How do I return a list of users if I use the Firebase simple username & password authentication

Question

Not sure if I am doing something wrong but using this api https://www.firebase.com/docs/security/simple-login-email-password.html I can successfully create a user - accordin

Answer 1

It's possible to use cloud function to fetch users list (view docs at firebase). Note, in the following example custom claims feature is used to check if user has enough privileges.

// USERS: return full users list for admin
// >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
import * as admin from 'firebase-admin'
import * as functions from 'firebase-functions'

export const listUsers = functions.https.onCall((data, context) => {
  // check if user is admin (true "admin" custom claim), return error if not
  const isAdmin = context.auth.token.admin === true
  if (!isAdmin) {
    return { error: `Unauthorized.` }
  }

  return admin
    .auth()
    .listUsers()
    .then((listUsersResult) => {
      // go through users array, and deconstruct user objects down to required fields
      const result = listUsersResult.users.map((user) => {
        const { uid, email, photoURL, displayName, disabled } = user
        return { uid, email, photoURL, displayName, disabled }
      })

      return { result }
    })
    .catch((error) => {
      return { error: 'Error listing users' }
    })
})