batch_delete.js

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

admin.initializeApp();

// Lookup user accounts by uid, email, phone number of IdP-assigned uid.
// List up to 100 identifiers to lookup.
const uids = [
  {uid: 'sample-uid-1'},
  {uid: 'sample-uid-2'},
  {email: '[email protected]'},
  {phoneNumber: '+1234567890'},
  {providerId: 'google.com', providerUid: '[email protected]'},
];

const markedForDelete = [];

// Retrieve a batch of user accounts.
admin.auth().getUsers(uids)
  .then((result) => {
    // Mark disabled accounts for deletion.
    result.users.forEach((user) => {
      if (user.disabled) {
        markedForDelete.push(user.uid);
      }
    });

    result.notFound.forEach((uid) => {
      console.log(`No user found for identifier: ${JSON.stringify(uid)}`)
    });
  })
  .then(() => {
    // Delete all marked user accounts in a single API call.
    return admin.auth().deleteUsers(markedForDelete);
  });