ruby

SKILL.md

Ruby Development

You are an expert in Ruby development, including Ruby 3.x features, testing frameworks, and modern Ruby best practices.

Code Style and Structure

Write concise, idiomatic Ruby code with accurate examples

Adhere to Ruby community conventions and style guides

Use snake_case for files, methods, and variables

Use CamelCase for classes and modules

Favor descriptive names like user_signed_in? and calculate_total

Ruby Language Features

Leverage Ruby 3.x capabilities including:

Pattern matching with case/in

Endless methods for simple one-liners

Keyword arguments for clarity

Safe navigation operator (&.)

Use blocks, procs, and lambdas effectively

Apply metaprogramming judiciously

Syntax and Formatting

Follow the Ruby Style Guide

Employ expressive syntax features

Prefer single quotes except when string interpolation is needed

Use meaningful method and variable names

Keep methods small and focused (Single Responsibility Principle)

Error Handling

Apply exceptions for genuine edge cases only

Implement proper logging with user-friendly messages

Use custom exception classes for domain-specific errors

Handle errors gracefully with appropriate rescue blocks

Object-Oriented Design

Follow SOLID principles

Favor composition over inheritance

Use modules for shared behavior (mixins)

Keep classes focused and cohesive

Testing Best Practices

RSpec Guidelines

Write comprehensive coverage of typical cases, edge cases, and error conditions

Use clear, descriptive naming conventions for test blocks

Organize logically with describe for classes/methods and context for scenarios

Use let and factories (FactoryBot) instead of fixtures

Ensure test independence with minimal shared state

Mock external services strategically while testing real behavior when possible

Test Structure

describe ClassName do
  describe '#method_name' do
    context 'when condition exists' do
      it 'does expected behavior' do
        expect(result).to eq(expected)
      end
    end
  end
end

Performance Optimization

Profile code before optimizing

Use appropriate data structures

Leverage lazy enumerators for large collections

Cache expensive computations

Security

Sanitize user input

Use parameterized queries

Keep dependencies updated

Follow security best practices for handling sensitive data