This document outlines 10 commandments for Ruby programmers. The commandments include avoiding coupling domain objects with frameworks, not stealing and pasting code, avoiding nil, not using if/else statements, not mocking in tests, not taking tests in vain, refactoring daily, pairing with other programmers, challenging oneself, and avoiding bad practices. The document is presented by Emilio Gutter, a Ruby programmer and founder of 10Pines, sharing his expertise and experience.

1. THE TEN
COMMANDMENTS
of the ruby programmer

2. I AM EMILIO A RUBY PROGRAMMER
Software developer +15 yrs
10Pines founder
Agiles community founding member
agiles 2012 conference co-chair
husband, father and homeBrewer

3. I. Thou shalt have no
domain objects coupled
with thy frameworks

4. class Speaker < ActiveRecord::Base
!
devise :omniauthable,
:omniauth_providers => [:facebook]
!
def approve_session(session)
# do something
SessionMailer.approve(speaker: self,
session: session).deliver
end
!
end

5. II. THOU SHALT NOT
STEAL & PASTE CODE

6. public List selectPending(List registrations) {
!
List pending = new ArrayList();
for (Registration registration: registrations) {
if (!registration.isPaid()) {
pending.add(registration);
}
}
return pending;
}

7. !
def select_pending(registrations)
registrations.reject(&:paid?)
end
!
!

8. class SessionsController < ApplicationController
!
def create
!
@session = Session.new(session_params)
!
if @session.save
redirect_to my_sessions_path,
notice: 'Session created successfully'
else
render :new
end
!
end
end

9. class Program
!
def find_by_author(author)
!
sessions = Session.where(author: author,
approved: true)
!
if sessions.empty?
# do something
else
# do something
end
end
!
end

10. III. THOU SHALT
NOT USE NIL

11. class AttendeePresenter
!
def phone_number
!
unless self.address.nil?
unless self.address.phone_number.nil?
self.address.phone_number
else
'Phone number not present'
end
else
'Address not present'
end
end
!
end

12. class Attendee
def initialize(address)
if address.nil?
raise ArgumentError, 'Address is required'
end
@address = address
end
!
def address
@address || UnknownAddress.new
end
!
def phone_number
Optional.new(@address).
within {|address| address.phone_number}
end
end

13. IV. THOU SHALT
NOT USE IF

14. class BankAccount
!
def process a_transaction
!
if a_transaction.type == :purchase
# charge transaction fee
else
# assume refund
end
end
!
end

15. class BankAccount
!
def process a_transaction
a_transaction.process self
end
!
def process_purchase a_transaction
# charge transaction fee
end
!
def process_refund a_transaction
# refund transaction fee
end
!
end

16. class Purchase < Transaction
!
def process a_payment_method
a_payment_method.process_purchase self
end
end
!
class Refund < Transaction
!
def process a_payment_method
a_payment_method.process_refund self
end
end

17. V. THOU SHALT
NOT MOCK

18. require 'spec_helper'
!
describe Registration do
!
it 'pays a registration' do
!
attendee_id = 1
a_registration = double("Registration")
an_attendee = double("Attendee", registration: a_registration)
!
allow(Attendee).to receive(:find) { an_attendee }
!
expect(a_registration).to receive(:paid=).with(true)
expect(a_registration).to receive(:save).and_return(true)
!
expect_any_instance_of(PaypalAccount).to receive(:process)
!
Registration.pay(attendee_id)
!
end
end

19. VI. THOU SHALT NOT TAKE
THY TESTS
IN VAIN

20. VI. THOU SHALT NOT TAKE
THY
IN VAIN
VII. REMEMBER TO
REFACTOR EVERY DAY

21. VI. THOU SHALT NOT TAKE
THY
IN VAIN
VII. REMEMBER TO
REFACTOR
VII. THOU SHALT BEAR YOUR
FELLOW PROGRAMMERS
AND PAIR WITH THEM

22. IX. CHALLENGE
HONOUR
/[RUBY|RAILS|.*]/
FATHER AND MOTHER

23. X. NO GRAVEN
PRACTICES

24. QUESTIONS?
comments, critics,
compliments

25. THANKS!!!
email: egutter@10pines.com
twitter: @10pines
site: dev.10pines.com
blog: blog.10pines.com