An Experiment in Modeling Billing Systems
Currently this is a small code sample to explore Ruby's Observable module and how it might behave with ActiveRecord and AASM.
When a BillItem is initialized, it registers a Bill object as an observer.
Whenever we save! on the BillItem, we notify the observer that a change has occured and to execute the appropriate function.
Bill receives this notification message and executes the update_total method, this updating the Bill total.
If you need to edit the schema or update the annotations, set ENVIRONMENT = 'development' in the init.rb file.
When testing, set ENVIRONMENT = 'test' and run rspec spec/.
We're using a SQLite3 in-memory database so all database connections sharing the in-memory database need to be in the same process. The database is automatically deleted and memory is reclaimed when the last connection to the database closes.