This document introduces Test Driven Development (TDD) using Ruby on Rails. It discusses why testing and TDD are important, including allowing for refactoring and delivering working code. The Red-Green-Refactor TDD process is explained as writing a test, seeing it fail, writing code to pass the test, and refactoring. RSpec is recommended for testing. The document then provides an example project for a restaurant menu and orders system to demonstrate TDD. Attendees are instructed to work in pairs using TDD to build recommendation and social features for the project.

1. WTF is TDD
A journey to writing awesome code, one test at a time

2. WTF we'll be covering
● What is testing and why you are hurting the
world by not doing it
● What is TDD, why do it, and why it's better
than writing tests AFTER you've written
your code
● See code that was developed using TDD
● Extending this code

3. Who TF is this guy?
● Steven Nunez (@_StevenNunez)
○ Junior Developer at Cyrus Innovation
■ AWESOME PLACE!
● Agile/TDD All day, E'ryday
○ Organizer of Unearth Ruby
■ http://www.meetup.com/unearthruby/
○ Co-Organizer of NYC Rubyist Roundtable
■ http://www.meetup.com/nycruby/

4. Stuff you need to F'ing know
How to read this:
class Order
attr_reader :items
def initialize
@items = Hash.new(0)
end
def add(item)
items[item] += 1
end
end

5. What Is Testing
The Act of isolating parts of your code with a
known state to ensure it works as expected.
Setup follows AAA principle:
Arrange
Act
Assert

6. Types of testing
● End to end tests/ Acceptance tests
○ Here there be Cucumbers. Capybara, Webrat
○ Used to ensure system works as a whole
● Unit Tests
○ Rspec, Test::Unit, Minitest
○ View tests
○ Controller tests
○ Model tests

7. Why Test
● Lets you know when things broke
○ You'd be surprised how code works
● Allows for courageous refactoring
● Gives documentation on how your code is
SUPPOSED to work
● It is your duty to deliver working code.

8. Testing basics
We'll be using Rspec...
http://rspec.info/
https://github.com/rspec/rspec-
expectations#built-in-matchers
Codey Code! ----> http://bit.ly/PUwQLf

9. What is Test Driven
Development?

10. Why do TDD?
● Forces you to think small
○ You have a clear objective
● Less thoughts to juggle
○ All you know is how you want it to work
● Leads to modular code
○ Each part of your code does one job
● Write less code
● Increase documentation
● It makes you happy!
○ Red, Green, REFACTOR!
http://edu.mkrecny.com/thoughts/be-nice-to-programmers

11. How to TDD
Red Green Refactor
1. Write a test.
2. Watch it fail.
3. Write code to pass your test.
4. Look for ways to make your code more
expressive
5. GOTO 1

12. Our project
Our client is developing a social network based for his Restaurant customers. He'd want to eventually have people with
similar food interests meet up and discuss how his food changed their lives.
● A few features he wants are:
○ The ability to have users discover new foods based on ingredients they love (Bacon!)
○ The ability to find users with similar food interests. The system will automatically share their phone
numbers with each other. (He thinks they'll be ok with this)
What do you need first?
I need a way to capture customer orders based on their menu.
Things we built
A Menu with Menu Items in it.
The Items need to have a name, price, calorie count, and ingredients
Orders consist of a menu item, and a quantity.
Orders can calculate their total

13. Your task!
Pair up and work on getting the
recommendation engine up.
Noobs, pair up with Wizards.
TDD ONLY!
https://github.com/StevenNunez/FinerDiner

14. Questions!

15. Task
Menu#recommendations(:bacon)
# => [:bacon_cheeseburger, :blt, :bacone ]
Socializer#socialize!
# customer_1.hook_up(customer_2)

16. Resources
https://www.relishapp.com/rspec
http://pragprog.com/book/achbd/the-rspec-
book
Practical Object Oriented Design by Sandy
Mentz
http://www.poodr.info/

17. THANKS!