FIRESTORE: a node/JavaScript command-line script that visits all docs in a Firestore collection and updates them with the given values (in this example, we set/add an "enabled" field to TRUE) -- uses the Firebase Web SDK v9 API

firestore_add_field_to_all_docs_in_collection.js

/**
 * firestore_add_field_to_all_docs_in_collection.js
 *
 * 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 `visitDocs`.
 *
 * NOTE: this code works with the Firebase Web SDK v9 API.  Earlier revisions used the v8 API.
 *
 * To run: node firestore_add_field_to_all_docs_in_collection.js
 *
 *   Alternatively, you can create a "script" in package.json:
 *     "scripts": {
 *          ...
 *        "add_field_to_fs": "node tools/cleanup/firestore_add_field_to_all_docs_in_collection.js"
 *     }
 *
 *   and then run the script with:  npm run firestore_add_field_to_all_docs_in_collection.js
 */

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: 'mr.magoo@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 () => {
  // USE YOUR FIREBASE PROJECT SETTINGS:
  //   Firebase Console >> Project Overview >> Apps
  //    >> (select or "Add App" web app) >> Config
  const firebaseConfig = {
    apiKey: 'xxx',
    appId: 'xxx',
    authDomain: 'xxx',
    databaseURL: 'xxx', // use project value for cloud, or use emulator values such as "http://192.168.1.53:5001/" (see USE_FIREBASE_EMULATOR below)
    messagingSenderId: 'xxx',
    projectId: 'xxx'
  };

  let fbApp = initializeApp(firebaseConfig);
  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 visitDocs = async (
  collectionPath,
  field = null,
  compareOp = null,
  compareValue = null,
  updateValue
) => {
  let collRef = collection(FIRESTORE, collectionPath);

  if (field && compareOp) {
    collRef = query(collRef, where(field, compareOp, compareValue));
  }

  let querySnap = getDocs(collRef);

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

  let batch = writeBatch(FIRESTORE);

  querySnap.forEach((docSnap) => {
    console.log(
      `UPDATING ${docSnap.ref.id} with: ${JSON.stringify(updateValue)}`
    );
    batch.update(docSnap.ref, updateValue);
  });

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

const main = async () => {
  console.log('>>> START LOADING Users - ', Date());
  await initializeFB();

  // add/set an "enabled" field to true for all docs in the 'users' collection
  await visitDocs('users', null, null, null, {enabled: true});

  console.log('>>> DONE - ', Date());
  process.exit();
};

main();