Dependency Audit Skill

Summary

Systematic workflow for auditing, updating, and cleaning up project dependencies. Covers security vulnerability scanning, outdated package detection, unused dependency removal, and migration from deprecated libraries.

When to Use

• Weekly/monthly dependency maintenance
• After security advisories (CVE announcements)
• Before major releases
• When bundle size increases unexpectedly
• During code reviews for dependency changes
• Onboarding to legacy projects

Quick Audit Process

1. Check Outdated Packages

# npm
npm outdated

# pnpm
pnpm outdated

# yarn
yarn outdated

# pip (Python)
pip list --outdated

# poetry (Python)
poetry show --outdated

2. Security Vulnerability Scan

# npm
npm audit
npm audit fix          # Auto-fix where possible
npm audit fix --force  # Force major version updates (risky)

# pnpm
pnpm audit
pnpm audit --fix

# yarn
yarn audit
yarn audit --fix

# Python
pip-audit              # Requires: pip install pip-audit
safety check           # Requires: pip install safety

3. Find Unused Dependencies

# JavaScript/TypeScript
npx depcheck

# Output example:
# Unused dependencies
# * lodash
# * moment
# Unused devDependencies
# * @types/old-package

# Python
pip-autoremove --list  # Requires: pip install pip-autoremove

---

Audit Commands

JavaScript/TypeScript/Node.js

npm

# Check what's outdated
npm outdated

# Update within semver range (safe)
npm update

# Update specific package to latest
npm install package@latest

# Check security vulnerabilities
npm audit

# Auto-fix vulnerabilities
npm audit fix

# View dependency tree
npm list
npm list --depth=0  # Top-level only

# Why is this package installed?
npm ls package-name

# Check for duplicate packages
npm dedupe

pnpm

# Check outdated
pnpm outdated

# Update all dependencies
pnpm update

# Update specific package
pnpm update package@latest

# Security audit
pnpm audit

# Deduplicate
pnpm dedupe

# List all packages
pnpm list

yarn

# Check outdated
yarn outdated

# Upgrade interactive (recommended)
yarn upgrade-interactive

# Update all
yarn upgrade

# Security audit
yarn audit

# Why is this here?
yarn why package-name

Python

pip

# List outdated
pip list --outdated

# Update specific package
pip install --upgrade package-name

# Security audit
pip-audit  # Install: pip install pip-audit

# Freeze current dependencies
pip freeze > requirements.txt

# Check dependencies of a package
pip show package-name

poetry

# Show outdated
poetry show --outdated

# Update all
poetry update

# Update specific package
poetry update package-name

# Security check
poetry audit  # poetry-audit-plugin required

# Show dependency tree
poetry show --tree

pipenv

# Check for security vulnerabilities
pipenv check

# Update all
pipenv update

# Update specific
pipenv update package-name

# Show dependency graph
pipenv graph

---

Priority Matrix

Priority	Type	Action	Timeline	Example
P0	Critical CVE (actively exploited)	Patch immediately	Same day	Auth bypass, RCE
P1	High CVE or major framework update	Plan migration	1-2 weeks	Next.js, React major version
P2	Deprecated with active usage	Find replacement	2-4 weeks	moment.js → date-fns
P3	Minor/patch updates	Batch update	Monthly	Non-breaking updates
P4	Unused dependencies	Remove	Next cleanup PR	Dead imports

Priority Decision Tree

Is there a CVE?
├─ Yes → Is it critical/high severity?
│  ├─ Yes → P0 (patch immediately)
│  └─ No → P1 (plan update)
└─ No → Is package deprecated?
   ├─ Yes → Is it actively used?
   │  ├─ Yes → P2 (find replacement)
   │  └─ No → P4 (remove)
   └─ No → Is it outdated?
      ├─ Major version → P1 (plan migration)
      ├─ Minor/patch → P3 (batch update)
      └─ Unused → P4 (remove)

---

Common Replacements

Date/Time Libraries

JavaScript/TypeScript

// ❌ moment.js (deprecated, 288KB minified)
import moment from 'moment';
const formatted = moment().format('YYYY-MM-DD');
const diff = moment(date1).diff(moment(date2), 'days');

// ✅ date-fns (tree-shakeable, 2-5KB per function)
import { format, differenceInDays } from 'date-fns';
const formatted = format(new Date(), 'yyyy-MM-dd');
const diff = differenceInDays(date1, date2);

