Expo: Is this possible todo firebase phone auth in expo without detach ?

[arunxampr]

Please help...
getting issues because of re-captcha required to ' firebase.auth().signInWithPhoneNumber'

[terribleben]

Hi, I think you need to detach for that. We have feature requests related to this here and here. Please upvote them!

[artokun]

Original Thread: https://forums.expo.io/t/firebase-phone-auth/4696/17

This shows the steps necessary to get phone auth working with firebase functions along with twilio for SMS. It's not a bad workaround, fairly easy to implement WITHOUT detaching.

Just need to sign up for twilio, npm i -g firebase-tools, and run firebase init on your project root.

Updated to use firestore instead of the realtime database.

```js
// /functions/index.js

const functions = require('firebase-functions');
const admin = require('firebase-admin');

/*
set environment variables via terminal
$ firebase functions:config:set twilio.account= twilio.token= twilio.from=
*/
const config = functions.config();
const twilio = require('twilio')(config.twilio.account, config.twilio.token);

/*
Now you need to download a private cert (service-account.json)
https://firebase.google.com/docs/admin/setup#add_firebase_to_your_app
and add add it to your /functions directory (don't forget to .gitignore it)
*/
const serviceAccount = require('./service-account.json');
admin.initializeApp({
credential: admin.credential.cert(serviceAccount),
databaseURL: 'https://.firebaseio.com',
});

// Looks for user by phone number. If found (new log in), sends
// verfication. If not found (new sign up), creates new user and
// sends verification
exports.logInWithPhoneNumber = functions.https.onRequest((req, res) => {
const { phone } = req.body;
admin
.auth()
.getUserByPhoneNumber(phone)
.then(userRecord => sendSMSVerification(res, userRecord.uid, phone))
.catch(error => {
switch (error.code) {
case 'auth/user-not-found':
return createUser();
default:
return sendError(error);
}
});

const createUser = () => {
admin
.auth()
.createUser({
phoneNumber: phone,
})
.then(({ uid }) => sendSMSVerification(res, uid, phone))
.catch(sendError);
};

const sendError = error => res.status(422).send(error);

const sendSMSVerification = (res, uid, phone) => {
const code = Math.floor(Math.random() * 899999 + 100000);
const expiration = Date.now() + 2 * 60000; // Expires in 2 minutes
const verification = { code, expiration, valid: true };
const setUser = message => {
admin
.firestore()
.collection('users')
.doc(uid)
.set({ verification })
.then(() => res.send({ success: true }))
.catch(sendError);
};
twilio.messages
.create({
body: Your family code is ${code},
to: phone,
from: config.twilio.from,
})
.then(setUser)
.catch(sendError);
};
});

exports.verifyToken = functions.https.onRequest((req, res) => {
// Validate code and expiration time, ensuring that code hasn't been used before.
// If matches, create custom auth token and then invalidate code
const { code, phone } = req.body;
const sendError = error => res.status(422).send({ error: error.message });

admin
.auth()
.getUserByPhoneNumber(phone)
.then(userRecord => {
return admin
.firestore()
.collection('users')
.doc(userRecord.uid)
.get();
})
.then(doc => {
if (!doc.exists) {
return Promise.reject(new Error('custom/uid-not-found'));
}

  const timeNow = Date.now();
  const { verification } = doc.data();
  let error = null;

  if (verification.code !== parseInt(code, 10)) {
    error = 'custom/code-does-not-match';
  } else if (!verification.valid) {
    error = 'custom/code-already-used';
  } else if (timeNow > verification.expiration) {
    error = 'custom/code-expired';
  }

  if (error) {
    return Promise.reject(new Error(error));
  }

  doc.ref.update({ 'verification.valid': false });
  return Promise.resolve(doc.id);
})
.then(uid => admin.auth().createCustomToken(uid))
.then(token => res.send({ token }))
.catch(sendError);

});

[evilandfox]

Hope this helps: https://stackoverflow.com/a/52350212/5245349