Stubs, Jobs, Mailers & the Whole Suite

Faking the boundary, never the code under test

Module 12 already showed you this trick in the payments story — here it is again, because it's the single most important idea for testing anything that talks to the outside world. apps/pawwalk-api has no real Stripe account configured, and this course never asked you to make one. So how does payments_test.rb prove PaymentsController#create calls Stripe correctly, with zero real network calls?