({message: "OTP did not match"})
    })