sandi-metz-rules

Sandi Metz's rules enforce class size under 100 lines, methods under 5 lines, parameters under 4, and single object instantiation in controllers. This Skill automatically scans Ruby codebases to identify violations and flag them for refactoring, helping maintain code quality and object-oriented design.

Sandi Metz's rules limit classes to 100 lines, methods to 5 lines, parameters to 4 per method, and controllers to instantiate only one object. These constraints reduce complexity, improve testability, and encourage better object-oriented design in Ruby applications.

This Skill provides concrete refactoring strategies for each violation type: extract sub-methods with descriptive names for long methods, introduce Parameter Objects to reduce parameters, split large classes into focused components, and simplify controller logic. Each suggestion targets the specific rule violation detected.

Yes. This Skill automates code review by identifying Sandi Metz rule violations in Ruby codebases, saving manual review time. It flags violations and suggests targeted refactorings, making it ideal for refactoring sessions and maintainability assessments.

This Skill applies Sandi Metz's rules as a focused maintainability analysis for Ruby projects. It complements existing code quality tools by automating detection of these four specific constraints and providing refactoring guidance aligned with object-oriented design principles.

Violations indicate code complexity that may reduce maintainability and testability. This Skill detects violations and recommends concrete refactorings—such as extracting methods, introducing abstractions, or splitting responsibilities—to bring code into compliance with Sandi Metz's guidelines.