Code Quality

Code Quality

Comprehensive code auditing for security, performance, accessibility, complexity, and maintainability.

Quick Start

Security audit:

Perform a security audit on this codebase, checking for OWASP Top 10 vulnerabilities.

Complexity analysis:

Analyze cyclomatic and cognitive complexity across the codebase.

Performance review:

Analyze this code for performance issues like N+1 queries, memory leaks, and blocking calls.

Capabilities

1. Security Audit

OWASP Top 10 Checklist

See references/security-patterns.md for language-specific vulnerability patterns.

Secrets Detection

Patterns to scan for:

# API Keys
(?i)(api[_-]?key|apikey)['":\s]*[=:]\s*['"]?[a-zA-Z0-9_-]{20,}

# AWS
AKIA[0-9A-Z]{16}
(?i)aws[_-]?secret[_-]?access[_-]?key

# Private Keys
-----BEGIN (RSA |EC |OPENSSH )?PRIVATE KEY-----

# Connection Strings
(?i)(mongodb|postgres|mysql|redis):\/\/[^\s'"]+

Injection Analysis

// VULNERABLE - SQL Injection
const query = `SELECT * FROM users WHERE id = ${userId}`;

// SAFE - Parameterized
const query = 'SELECT * FROM users WHERE id = ?';
db.query(query, [userId]);

2. Complexity Analysis

Cyclomatic Complexity

Measures independent paths through code:

# JavaScript/TypeScript
npx escomplex src/ --format json

# Python
radon cc src/ -a -j

# Multi-language
lizard src/ --CCN 15

Cognitive Complexity

Measures mental effort to understand code:

Increment for:

• Nested structures (+nesting level)
• Breaks in linear flow
• Complex conditions

See references/complexity-thresholds.md for language-specific thresholds.

Code Complexity Report

## Complexity Analysis: {module}

### Summary
| Metric | Value | Threshold | Status |
|--------|-------|-----------|--------|
| Avg Cyclomatic | 12.3 | 15 | OK |
| Max Cyclomatic | 45 | 25 | FAIL |
| Avg Cognitive | 8.2 | 15 | OK |

### High-Risk Functions
| Function | File | Cyclomatic | Cognitive |
|----------|------|------------|-----------|
| processOrder | orders.ts:45 | 45 | 52 |
| validateForm | forms.ts:23 | 28 | 31 |

3. Performance Review

N+1 Query Detection

// N+1 PROBLEM
const users = await User.findAll();
for (const user of users) {
  const orders = await Order.findAll({ where: { userId: user.id } });
}

// SOLUTION: Eager loading
const users = await User.findAll({
  include: [{ model: Order }]
});

Memory Leak Patterns

// LEAK: Growing array never cleared
const cache = [];
app.get('/data', (req, res) => {
  cache.push(processData(req));  // Never removed!
});

// LEAK: Event listeners not removed
element.addEventListener('click', handler);
// Missing: removeEventListener

Bundle Size Analysis

# Analyze bundle size
npx webpack-bundle-analyzer stats.json

# Check import costs
npx import-cost src/

# Find large dependencies
npx bundle-phobia-cli lodash

4. Type Coverage Analysis (TypeScript)

# type-coverage tool
npx type-coverage --detail

# Output:
# 85.23% (1234/1448)
# Uncovered locations:
# src/utils.ts:23:5 - any
# src/api.ts:45:12 - unknown

Coverage targets:

Common issues:

• Explicit any usage
• Missing return types
• Implicit any in callbacks
• Untyped third-party libraries

5. API Contract Validation

OpenAPI Compliance

# Validate OpenAPI spec
npx @redocly/cli lint openapi.yaml

# Generate types from spec
npx openapi-typescript openapi.yaml -o types.ts

# Test API against spec
npx dredd openapi.yaml http://localhost:3000

Contract validation checklist:

• All endpoints documented
• Request/response schemas defined
• Error responses specified
• Authentication documented
• Examples provided

Breaking Change Detection

# Compare OpenAPI versions
npx oasdiff breaking old-api.yaml new-api.yaml

# Breaking changes detected:
# - Removed endpoint: DELETE /users/{id}
# - Required parameter added: GET /orders
# - Response property removed: User.email

6. Database Schema Audit

Index usage analysis:

-- PostgreSQL: Find missing indexes
SELECT schemaname, tablename, indexname, idx_scan
FROM pg_stat_user_indexes
WHERE idx_scan = 0;

-- Find slow queries
SELECT query, calls, mean_time
FROM pg_stat_statements
ORDER BY mean_time DESC LIMIT 10;

Normalization issues:

Schema audit checklist:

• Primary keys defined
• Foreign keys with constraints
• Indexes on frequently queried columns
• No duplicate data patterns
• Proper data types used

7. Infrastructure Audit (IaC Security)

Audit Infrastructure as Code for security issues.

