Takeaway Challenge

Week 2 Challenge at Makers Academy

This challenge demonstrates use of TDD, OOD, OOP, Ruby, RSpec, Gems(Guard, Twilio)

Update 9 Nov 19:00:

The class OrderDetails was not required. So has been removed. Also, the responsibilities of takeaway were reduced significantly from early versions.

Challenge

• list of dishes with prices
• placing the order by giving the list of dishes, their quantities and a number that should be the exact total. If the sum is not correct the method should raise an error, otherwise the customer is sent a text saying that the order was placed successfully and that it will be delivered 1 hour from now, e.g. "Thank you! Your order was placed and will be delivered before 18:52".
• The text sending functionality should be implemented using Twilio API. You'll need to register for it. It’s free.
• Use twilio-ruby gem to access the API
• Use a Gemfile to manage your gems
• Make sure that your Takeaway class is thoroughly tested and that you use mocks and/or stubs, as necessary to not to send texts when your tests are run
• However, if your Takeaway class is loaded into IRB and the order is placed, the text should actually be sent

Running the Program

$ irb
$ require('./irbsetup')

Since the Twilio secure keys are private, that aspect of the system will not work outside of my laptop.

Domain Model

Based on the above text, there are a number of implications that are not specified. Reading inbetween the lines, the brief I will work against is:

There is a takeaway resturant with a menu, that contains a list of dishes which have prices. Customers can place an order by specifying exactly what they want and the cost they are expecting to pay for them based on the menu information. Asssuming the customer places an order correctly, they will be sent a text message. The text message needs to display a certain amount of text confirming the order is on its way. The text message can show the order details if appropriate.

From the domain model, I have extracted 6 or possibly 7 classes. They are:

• TakeawayRestaurant
• Menu
• Dish
• Order
• Customer
• TextMessage
• OrderDetails/LineItem??

Class - Takeaway Restaurant

Responsiblities	Collaborators
Have Menu	Customer
Create text message	Menu

                     | Message
                     | Order

Class - Menu

Responsiblities	Collaborators
Show dishes	Customer

                     | Dish

Class - Dish

Responsiblities	Collaborators
Show name and price	Customer

                     | Menu

Class - Order

Responsiblities	Collaborators
List dishes	Customer
List Customer name	Takeaway
List total price

Class - Customer

Responsiblities	Collaborators
Place order	Takeaway
Receive text message	Order

Class - Text Message

Responsiblities	Collaborators
Send Message	Takeaway
List order details	Customer
Create Message	Order

###Lessons Learned

• This challenge was important because it allowed me to learn how to integrate into an API. Fortunately Twilio's documentation is very good, so it was not a big struggle to get it setup.
• While testing the app, it was important to prevent the app from sending text messages. This was a useful lesson in providing additional layers of abstraction, so that the interaction with Twilio was not a dependency of the app.