kent-beck-style

Kent Beck Style Coding Review Skill

Overview

This skill analyzes and reviews code based on Kent Beck's refactoring philosophy and simple design principles. It focuses on code smells detection, refactoring techniques, and incremental design improvement.

"Any fool can write code that a computer can understand. Good programmers write code that humans can understand." - Martin Fowler (Refactoring, foreword by Kent Beck)

When to Use

• When user requests "code smell" detection or "refactoring" guidance
• When asked about "code quality", "readability", or "maintainability"
• When reviewing code for improvement opportunities
• When asked about "YAGNI", "KISS", or "simple design"
• When improving naming, extracting methods, or removing duplication

Core Design Principles

Simple Design (4 Rules of Simple Design)

Kent Beck's rules in priority order:

1. Passes the Tests - Code must work correctly
2. Reveals Intent - Code should clearly express its purpose
3. No Duplication - DRY (Don't Repeat Yourself)
4. Fewest Elements - Minimize classes, methods, and code

YAGNI (You Aren't Gonna Need It)

• Don't add functionality until it's actually needed
• Avoid speculative generality
• Build for today's requirements, not imagined futures

// Bad: Speculative generality
interface DataProcessor<T, U, V> {
  process(input: T, options: U): V;
  processAsync(input: T, options: U): Promise<V>;
  processBatch(inputs: T[], options: U): V[];
  // We only need one sync method right now!
}

// Good: Build what you need
interface DataProcessor {
  process(input: string): Result;
}

KISS (Keep It Simple, Stupid)

• Prefer simple solutions over clever ones
• Complexity is the enemy of maintainability
• If it's hard to explain, it's probably too complex

Incremental Design

• Make small, safe changes
• Refactor continuously as you code
• Design emerges through refactoring

Code Smells Catalog

1. Bloaters

Code that has grown too large to handle.