Example testing Firebase services with Mocking vs Emulation

Example repo for the Why mocking sucks post illustrating testing Firebase services with mocking vs with the Firebase emulator.

Prerequisites

• Python
• uv

Getting Started

Create a Firebase project and download your service account key file from your project configuration. Paste the contents of the service account key into the service_account_key_example.json file.

Test with Mocking

Use the following command to run mocked tests

uv run pytest firebase_test_with_mocking.py

Test with Firebase Emulation

Install the Firebase CLI.

npm install -g firebase-tools

Authenticate the CLI

firebase login

Initialize the project.

firebase init

Initialize Firebase Emulators.

firebase init emulators

Start the emulator.

firebase emulators:start

Run the test against the emulator

uv run pytest firebase_test_with_emulator.py