code-quality

name	code-quality
description	Review and improve code quality across any programming language. Use when conducting code reviews, refactoring for best practices, identifying code smells, or improving maintainability.
license	MIT

Code Quality Reviewer

Expert skill for code quality assessment and improvement.

Quick Check

• No magic numbers (use named constants)
• Functions under 50 lines
• DRY principle followed
• Error handling implemented
• Tests cover edge cases
• No code smells

When to Use

• Code reviews
• Refactoring
• Identifying code smells
• Pre-commit quality checks
• Legacy modernization

Core Principles

DRY

# Bad: Duplicated
def calc_tax_us(p): return p * 0.08
def calc_tax_eu(p): return p * 0.20

# Good: Extract constant
TAX_RATES = {'US': 0.08, 'EU': 0.20}
def calc_tax(p, region): return p * TAX_RATES[region]

Single Responsibility

// Bad: One function does everything
function process(data) { validate(data); save(data); notify(data); }

// Good: Separate concerns
validate(data); save(data); notify(data);

No Magic Numbers

// Bad
if timeout > 30000 { /* ... */ }

// Good
const TIMEOUT_MS: u32 = 30000;
if timeout > TIMEOUT_MS { /* ... */ }

Code Smells

Bloaters

• Long Method (>50 lines)
• Large Class (>300 lines)
• Long Parameter List (>4 params)

Object-Orientation Abusers

• Switch Statements (replace with polymorphism)
• Temporary Field
• Refused Bequest

Dispensables

• Duplicate Code
• Lazy Class
• Dead Code
• Speculative Generality

Couplers

• Feature Envy
• Inappropriate Intimacy
• Message Chains (obj.getX().getY())

Quality Criteria

• No magic numbers
• Functions under 50 lines
• Classes under 300 lines
• DRY followed
• Error handling complete
• Tests cover edge cases
• No code smells

Best Practices

DO:

• Use named constants
• Write small functions
• Handle errors explicitly
• Write edge case tests
• Follow language idioms
• Refactor continuously

DON'T:

• Copy-paste code
• Ignore compiler warnings
• Skip error handling
• Use single-letter names
• Mix abstraction levels
• Return null when possible

Tools by Language

Language	Linter	Formatter	Test
Python	ruff	black	pytest
TypeScript	eslint	prettier	jest
Rust	clippy	rustfmt	cargo test
Go	golangci-lint	gofmt	go test

References

• agents-docs/SKILL.md - Skill authoring guide