Remember to bundle install before you get started!
Run the program by executing the exutable file:
$ ruby bin/process_orders
This will start up the command line interface which will prompt you to enter the path of a file to process, or to enter the default command to process the default file, input/orders.csv.
To skip the (super fun) bells and whisltes of the CLI, you can comment out line 7 of the executable file and comment line 11. Then, execute the file again, with and argument to specify a particular file of orders to process, or without an argument to process the default file, input/orders.csv
$ ruby bin/process_orders /path/to/file
or
$ ruby bin/process_orders
Your processed orders will be written to the output/ directory.
Tests are written with RSpec. To run the test suite, run rspec from the command line.
The OrderProcessor class is designed as the public-facing API of this program.
OrderProcessor.processThe call to .process is wrapped up in a nifty CLI, but the OrderProcessor class stands on its own and does the heavy lifting of this application.
The driving force behind OrderProcessor is the RedemptionCalculator class. This is a service class whose responsibility it is to apply super sweet (pun intended) deals to a customers orders and calculate their final chocolate order.
OrderProcessor also relies on the OutputGenerator class, which writes successive lines to the resulting CSV file.
The Order class produces objects describing an initial order, before processing.
The list of available chocolates and the rules describing free chocolates per order are stored in, and read from, YAML files. This ensures that we are keeping this data in one central location, so it will be easy to update in the future. It also keeps the applicatio in line with the Single Responsibility Principle––it is not the job of the Order class to know what chocolates are on offer, or what redemption rules to apply to a given order, nor is it the job of the RedemptionCalculator whose sole responsibility it is to calculate final orders.
The test suite focuses the public-facing OrderProcessor.process method, and thouroughly tests the RedemptionCalculator, since that is the class the does most of the heavy lifting. The test suite aims to focus on testing desired behavior, not implementation. Consequently, the OutputGenerator class is not tested since it is not a stand-alone class. It functions only within the context of the OrderProcessor class. Successfull OrderProcessor tests ensure that the OutputGenerator is behaving as expected.