coding-ruby

Purpose

This skill allows the AI to generate, debug, and optimize Ruby 3.x code, focusing on advanced constructs like blocks, procs, lambdas, metaprogramming, modules, gem management with Bundler, Rails web apps, and RSpec testing.

When to Use

Use this skill for tasks involving Ruby scripting, such as building web applications with Rails, managing dependencies via Bundler, writing unit tests with RSpec, or applying metaprogramming for dynamic code generation. Apply it when users request code for e-commerce sites, API backends, or custom gems.

Key Capabilities

Handle blocks and procs: Define and yield blocks in methods, e.g., for iterators.
Implement metaprogramming: Use define_method or method_missing for dynamic class creation.
Manage modules: Create and include modules for namespacing, like module MyModule; end.
Work with Bundler: Install and manage gems via Gemfiles for dependency resolution.
Build Rails apps: Generate models, controllers, and routes for MVC architecture.
Write RSpec tests: Create specs for behavior-driven development, including matchers and mocks.

Usage Patterns

To accomplish tasks, structure code with Ruby's idioms: use procs for callbacks, modules for reusable code, and metaprogramming for automation. For Rails, follow the MVC pattern; for RSpec, use describe/it blocks. Always check Ruby 3.x syntax, like pattern matching with case statements. To define a lambda: my_lambda = ->(x) { x * 2 }. Invoke it as my_lambda.call(5). For metaprogramming, add methods dynamically: class MyClass; define_method(:greet) { puts 'Hello' }; end. Integrate Bundler by running bundle install after editing Gemfiles.

Common Commands/API

Use these exact commands for Ruby tasks:

Ruby CLI: Run ruby -v to verify version (e.g., 3.2.2), or start IRB with irb for interactive testing.
Bundler: Execute bundle install --path vendor/bundle to install gems from a Gemfile; update with bundle update gem_name.
Gems: Add a gem via Gemfile: gem 'rspec', '~> 3.12'; then run bundle install.
Rails: Generate a new app with rails new my_app --database=postgresql; create a controller: rails generate controller Users index.
RSpec: Run tests with rspec spec/, or a specific file: rspec spec/models/user_spec.rb --format documentation.
API endpoints in Rails: Define routes in config/routes.rb, e.g., resources :users; access via /users in code. Config formats: Use YAML for Rails configs, e.g., in config/database.yml: default: &default adapter: postgresql username: user. For authentication in gems, set env vars like $RAILS_MASTER_KEY for encrypted credentials.

Integration Notes

Integrate this skill by setting up a Ruby environment first: Install Ruby 3.x via rbenv with rbenv install 3.2.2 and set it globally with rbenv global 3.2.2. For Rails, add to Gemfile and run bundle exec rails server to start on port 3000. Use Bundler for gem isolation: Create a new gem set with bundle init and require gems in code like require 'rspec'. If external APIs are involved (e.g., via gems), handle auth with env vars: Set $GEM_API_KEY and access it in code as ENV['GEM_API_KEY']. For database integration, configure ActiveRecord in Rails models, e.g., class User < ApplicationRecord; end, and migrate with rails db:migrate.

Error Handling

Handle Ruby errors prescriptively: Use begin/rescue blocks for exceptions, e.g.:

begin
  File.open('nonexistent.txt')
rescue Errno::ENOENT => e
  puts "File not found: #{e.message}"
end

For Rails, check logs in log/development.log and use rescue_from in controllers for custom errors. In RSpec, expect errors with expect { code }.to raise_error(SomeError). Common issues: Gem conflicts—resolve with bundle clean --force; syntax errors in Ruby 3.x—use ruby -c file.rb to check. For metaprogramming, catch NoMethodError with method_missing to define fallback behavior.

Graph Relationships

Related to: coding-python (shares metaprogramming concepts), coding-javascript (both use modules and callbacks).
Clusters: Linked to "coding" cluster for general programming skills; connects to "web-development" via Rails integration.
Dependencies: Requires "environment-setup" for Ruby installation; extends "testing-frameworks" through RSpec.