Shopify app_gem error test

This repo creates a reduced test case for a 500 error that happens at the same time as any invalid token error.

More details can be found in this issue: Shopify/shopify_app#1536

Setup

To get set up with this repo, clone and then:

1. Run bundle install
2. Create an app in the Shopify Partners dashboard
3. Create a .env file in the root of the project and add the following credentials

HOST=http://localhost:3000
SHOPIFY_API_KEY=<Your Shopify API key>
SHOPIFY_API_SECRET=<Your Shopify API secret>

4. Run the migrations

rails db:migrate

5. Run the app

rails server

6. Go to http://127.0.0.1:3000

Explaination

The app will attempt to fetch a list of products in the ProductsController that inherit from the AuthenticatedController. In app/views/home/index.html.erb I am purposely using an invalid token.

On the server side, in AuthenticatedController I am trying to rescue this error and return a 400 error. Eventually, this would be a 401 error to which I would add a re-authentication header. Unfortunately, I can't because it gets overridden by a server (500) error (see the error mentioned above for a full stack trace). I have tried rescuing from the ApplicationController without luck as well.

Notes

I've noticed that sometimes there is another error that happens on the client side even before the fetch. If this happens, just refresh.