Password policy violation is reported as auth/internal-error instead of a specific error code #3265

[REQUIRED] Step 2: Describe your environment

• Operating System version: macOS 15.7.7 (local), Cloud Functions Node.js 20 runtime (production)
• Firebase SDK version: firebase-admin 13.8.0 (also reproduced on 14.5.0)
• Firebase Product: auth
• Node.js version: 20.19.2
• NPM version: 10.8.2

[REQUIRED] Step 3: Describe the problem

Steps to reproduce:

With a password policy in Require (ENFORCE) mode, auth().createUser() or updateUser() with a non-compliant password rejects with auth/internal-error, not a specific error code.

The server returns PASSWORD_DOES_NOT_MEET_REQUIREMENTS, but that code is missing from AUTH_SERVER_TO_CLIENT_CODE in src/auth/error.ts. FirebaseAuthError.fromServerError therefore falls back to INTERNAL_ERROR. Callers can't tell this user-input error from a real internal error without parsing the message. The client SDK already uses auth/password-does-not-meet-requirements for the same case.

1. Enable a password policy in Require mode, e.g. minimum length 10.
2. Call createUser with a password that doesn't meet it.

Actual: code is auth/internal-error, and the server code only appears in the message:

Missing password requirements: [Password must contain at least 10 characters, Password must contain a lower case character, Password must contain an upper case character] Raw server response: "{"error":{"code":400,"message":"PASSWORD_DOES_NOT_MEET_REQUIREMENTS : Missing password requirements: [...]","errors":[...]}}"

Expected: a specific code, e.g. auth/password-does-not-meet-requirements to match the client SDK, keeping the missing-requirements message.

Suggested fix: add PASSWORD_DOES_NOT_MEET_REQUIREMENTS to AUTH_SERVER_TO_CLIENT_CODE, with a matching AuthErrorCode entry, in src/auth/error.ts.

Relevant Code:

const { getAuth, FirebaseAuthError } = require("firebase-admin/auth");

// Against a project with a password policy in Require mode:
try {
  await getAuth().createUser({ email: "user@example.com", password: "weakpass" });
} catch (err) {
  console.log(err.code); // "auth/internal-error"
}

// Same mapping, without a project:
const err = FirebaseAuthError.fromServerError(
  "PASSWORD_DOES_NOT_MEET_REQUIREMENTS : Missing password requirements: [Password must contain at least 10 characters]"
);
console.log(err.code); // "auth/internal-error", expected "auth/password-does-not-meet-requirements"