Adding Tests to Your Firebase Studio Project

Most Firebase Studio projects ship with zero tests. This means every change is a gamble — you might fix one thing and break three others without knowing until a user reports it. Tests are automated checks that verify your app works correctly. They run in seconds and catch bugs before your users do.

Use the Firebase Local Emulator Suite for all testing — run Firestore, Auth, and Functions emulators locally. Write Jest or Vitest tests against the emulator. Test security rules with the Firebase Rules Unit Testing library (firebase-admin testing utilities)

Security rules testing is the highest priority — verify that unauthenticated requests fail, users can only read their own data, and malformed writes are rejected. Test Cloud Functions with the Functions emulator before deploying. Test that Firestore listeners are properly cleaned up on component unmount

Unit tests check individual functions in isolation — does this function calculate the right total? Integration tests check that multiple pieces work together — does submitting this form save to the database? End-to-end (E2E) tests simulate a real user — can someone sign up, log in, and complete a purchase? Start with E2E tests for your most critical flows, then add integration tests for your API endpoints.

Set up your tests to run automatically on every code push using GitHub Actions or a similar CI service. This way, you'll know immediately if a change breaks something. A basic CI pipeline runs your tests, checks for TypeScript errors, and builds the project. If any step fails, the push is flagged before it reaches production.