Testing and Local Development

Integration Tests

The most reliable way of testing your project is to create a separate Firebase project and configure your tests to use it instead of the your production project. For example, you could have multiple Firebase projects depending on your use-case:

  • my-project-dev: used for developers while they develop new features
  • my-project-int: use by CI/CD pipelines
  • my-project-staging: used to present upcoming to stake holders
  • my-project: used for production

Using the Firebase Emulator Suite

For an introduction to the Firebase Emulator suite, please visit the official documentation: https://firebase.google.com/docs/emulator-suite

To use the Firebase Emulator Suite, you must first install it.


Only the Auth Emulator is currently supported. The other Emulators are not yet available, and side-effects could occur.

Auth Emulator

In your project, create a firebase.json file and make sure that at least the following fields are set (the port number can be changed to your requirements):

  "emulators": {
    "auth": {
      "port": 9099

The Firebase Admin SDK automatically connects to the Authentication emulator when the FIREBASE_AUTH_EMULATOR_HOST environment variable is set.

$ export FIREBASE_AUTH_EMULATOR_HOST="localhost:9099"

With the environment variable set, Firebase Admin SDKs will accept unsigned ID Tokens and session cookies issued by the Authentication emulator (via verifyIdToken and createSessionCookie methods respectively) to facilitate local development and testing. Please make sure not to set the environment variable in production.

When connecting to the Authentication emulator, you will need to specify a project ID. You can pass a project ID to the Factory directly or set the GOOGLE_CLOUD_PROJECT environment variable. Note that you do not need to use your real Firebase project ID; the Authentication emulator will accept any project ID.