Gradual Typing in Ruby - A Three Year Retrospective

Presented at RubyConf 2021

We began adopting gradual typing on Shopify's giant monolith almost 3 years ago. Today, we are running the monolith with great type coverage and even see some internal teams commit to stricter typing in their components.

The road to get here was not easy, though. We had to work with our developers to solve the right problems at the right levels of abstraction to ensure the adoption was healthy. This talk will go over some of the challenges and some of our wins along the way. It will also help you decide if gradual typing might work for your codebase and your team, as well.

Ufuk Kayserilioglu
Ufuk is the Engineering Manager of the Ruby Infrastructure and Ruby Types teams at Shopify and brings over 20 years of industry experience to the company for the adoption of better Ruby tooling and practices. He currently works remotely from Cyprus where he lives with his beloved wife and wonderful daughter.

Alexandre Terrasa
Alexandre has a PhD in computer science and specializes in typing specifications and implementations. He currently works as a Staff Engineer on the Ruby and Rails Infrastructure team at Shopify. He uses his expertise for the adoption of better Ruby tooling and practices including Sorbet and gradual typing to make the Shopify platform better for everyone. He previously worked as a core developer on the Nit language for which he implemented parts of the compiler, libraries and tools.

Transcript

1. Gradual Typing in Ruby A Three Year Retrospective Ufuk Kayserilioglu & Alexandre Terrasa Ruby and Rails Infrastructure
3. Why static gradual typing?
4. Ruby is dynamically typed
5. We love Ruby because it is dynamic
6. Static analysis is fast and powerful
7. Are we turning Ruby into another language?
8. The codebase is HUGE
9. Gradual typing is the best middle-ground
10. Human Challenges
11. How do we make it easy for teams?
12. What benefits do teams get?
13. How can we advertise the benefits?
14. Technical Challenges
15. Ruby is a very dynamic language
16. Classes and methods are created at runtime
17. Dependencies are black boxes ?
18. How we met the challenges?
19. Built experiments to test our hypotheses
20. typed: false no syntax errors no name errors
21. typed: true less no method errors
22. We were convinced it was the right choice
23. Built a lot of tooling to make it happen
24. RuboCop-Sorbet Rules for Sorbet adoption https://github.com/Shopify/rubocop-sorbet
25. Tapioca The swiss army knife of RBI generation https://github.com/Shopify/tapioca
26. RBI RBI generation framework https://github.com/Shopify/rbi .rbi
27. Sorbet Metrics Internal Sorbet Adoption Dashboard
28. Spoom Useful tools for Sorbet enthusiasts https://github.com/Shopify/spoom
29. Made progress visible
30. Sorbet Metrics
31. Show areas of concern
33. Track general adoption in projects
34. Track general adoption by users
35. Core-to-true dashboard
36. Use metrics to motivate
37. Treated developers as customers
38. Periodic surveys
39. Internal guides and documentation
40. Always ready to help devs having problems
41. Learnings
42. Build Measure Learn
43. Devs are customers We are building a product for them
44. typed: ignore = typed: debt # -- foo.rb -- # typed: ignore class Foo end # -- bar.rb -- # typed: false class Bar < Foo end $ dev tc bar.rb:4: Unable to resolve constant Foo 3 | class Bar < Foo ^^^
45. Keep things up-to-date
46. Enforce stricter typing
47. Enforce up-to-date DSL RBIs
48. Enforce up-to-date gem RBIs
49. Be patient
54. The right tooling is an accelerator
55. Fill the gaps
56. Do NOT get in the way! Ramp up gently
57. Happy Typing! -- The Ruby Infrastructure team