Testing Shopify Apps in Rails

Let's talk for a bit about testing embedded Shopify Apps. With unit tests everything is straightforward. But how would you write integration and system tests for the app that is rendered in iframe? Especially now, when it uses JWT instead of cookies for Shop authentication? 🤯The approach I use allows to skip the iframe, fallback to cookies and write integration and system tests as we normally do in Rails. Let's take a look how to implement that step by step.