Ruby Idioms

Iron Laws

1. Prefer simple objects over metaprogramming
2. Raise exceptions for failures; return values for expected branches
3. Keep mutation narrow and obvious
4. Wrap third-party APIs behind project-owned adapters
5. Avoid global state and hidden thread-local coupling
6. Consider it for simple single-argument blocks when clarity permits
7. Prefer pattern matching for complex data destructuring
8. Enable YJIT in production (Ruby 3.2+; Rails 7.2+ enables by default on Ruby 3.3+)

Ruby 3.4+ Features

The it Keyword