code-quality

Code Quality Skills

Overview

Code quality practices for writing clean, maintainable, and reliable code. These skills cover linting, static analysis, refactoring, naming conventions, documentation, and best practices.

Quality Metrics

| Metric | Good | Warning | Bad | |--------|------|---------|-----| | Cyclomatic Complexity | < 10 | 10-20 | > 20 | | Function Length | < 20 lines | 20-50 | > 50 | | File Length | < 300 lines | 300-500 | > 500 | | Nesting Depth | < 3 | 3-4 | > 4 | | Code Coverage | > 80% | 60-80% | < 60% | | Duplicate Code | < 3% | 3-5% | > 5% | | Technical Debt Ratio | < 5% | 5-10% | > 10% |

Categories

Linting

Automated code style enforcement and error detection:

• ESLint - JavaScript/TypeScript linting
• Prettier - Code formatting
• Stylelint - CSS/SCSS linting
• lint-staged - Pre-commit linting

Static Analysis

Deep code analysis beyond linting:

• TypeScript Strict Mode - Maximum type safety
• SonarQube - Comprehensive analysis platform
• Code Coverage - Test coverage metrics

Refactoring

Code improvement techniques:

• Code Smells - Identifying problematic patterns
• Refactoring Techniques - Systematic improvements
• Extract Method - Breaking down functions
• When to Refactor - Decision framework

Naming

Clear and consistent naming:

• Naming Conventions - Project-wide standards
• Variable Naming - Descriptive identifiers
• Function Naming - Action-oriented names

Documentation

In-code documentation:

• Code Comments - When and how to comment
• JSDoc/TSDoc - Type documentation
• README Standards - Project documentation

Practices

Development best practices:

• Clean Code Principles - Foundational concepts
• Code Review Checklist - Review guidelines
• Technical Debt - Managing and reducing debt
• Boy Scout Rule - Continuous improvement

Quality Gates Integration

# .f5/quality/code-quality-gate.yaml
code_quality_gate:
  name: "Code Quality Standards"
  metrics:
    lint_errors: 0
    lint_warnings: 10
    complexity_max: 15
    coverage_min: 80
    duplication_max: 3

  checks:
    - eslint --max-warnings 0
    - tsc --noEmit
    - jest --coverage --coverageThreshold='{"global":{"lines":80}}'

Tool Stack

| Tool | Purpose | Configuration | |------|---------|---------------| | ESLint | Linting | eslint.config.js | | Prettier | Formatting | .prettierrc | | TypeScript | Type checking | tsconfig.json | | Jest | Testing/Coverage | jest.config.js | | Husky | Git hooks | .husky/ | | lint-staged | Pre-commit | package.json |

Quick Setup

# Install core tools
npm install -D eslint prettier typescript @typescript-eslint/parser @typescript-eslint/eslint-plugin

# Install formatting
npm install -D eslint-config-prettier eslint-plugin-prettier

# Install git hooks
npm install -D husky lint-staged
npx husky init

# Configure lint-staged
npm pkg set lint-staged='{"*.{ts,tsx}":["eslint --fix","prettier --write"]}'

Related Skills

• [Testing](/skills/testing/) - Test-driven quality
• [Security](/skills/security/) - Secure coding practices
• [Performance](/skills/performance/) - Performance optimization
• [Architecture](/skills/architecture/) - Structural quality