No Static Types? No Problem!
summary
A small Rails app called the cookie_cutter app has a rake batch that sometimes passes a recipient string instead of a Person and charges payment before crashing; Sorbet catches that mismatch as a runtime and editor error by failing at the method call, RBS/YARD give editor hints, and the new literal gem enforces checks at initialization. Fixes shown include coercions (string → Person, HashWithIndifferentAccess), GlobalID lookups, a refactored checkout object that validates in initialize, and the null object pattern to avoid late failures.
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chapters (11)
- 0:00Introduction
- 15:07What is a type in Ruby
- 27:20Static type systems overview
- 35:10Caller vs static typing
- 48:15Break and return hook
- 52:31Ruby type errors in production
- 1:00:20Data coercion techniques
- 1:18:58Object design and encapsulation
- 1:33:22Polymorphism and null objects
- 1:43:22Static typing pros and cons
- 1:48:44Q&A
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