This spree extension was created for a technical test from a developer's job
Add this extension to your Gemfile with this line:
gem 'spree_product_out_stock', github: 'tucocorp/spree_product_out_stock', branch: '3.1-stable'
branch option is important: it must match the version of Spree you're using.
For example, use
3-1-stable if you're using Spree
Install the gem using Bundler:
Restart your server. If your server was running, restart it so that it can find the assets properly.
Now you can go to you_root_path:3000/admin (Ex: localhost:3000/admin) and Enter your access key.
Finally go to reports > Products ran out of stock report. if you see, you would select the range of date from products ran out of stock
NOTE: If you are trying to see the products and you have default spree setting, you must have to change the stock from products, because all the products have stock > 0.