Subscription based web crawler, which checks if a badminton/tennis court becomes free in a time slot/date provided by user when subscribing. It works by parsing HTML content of a court reservation service twojtenis.pl. If a court becomes free, a notification is send using service workers. It is designed to be deployed in Google Functions. It is the back-end part for the front-end available here.
The entry point to this app is pipeline.js
All the keys and passwords used in the code have been deactivated.