The second factor "uid" must be a valid non-empty string

[flyingluscas]

Describe your environment

• Operating System version: Arch Linux
• Firebase SDK version: 9.5.0
• Firebase Product: Auth
• Node.js version: 14.15
• NPM version: 6.14.11

Describe the problem

The admin.auth().updateUser function does not allow me to add a second factor to an existing user, always triggering the error The second factor "uid" must be a valid non-empty string., the function expects a valid uid but according to the docs it should not, if no uid is informed it should auto generate one. Can anyone help me understand if this is a bug in the lib or am I doing something wrong?

Steps to reproduce:

1. Create a user without any secondary factors.
2. Try to add a new secondary factor using the .updateUser function.

Relevant Code:

admin.auth().updateUser('123456789', {
 phoneNumber: '+16505550003',
 emailVerified: true,
 multiFactor: {
 enrolledFactors: [
 {
 phoneNumber: '+16505550003',
 displayName: 'Bender Bending Rodríguez',
 factorId: 'phone',
 },
 ],
 },
})

[hiranya911]

Current implementation treats UID to be required for update operations:

firebase-admin-node/src/auth/auth-api-request.ts

Line 278 in e7155ea

const uidRequired = writeOperationType !== WriteOperationType.Create;

@bojeil-google is that a bug?

[bojeil-google]

I think it is a bug in our code. I tried to send the request directly to confirm the backend API does not require the uid and it seems to work without it. It will provision a new uid on its own. We should remove that check uidRequired. I am also double checking this is the intended behavior with some backend folks.

[bojeil-google]

The tests seem to be currently broken (only partially running). If you can help fix that, I am happy to review.

[silviokucz]

As of 1/31/2023 I am still experiencing this issue.
My environment:

Operating System version: Ubuntu Linux
Firebase SDK version:11.19.0
Firebase Product: Auth
Node.js version: v14.21.2
NPM version: 6.14.17

My exact call:
admin.auth().updateUser('yBap141NgrR6o4cvaVOAEQVdaGCl', {
multiFactor: {
enrolledFactors: [
{
phoneNumber: '+14255555504',
displayName: 'MFA',
factorId: 'phone',
},
],
},
})

Seems to work when the user is already multifactor but fails otherwise.