Broken Windows

Why does a team of smart people end up with a messy code base over time? We use great technologies and methodologies, but the reason for the mess often comes down to human nature.

Broken Windows theory explains how seemingly little problems can provide the foundation for a future disaster. People often unconsciously don't fix things because they think it’s ok to keep it messy, but these "broken windows" can lead to a whole host of bigger issues in your code base.

This presentation shows how Broken Windows theory can be applied to Software Engineering. It shows how to deal with broken windows in our software, deliver value and keep programmers happy.

Presented on LA Ruby September UnConference Meetup
http://www.meetup.com/laruby/events/129338842/

Transcript

1. Broken Windows Alexander Tamoykin http://alextamoykin.com
2. Agenda •What •Why •How
3. What is broken Windows?
4. What What ?
5. Lunch
6. Changed your mind ?
7. Just go with it
8. William Bratton
9. Simplified Code Example class SWE < ActiveRecord::Base! has_many :registrations! ! def go_to_conference! my_registration = registrations.find_by_swe_id id! my_registration.book! end! end
10. How do we get there ? class SWE < ActiveRecord::Base! has_many :flights! has_many :registrations! ! def go_to_conference! my_flight = flights.find_by_swe_id id! my_flight.book! my_registration.book = registrations.find_by_swe_id id! my_registration.book! end! end
11. Where do we stay ? class SWE < ActiveRecord::Base! has_many :flights! has_many :hotels! has_many :registrations! ! def go_to_conference! my_hotel = hotels.find_by_swe_id id! my_hotel.book! my_flight = flights.find_by_swe_id id! my_flight.book! my_registration = registrations.find_by_swe_id id! my_registration.book! end! end
12. What if the conference is sold out ? class SWE < ActiveRecord::Base! has_many :flights! has_many :hotels! has_many :registrations! ! def go_to_conference! my_registration = registrations.find_by_swe_id id! ! if my_registration.book! my_hotel = hotels.find_by_swe_id id! my_hotel.book! my_flight = flights.find_by_swe_id id! my_flight.book! end! end! end
13. What if there is no hotel ? class SWE < ActiveRecord::Base! has_many :flights! has_many :hotels! has_many :registrations! ! def go_to_conference! my_registration = registrations.find_by_swe_id id! if my_registration.book! my_hotel = hotels.find_by_swe_id id! if my_hotel.book! my_flight = flights.find_by_swe_id id! my_flight.book! end! end! end! end
14. Hard to change!
15. Is this easier to change ? class SWE < ActiveRecord::Base! …! def go_to_conference! register! book_hotel! book_flight! end! ! def book_flight! my_flight = flights.find_by_swe_id id! my_flight.book! end! ! def book_hotel! my_hotel = hotels.find_by_swe_id id! my_hotel.book! end! ! def register! my_registration = registrations.find_by_swe_id id! my_registration.book! end! end
16. How did it happen ? class SWE < ActiveRecord::Base! has_many :flights! has_many :hotels! has_many :registrations! ! def go_to_conference! my_registration = registrations.find_by_swe_id id! if my_registration.book! my_hotel = hotels.find_by_swe_id id! if my_hotel.book! my_flight = flights.find_by_swe_id id! my_flight.book! end! end! end! end
17. Human Nature • Survive • Adapt to the environment • Do what everyone else does
18. What’s the problem ? Cost to Change Technical Debt
19. What’s the problem ? Cost to Change Technical Debt
20. Why • Legacy Code • Time Pressure • It can’t be worse
21. Pragmatic Advise
22. How • Identify a broken window • Refactor it • Track it • Come back and do it right • Leave a comment
23. Do it! Before it’s too late
24. Concrete Examples • Write a missing test • Split a large class into smaller classes • Look at Code Climate • Delete dead code • Review a pull request • Take a fresh look tomorrow • Encourage your coworker to fix it • Incrementally refactor
25. Most Importantly
26. The End http://alextamoykin.com