Deletes all records from a Firestore collection that match some criteria -- command-line JavaScript/node

cleanup_firestore.js

/**
 * cleanup_firestore.js
 *
 * This code is a "node script" used to delete all documents from a Firestore
 * collection that are older than a given date.  This script can run against
 * "the cloud" or the emulator.
 *
 * The jump point for the script is this line in main():
 *
 *    await deleteDocs('orders', 'closedDate', '<', new Date('2021/08/31'))
 *
 * where `orders` is the collection and `closedDate` is a field in each document.
 *
 * The script is a "client app", so it logs in with Firebase Auth using email/password from the variable USER1.
 * This USER1 user (the.admin.guy@test.com) must exist in your Firebase project and have write access
 * to the collection you are deleting from.  You can create that user account via
 * Firebase Console >> Authentication.
 *
 * This script is assumed to live in an existing Javascript project that has its own package.json.
 * I store this script in <PROJECT_ROOT>/tools/cleanup/.
 *
 * To use:
 *  1. Import the 'firebase' and 'esm' NPM modules to your project (Run the command: `npm install firebase esm`)
 *  2. Edit the data for USER1 and FIREBASE_CONFIG, then adjust parameters in `main` for the call to `deleteDocs()`.
 *
 * NOTE: this code works with the Firebase Web SDK v9 API.  Earlier revisions used the v8 API.
 *
 * To run: node cleanup_firestore.js
 *
 *   Alternatively, you can create a "script" in package.json:
 *     "scripts": {
 *          ...
 *        "cleanup": "node tools/cleanup/cleanup_firestore.js"
 *     }
 *
 *   and then run the script with:  npm run cleanup
 */

import {initializeApp} from 'firebase/app';
import {
  addDoc,
  collection,
  connectFirestoreEmulator,
  getFirestore,
  writeBatch
} from 'firebase/firestore';
import {getAuth, signInWithEmailAndPassword} from 'firebase/auth';

let FIRESTORE;
let AUTH;

// Firebase Console >> Authentication
const USER1 = {
  email: 'the.admin.guy@test.com', // USER THAT EXISTS IN FIREBASE AUTH
  password: 'let_me_in',
  uid: UID_FROM_FIREBASE_AUTH_FOR_THIS_USER
};

// Firebase Console >> Project Overview >> General >> Apps
//    (use existing app values or click Add app to create new WEB app)
const FIREBASE_CONFIG = {
  apiKey: VALUES_FROM_FIREBASE_APP_CONFIG,
  appId: VALUES_FROM_FIREBASE_APP_CONFIG,
  authDomain: VALUES_FROM_FIREBASE_APP_CONFIG,
  databaseURL: VALUES_FROM_FIREBASE_APP_CONFIG,
  messagingSenderId: VALUES_FROM_FIREBASE_APP_CONFIG,
  projectId: VALUES_FROM_FIREBASE_APP_CONFIG
};

const initializeFB = async () => {
  let fbApp = initializeApp(FIREBASE_CONFIG);
  FIRESTORE = getFirestore(fbApp);

  let USING_FIREBASE_EMULATOR = true;
  if (USING_FIREBASE_EMULATOR) {
    // I explicitly set "host" and "port" in firebase.json so that devices
    // on my local network can access the emulator:
    //        "emulators": {
    //          "functions": {
    //            "port": 5001,
    //            "host": "192.168.1.53"
    //          },
    //          "firestore": {
    //            "port": 5002,
    //            "host": "192.168.1.53"
    //          },
    //       ...
    //
    connectFirestoreEmulator(FIRESTORE, '192.168.1.53', 5002);
  }

  try {
    AUTH = getAuth();
    await signInWithEmailAndPassword(AUTH, USER1.email, USER1.password);
    let currUser = AUTH.currentUser;
    console.log(`Logged in with USER1 uid(${currUser.uid})`);
  } catch (ex) {
    console.error(ex.message);
    throw ex;
  }
};

const deleteDocs = async (collectionPath, field, compareOp, compareValue) => {
  let queryRef = query(
    collection(FIRESTORE, collectionPath),
    where(field, compareOp, compareValue)
  );
  let querySnap = getDocs(queryRef);

  console.log(`WHERE returned ${querySnap.size} records`);

  let batch = writeBatch(FIRESTORE);

  querySnap.forEach((docSnap) => {
    console.log(`DELETING ${docSnap.ref.id}`);
    batch.delete(docSnap.ref);
  });

  try {
    await batch.commit();
    console.log('Transaction successfully committed!');
  } catch (ex) {
    console.log(`Transaction failed: ${ex.message}`);
    throw ex;
  }
};

const main = async () => {
  console.log('>>> START LOADING Users - ', Date());
  await initializeFB();
  await deleteDocs('orders', 'closedDate', '<', new Date('2021/08/31'));
  console.log('>>> DONE - ', Date());
  process.exit(0);
};

main();