Ruby DeRailed Pt 1: Fast Tests

In this talk I analyze what in the Rails environment that causes slow tests and what we can do to fix it.

Transcript

1. Ruby DeRailed Myles Megyesi Software Craftsman @mylesmegyesi Friday, September 27, 13
2. Let’s talk about TDD Friday, September 27, 13
3. Write Test Run It Write Code Run it Refactor Run it Friday, September 27, 13
4. Write Test Run It Write Code Run it Refactor Run it Friday, September 27, 13
5. Write Test Write Code Run it Refactor? Friday, September 27, 13
6. Omakase Rails produces slow test suites Friday, September 27, 13
7. Attempt #1: Abstracting your Application Away from Rails Friday, September 27, 13
8. Omakase Rails App Controllers Views Models Business Logic Friday, September 27, 13
9. Extraction Controllers Views Models Business Logic Friday, September 27, 13
10. Rails App Controllers Views Friday, September 27, 13
11. Gem Models Business Logic Friday, September 27, 13
12. Controllers Views Models Business Logic Controllers Views Models Business Logic Omakase Rails App Extraction Friday, September 27, 13
13. Put it to the test! Friday, September 27, 13
14. User-Facing App Controllers Views Controllers Views Admin App Shared Gem Models Business Logic Business Logic Friday, September 27, 13
15. Fail Friday, September 27, 13
16. Our Rails apps still had a lot of code Friday, September 27, 13
17. User-Facing App Views Controllers Admin App Shared Gem Presentation Logic App Specific Use Cases Views Controllers Presentation Logic App Specific Use Cases Generic Use Cases Business Logic Models Friday, September 27, 13
18. The shared gem still depended on the Database Friday, September 27, 13
19. 2 Lessons Learned • Extraction is not enough • Don’t depend on external services Friday, September 27, 13
20. Back to the drawing board Friday, September 27, 13
21. Preloading Friday, September 27, 13
22. Rails “environment” • Load the Rails framework • Load all dependencies in the Gemfile • initialize! ★ Load all code in Rails Engines Friday, September 27, 13
23. Rails “environment” loading is linear over time Friday, September 27, 13
24. 0 1.5 3 4.5 6 9 13 20 25 39 53 Empty Rails App Friday, September 27, 13
25. Active Record Friday, September 27, 13
26. Attempt #2: Optimize the Rails environment Friday, September 27, 13
27. Lazy-loading over Preloading Friday, September 27, 13
28. Don’t load all of Rails require 'rails/all' require 'action_controller/railtie' require 'sprockets/railtie' Friday, September 27, 13
29. Bundler.require(:default, Rails.env) Don’t load dependencies Friday, September 27, 13
30. Bundler.require(:default, Rails.env) Don’t load dependencies Friday, September 27, 13
31. config.active_support.bare = true Don’t load all of Active Support Friday, September 27, 13
32. Spec Helpers • spec_helper.rb • rails_spec_helper.rb Friday, September 27, 13
33. The Repository Pattern Friday, September 27, 13
34. Results Friday, September 27, 13
35. 0 100 200 300 400 Attempt #1 Attempt #2 Attempt #2 Projected Total Test Suite Time Attempt #1: 4853 examples, 377.13 seconds Attempt #2: 1706 examples, 7.19 seconds Attempt #2: Projected to 4853 examples, 20.45 seconds Friday, September 27, 13
36. Time to Run One Test Attempt #1: 18.195 seconds, 69 gems Attempt #2: 1.580 seconds, 40 gems 0 5 10 15 20 Attempt #1 Attempt #2 Friday, September 27, 13
37. Fast Feedback! Friday, September 27, 13
38. Rails “environment” loading is still linear Friday, September 27, 13
39. 0 1.5 3 4.5 6 10 13 20 25 40 53 Attempt #2 Empty Rails App Friday, September 27, 13
40. Contextual Overhead Friday, September 27, 13
41. Thank you! @mylesmegyesi Friday, September 27, 13