Writing Better, Type-safe Code with Sorbet

Summary

Ruby repositories can hide unsafe method calls and ambiguous data shapes when types are inferred from variable names alone. Sorbet static type checking addresses these risks with method signatures, typed structs, enums, and interfaces. It can flag a potentially nil return before a chained call, distinguish database output fields from input fields, and enforce contracts for synchronous and asynchronous indexers in a dependency-injected hexagonal structure. The article also describes Sorbet’s gradual typing, including five strictness levels and namespace-by-namespace adoption using the minimum typed level of true. The stated conclusion is that enforced type safety catches errors unit tests may miss and helps prevent unsafe code from reaching production.

Takeaways

1. 1

   Sorbet can reject a chained call when a method signature permits nil, reducing reliance on trivial unit tests for every return case.

2. 2

   Typed structs distinguish input ads from database-returned ads, while enums constrain state values and make nullable fields explicit.

3. 3

   Sorbet interfaces require synchronous and asynchronous indexers to implement the expected method and return types, supporting dependency injection and polymorphism.