Solution to Cabify Ruby Code Challenge

Hi Cabify Team, in this repository I want to share my solution to the Ruby Code Challenge. Here you will find some explanations and considerations about the code.

Class Diagram

This is the class diagram that I chose to solve the exercise. With this architecture it is possible to connect to a database and extend the store with more products or rules in a quick and easy way. The exercise is composed of the following classes:

### Product This class contains the product information it has three attributes: code, name and price as well as two methods::

• to_s: returns the product in a beautiful table.
• to_a: returns product attributes values as an array [ @code, @name, @price ].

Store

The store class is responsible of storing the products available in the store. Within this class you will find the @inventory attribute consisting of a hash of products, each product has the product key code as a symbol and value as an object from the class product. This class has methods such as:

• find returning a product from the store if exists or nil.
• add_new_product this can extend the inventory creating a new product for the store.
• list that returns store's products in a fancy table and some other methods necessary for internal operations of the checkout process.

Item

This class is associated with one checkout process. Each object from this class saves the code from one product in the store and a price attribute that can change depending of which promotion or discount rule is applied to the item.

Rules

Departments are creating different discounts to implement in the store. Each promotion rule corresponds to one specific class, all of these classes must have a special characteristic and an apply method. This method will update the item's price depending on the values, rules and structure for each discount. The next rules are implemented in this repository:

1. Discount rule: If the checkout process has three or more T-shirts items, it will discount 1.0€ to each of them.

2. Two for one rule: On VOUCHER items, pay one take another for free.

3. Free item rule: I made this code with ❤️ and I built this as a gift. This rule shows how easy it is to extend the pricing rules with a new discount program.

Checkout

Checkout class is where the magic happens, this class has a special initialize method that receives a variable number of pricing rules. In this method the checkout process creates the initial products for Cabify's Store and builds a store object with them. Each checkout object has a set of items as an array. With this special configuration we can control the price for each item depending on the rules given to checkout's constructor. scan method makes a validation for the product code returning trueor false when searching for the product code in the store. total method calls each rule's apply method to update items price according to each rule configuration.

Unit Test

This is production code, therefore I decided to include some unit test cases that you can check in the test folder for each class.

CLI

In addition I built a Command Line Interface, run the cli.rb file and remember to install the terminal-table gem. You can find the next options at the CLI:

1. Inventory: Get all the products from the store.
2. Find product: Find a product given a specific code.
3. Create product: Create a new product for the store.
4. Scan product: Add a new item to checkout process.
5. Total: Get the total value for checkout process after applying all the rules.
6. Exit: Finish the program.