SOLID Principles for Ruby

Apply the five SOLID principles as practical tools for writing, reviewing, and refactoring Ruby code. Each principle includes detection heuristics, Ruby-idiomatic solutions, and concrete examples.

When to Use

• Designing new classes or modules
• Reviewing code for architectural quality
• Refactoring classes that have grown unwieldy
• Evaluating whether a dependency can be swapped safely
• Deciding where to place new behavior in an existing codebase

The Five Principles — Quick Reference