Export/import firebase users from one account to another

copyFirebaseUsers.js

const admin = require("firebase-admin");

const serviceAccountOld = require("./../../.serviceAccountKey.json");
const serviceAccountNew = require("./../../.serviceAccountKey-new.json");
const appOld = admin.initializeApp({
    credential: admin.credential.cert(serviceAccountOld),
    databaseURL: "https://old.firebaseio.com",
}, "old");
const appNew = admin.initializeApp({
    credential: admin.credential.cert(serviceAccountNew),
    databaseURL: "https://new.firebaseio.com",
}, "new");
appOld.auth().listUsers().then(data => {
    console.log(data.users.length, "users")
    const converted = data.users.map(user => ({
        ...user,
          passwordHash: Buffer.from(user.passwordHash),
          passwordSalt: Buffer.from(user.passwordSalt),
    }));
    return appNew.auth().importUsers(converted, {
        hash: {
          algorithm: 'SHA1',
          rounds: 1
        }
      })
}).then((res) => {
    console.log("imported")
    console.log(res)
    process.exit(0)
}).catch(e => {
    console.log(e);
})