The Loop & Minitest

You've been running this the whole time

Every checklist since module 09 has told you to run bin/rails test before moving on. Thirteen modules, sixty-six tests, and you've watched the dots print green every single time — without ever reading what a single one of those tests actually says. That changes now. This module doesn't add a feature to PawWalk. It teaches you to read, and then write, the suite that's been quietly guarding every feature you already built.

The JS apps in this monorepo call their green gate the loop — typecheck, lint, test, run after every change, before anything ships. PawWalk has the exact same idea in Ruby clothes: bin/rails test and bin/rubocop. Every feature from auth to payments to live tracking landed in this app gated on both commands passing. A test suite isn't homework bolted on afterward — it's the reason you've been able to add fourteen modules of features on top of module 09's foundation without anything from module 09 quietly breaking.