SkillHub

ruby

v1.0.1

Write reliable Ruby avoiding mutable string traps, block pitfalls, and metaprogramming bugs.

Sourced from ClawHub, Authored by Iván

Installation

Please help me install the skill `ruby` from SkillHub official store. npx skills add ivangdavila/ruby

Quick Reference

Topic File
Mutable strings, object equality objects.md
Proc vs lambda, return behavior blocks.md
Visibility, method_missing methods.md
Array/hash mutation traps collections.md
define_method, eval traps metaprogramming.md
ActiveRecord, N+1, callbacks rails.md

Critical Rules

  • Strings are mutable — s = "hi"; s << "!"; t = s means t also has "!"
  • == vs equal? vs eql? — == value, equal? identity, eql? hash equality
  • Default hash value is shared — Hash.new([]) shares same array, use block form
  • return in proc returns from enclosing method — use lambda for local return
  • Block variable shadows outer scope — x = 1; [2].each { |x| }; x is still 1 (3.0+)
  • method_missing without respond_to_missing? — breaks respond_to? checks
  • private in Ruby is per-object — self.private_method fails, implicit receiver works
  • ||= doesn't work for false/nil distinction — false ||= true replaces false
  • Frozen string literals — # frozen_string_literal: true makes strings immutable
  • Symbol#to_proc — &:method_name only works with no-argument methods
  • rescue => e without type — catches StandardError, not Exception
  • ensure always runs — even after return, use for cleanup