Ruby Knowledge
Authoritative resource map for Ruby development. Use these sources rather than searching broadly.
Never use these sources:
-
ruby-doc.org
-
apidock.com
Official Documentation
Primary source: https://docs.ruby-lang.org/en/
Other Useful Resources
-
https://rubyreferences.github.io/rubychanges/ - Version-by-version changelog with examples
-
https://railsatscale.com/ - Shopify engineering blog (Latest updates on Ruby and its toolings)
Core & Standard Library
Term Meaning
Default gem Ships with Ruby, cannot uninstall
Bundled gem Ships with Ruby, can uninstall/replace
Standard library Part of Ruby itself, not a gem
Version Documentation Standard Library
3.2 https://docs.ruby-lang.org/en/3.2/ https://docs.ruby-lang.org/en/3.2/standard_library_rdoc.html
3.3 https://docs.ruby-lang.org/en/3.3/ https://docs.ruby-lang.org/en/3.3/standard_library_rdoc.html
3.4 https://docs.ruby-lang.org/en/3.4/ https://docs.ruby-lang.org/en/3.4/standard_library_md.html
4.0 https://docs.ruby-lang.org/en/4.0/ https://docs.ruby-lang.org/en/4.0/standard_library_md.html
master https://docs.ruby-lang.org/en/master/ https://docs.ruby-lang.org/en/master/standard_library_md.html
Typing Ecosystem
Two type definition formats exist in Ruby:
-
RBI - Sorbet's format. Uses Ruby DSL syntax (sig { ... } ) in .rb and .rbi files.
-
RBS - Official Ruby format (Ruby 3.0+). Dedicated syntax in .rbs files or inline as comments.
Sorbet Ecosystem
Sorbet is a static and runtime type checker for Ruby, maintained by Stripe. Key companion tools:
-
Tapioca - Generates RBI files for gems and DSLs (Rails, ActiveRecord, etc.)
-
Spoom - Coverage analysis, strictness bumping, dead code detection, signature migration
RBS Ecosystem
-
rbs - Official CLI for working with RBS files (prototype, list, methods)
-
Steep - Type checker that uses RBS
RBS Inline Comments
Sorbet supports RBS-style inline type annotations using #: comment syntax. This eliminates the need for separate .rbi files or verbose sig blocks.