Terraform Security

# tfsec - security scanner
tfsec .

# checkov - policy-as-code
checkov -d .

# terrascan
terrascan scan -i terraform

Common Terraform issues:

CloudFormation Security

# cfn-lint
cfn-lint template.yaml

# cfn_nag
cfn_nag_scan --input-path template.yaml

See references/iac-security.md for comprehensive IaC patterns.

8. Accessibility Audit (WCAG)

WCAG 2.1 Level AA Checklist

Perceivable:

• Images have alt text
• Videos have captions
• Sufficient color contrast (4.5:1)

Operable:

• Keyboard accessible
• No keyboard traps
• Focus indicators visible

Understandable:

• Language declared
• Form labels associated
• Error messages descriptive

# axe-core
npx @axe-core/cli https://localhost:3000

# pa11y
npx pa11y https://localhost:3000

# Lighthouse
npx lighthouse https://localhost:3000 --only-categories=accessibility

9. Dead Code Detection

# JavaScript/TypeScript
npx ts-prune
npx unimported

# Python
vulture src/

# Unused dependencies
npx depcheck

Detection Workflow

1. Run static analysis tools
2. Check test coverage for uncovered code
3. Review code not modified in 6+ months
4. Check feature flags for deprecated features

10. Breaking Change Detection

Detect API breaking changes:

# TypeScript API changes
npx api-extractor run --local

# OpenAPI changes
npx oasdiff breaking old.yaml new.yaml

# Package exports
npx publint

Breaking change types:

Audit Report Format

# Code Quality Audit Report

**Project:** {name}
**Date:** {date}

## Executive Summary
- Critical Issues: {count}
- High Severity: {count}
- Medium Severity: {count}

## Security Findings

### CRITICAL: SQL Injection in UserController
**File:** src/controllers/user.js:45
**Impact:** Full database compromise
**Fix:** Use parameterized queries

## Complexity Findings
...

## Performance Findings
...

Hook Integration

PreToolUse Hook - Code Quality Gates

Before commits, validate code quality:

{
  "hooks": {
    "PreToolUse": [{
      "matcher": "Bash",
      "command": "check-quality-gates.sh",
      "condition": "contains(input, 'git commit')"
    }]
  }
}

Gate script example:

#!/bin/bash
# check-quality-gates.sh

# Check complexity
complexity=$(npx escomplex src/ --format json | jq '.aggregate.cyclomatic')
if [ "$complexity" -gt 25 ]; then
  echo "BLOCK: Cyclomatic complexity too high: $complexity"
  exit 1
fi

# Check for secrets
if grep -rE "(api[_-]?key|password)\s*=\s*['\"][^'\"]+['\"]" src/; then
  echo "BLOCK: Potential secrets detected"
  exit 1
fi

# Check TypeScript errors
if ! npx tsc --noEmit; then
  echo "BLOCK: TypeScript errors found"
  exit 1
fi

echo "Quality gates passed"
exit 0

Hook response pattern:

interface QualityGateResponse {
  passed: boolean;
  blockers: Array<{
    type: 'security' | 'complexity' | 'type-error';
    message: string;
    file?: string;
    line?: number;
  }>;
  warnings: string[];
}

PostToolUse Hook - Auto-Audit

After code changes, trigger relevant audits:

• Security scan after file edits
• Complexity check after function changes
• Type coverage after TypeScript changes

CI/CD Integration

GitHub Actions

name: Code Quality
on: [push, pull_request]

jobs:
  quality:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - name: Security Scan
        run: |
          npm audit --audit-level=high
          npx eslint src/ --ext .ts,.js

      - name: Complexity Check
        run: |
          npx escomplex src/ --format json > complexity.json
          node -e "
            const c = require('./complexity.json');
            if (c.aggregate.cyclomatic > 20) {
              console.error('Complexity too high');
              process.exit(1);
            }
          "

      - name: Type Coverage
        run: |
          npx type-coverage --at-least 85

      - name: IaC Security
        if: hashFiles('terraform/**') != ''
        run: |
          tfsec terraform/

Pre-commit Hook

#!/bin/bash
# .git/hooks/pre-commit

# Run linting
npm run lint || exit 1

# Check for secrets
git diff --cached --name-only | xargs grep -l -E "(password|api_key|secret)" && {
  echo "Warning: Possible secrets in staged files"
  exit 1
}

# Type check
npm run type-check || exit 1

Reference Files

• references/security-patterns.md - Language-specific vulnerability patterns
• references/performance-patterns.md - Performance anti-patterns by language
• references/wcag-checklist.md - Complete WCAG 2.1 checklist
• references/complexity-thresholds.md - Complexity thresholds by language
• references/iac-security.md - Infrastructure as Code security patterns

Scripts

• scripts/security_scan.py - Automated security pattern scanning