What problem does it solve? Verifying changes to a Firebase-backed logistics app is risky without a safe, repeatable test environment. This Skill explains how to run the BMRC test tiers against the Firestore emulator, add new invariant tests, and verify changes end-to-end without ever touching production data. ## Core Features & Use Cases - Tiered test commands: Choose the right suite for each change, from offline pure-logic tests to invariant integration suites, fast-check property tests, a 15-week semester simulation, and Playwright e2e tests. - Emulator safety guard: A hard guard refuses production-shaped config (non-demo projects, real credentials, missing emulator host), so tests can never touch live Firestore data. - Invariant test recipe: A step-by-step pattern for adding new invariant tests (e.g. INV-13) that drive the real app/lib helpers through the real Firestore client and assert on resulting documents. - Use Case: After changing the receiving logic, run npm run test:invariants and npm run test:simulation against the emulator, then drive a full checkout-to-check-in flow in the dev server to confirm dashboards and logs update correctly. ## Quick Start Ask the assistant to run the BMRC invariant test suites against the Firestore emulator and report which tiers pass before shipping your change.
