Phone Authentication Issue

[ksinghal]

[READ] Step 1: Are you in the right place?

• For issues related to the code in this repository file a Github issue.
• If the issue pertains to Cloud Firestore, read the instructions in the "Firestore issue"
  template.
• For general technical questions, post a question on StackOverflow
  with the firebase tag.
• For general Firebase discussion, use the firebase-talk
  google group.
• For help troubleshooting your application that does not fall under one
  of the above categories, reach out to the personalized
  Firebase support channel.

[REQUIRED] Step 2: Describe your environment

• Operating System version: Mac OS X Sonoma 14.4.1
• Firebase SDK version: 12.1.0
• Firebase Product: auth
• Node.js version: 20.12.2
• NPM version: 10.5.0

[REQUIRED] Step 3: Describe the problem

We are experiencing an issue where a specific phone number seems to be automatically "cleaned" in Firebase Auth. When we try a auth.createUser call with a specific Netherlands phone number "+310637225615" (attempted across multiple projects), it gets saved as "+31637225615". I am okay with this, but we replicate the phone number in Firestore and this is causing a data discrepancy. At the very least, I think we should be alerted that that this is occurring or that the phone number is invalid?

Steps to reproduce:

What happened? How can we make the problem occur?
This could be a description, log/console output, etc.

Simply initialize Firebase and get a reference to the auth object. Then run the following Javascript/typescript code:

authUser = await auth.createUser({
  uid: "some-user-id",
  phoneNumber: "+310637225615", // exactly this phone number
  displayName: "some display name",
  email: "some email"
});

Relevant Code:

// TODO(you): code here to reproduce the problem

Same code as above:

authUser = await auth.createUser({
  uid: "some-user-id",
  phoneNumber: "+310637225615", // exactly this phone number
  displayName: "some display name",
  email: "some email"
});