code-quality

Files (8)

• CHECKLIST.md
• SKILL.md
• .eslintrc.js · config-templates/
• .husky-pre-commit.sh · config-templates/
• README.md · config-templates/
• github-actions-ci.yml · config-templates/
• jest.config.js · config-templates/
• package.json.scripts · config-templates/

SKILL.md (first lines)

# Skill: Code Quality Standards & Metrics

## Overview

Code quality is the cornerstone of maintainable, secure, and performant software. This skill provides a comprehensive framework for enforcing quality across five dimensions: static analysis, testing, architecture, security, and CI/CD automation.

## 1. Static Code Quality & Standards

### Linting & Style Enforcement

**What**: Enforce language-specific style guides with automated tools
- **JavaScript/TypeScript**: ESLint + Prettier
- **Python**: Pylint + Black + isort
- **Go**: golangci-lint + gofmt
- **Java**: Checkstyle + Spotless

**Why**: Consistent code style reduces cognitive load, prevents merge conflicts, and catches common mistakes early.

**How to Enforce**:
```yaml
# .eslintrc.js or similar
extends: ['recommended', 'prettier']
rules:
  no-console: warn
  no-unused-vars: error
  max-lines: [warn, { max: 300 }]
```

Configure pre-commit hook:
```bash
husky install
npx husky add .husky/pre-commit "npm run lint:fix"
```

### Naming Conventions

**Standard Patterns**:
- **Variables/functions**: camelCase (JavaScript, Python, Java)
- **Classes**: PascalCase
- **Constants**: SCREAMING_SNAKE_CASE
- **Files**: lowercase with hyphens (components) or snake_case (modules)
- **Avoid**: Single-letter vars (except loop counters), cryptic abbreviations, `data`, `temp`, `info`, `obj`

**Example Violations**:
```javascript
// ❌ Bad
const d = new Date();
const temp = calculateTotal(items);
function x() { return 42; }

// ✓ Good
const currentDate = new Date();
const cartTotal = calculateTotal(items);
function getUserAge() { return 42; }
```

### Complexity Control

**Cyclomatic Complexity Limits**:
- Functions: max 10 branches (if/else, loops, switches)
- Classes: max 50 methods
- Files: max 300 lines

**Tools**: SonarQube, eslint-plugin-complexity, radon (Python)

**How to Measure**:
```bash
# JavaScript
npx eslint --max-warnings 0 --ext .js,.ts src/

# Python
radon cc -n C your_code.py  # Show functions with complexity > C
```

### DRY Principle (Don't Repeat Yourself)

**Red Flags**:
- Copy-pasted code blocks (3+ identical/similar lines)
- Duplicated business logic across files
- Similar patterns in schema definitions

**How to Detect**:
```bash
# Find duplicated code blocks
npx jscpd --threshold 0.1 src/

# Clone detection with git
git diff --stat HEAD~10
```

**Refactoring Patterns**:
- Extract repeated logic into utility functions
- Use mixins, inheritance, or composition for shared behavior
- Consolidate config duplicates into a single source of truth

## 2. Testing & Coverage Rules

### Testing Pyramid

```
          ▲
         /E2E\        10% (expensive, slow)
        /─────\       1-2 tests per critical flow
       /Integration\  20% (medium cost)
      /─────────────\ 10-20 tests per service
     /Unit Tests─────\70% (cheap, fast)
    /─────────────────\Hundreds of tests
```

**Unit Tests** (70%):
- Isolated logic, mocked dependencies
- Run in <100ms
- Fast feedback loop
- Test error cases, boundary conditions

**Integration Tests** (20%):
- Real database/external dependencies
- Run in <1s per test
- Validate module interactions

From saitarrun/Devforge-ai, Apache-2.0.

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