firebase-emulators.md

Firebase Emulators

Instead of running just the functions emulator, the full suite of emulators can be used. You can find out more at https://firebase.google.com/docs/emulator-suite

Note: If your code accidentally invokes non-emulated (production) resources, there is a chance of data change, usage and billing. To prevent this, you might opt in to use a Firebase project name beginning with demo- (e.g. demo-staging) in which case no production resources will be used.

This might entail some code changes as well, to enable the emulation, e.g.

In src/index.tsx:

// Enable the functions emulator when running in development at specific port
if (process.env.NODE_ENV === "development" && window.location.port === "5000") {
  firebaseApp.firestore().useEmulator("localhost", 8080);
}

or to account for changed and/or deprecated Firebase client API, e.g.

// deprecated
// import firebase, { UserInfo } from "firebase/compat/app";
// use instead
import firebase from "firebase/compat/app";
type UserInfo = firebase.UserInfo;

You can start the emulators in a manner that can persist the data locally:

npx firebase "emulators:start" --import=./tmp --export-on-exit

You should be greeted with

All emulators ready! View status and logs at http://localhost:4000

That's the location you can access and manage the running emulators.

If run as above, the data between emulator runs should be persisted at:

tmp/firebase-export-metadata.json
tmp/firestore_export