// ✅ Native Intl (zero bundle cost)
const formatted = new Intl.DateTimeFormat('en-US').format(new Date());
const relative = new Intl.RelativeTimeFormat('en').format(-1, 'day'); // "1 day ago"

Python

# ❌ arrow (overhead for simple tasks)
import arrow
now = arrow.now().format('YYYY-MM-DD')

# ✅ Native datetime
from datetime import datetime
now = datetime.now().strftime('%Y-%m-%d')

# ✅ pendulum (for complex timezone handling)
import pendulum
now = pendulum.now('America/New_York')

Utility Libraries

JavaScript/TypeScript

// ❌ Full lodash import (70KB)
import _ from 'lodash';
const value = _.get(obj, 'path.to.value');
const unique = _.uniq(array);

// ✅ Specific imports (5-10KB)
import get from 'lodash/get';
import uniq from 'lodash/uniq';

// ✅ Native alternatives (0KB)
const value = obj?.path?.to?.value;           // Optional chaining
const unique = [...new Set(array)];           // Set
const keys = Object.keys(obj);                // Object.keys
const flat = array.flat();                    // Array.flat()
const grouped = Object.groupBy(arr, fn);      // Object.groupBy

HTTP Clients

JavaScript/TypeScript

// ❌ axios (11KB) - often unnecessary
import axios from 'axios';
const { data } = await axios.get('/api/users');

// ✅ Native fetch (0KB) - built-in
const response = await fetch('/api/users');
const data = await response.json();

// ✅ ky (2KB) - if you need retries/timeout
import ky from 'ky';
const data = await ky.get('/api/users').json();

Python

# ❌ requests (large for serverless)
import requests
response = requests.get('https://api.example.com')

# ✅ httpx (async support, same API)
import httpx
async with httpx.AsyncClient() as client:
    response = await client.get('https://api.example.com')

# ✅ urllib (native, for simple cases)
from urllib.request import urlopen
response = urlopen('https://api.example.com')

Testing Libraries

JavaScript/TypeScript

// Consider consolidating test runners

// If using Jest + Vitest + Playwright separately:
// ✅ Vitest can replace Jest in most projects (faster, native ESM)
// ✅ Keep Playwright for E2E, use Vitest for unit/integration

Validation Libraries

JavaScript/TypeScript

// ❌ Multiple validation libraries
import * as yup from 'yup';
import Joi from 'joi';
import { z } from 'zod';

// ✅ Pick one (Zod recommended for TypeScript)
import { z } from 'zod';
const schema = z.object({
  email: z.string().email(),
  age: z.number().min(0)
});

---

Update Strategy

Batch Related Updates

# Update all ESLint-related packages together
pnpm update eslint @typescript-eslint/parser @typescript-eslint/eslint-plugin

# Update all testing packages together
pnpm update vitest @vitest/ui @vitest/coverage-v8

# Update all Next.js packages together
pnpm update next react react-dom @types/react @types/react-dom

Test After Updates

Comprehensive Testing Checklist

# 1. Type check
pnpm tsc --noEmit

# 2. Lint
pnpm lint

# 3. Unit tests
pnpm test

# 4. Build verification
pnpm build

# 5. Dev server (smoke test)
pnpm dev
# Open browser, test key features

# 6. E2E tests (if available)
pnpm test:e2e

Incremental Update Strategy

For Major Version Updates

# 1. Create branch
git checkout -b chore/update-nextjs-15

# 2. Update package.json
# Change "next": "^14.0.0" → "^15.0.0"

# 3. Install
pnpm install

# 4. Read migration guide
# Visit: nextjs.org/docs/upgrading

# 5. Address breaking changes
# Follow migration guide step-by-step

# 6. Test thoroughly
pnpm test && pnpm build

# 7. Commit and PR
git add .
git commit -m "chore: upgrade Next.js to v15"

---

Cleanup Workflow

Step 1: Identify Unused Dependencies

npx depcheck

Example Output:

Unused dependencies
* lodash
* moment
* old-library

Unused devDependencies
* @types/old-package
* unused-test-lib

Step 2: Verify Not Used

# Search codebase for imports
rg "from 'lodash'" --type ts
rg "import.*lodash" --type ts
rg "require\('lodash'\)" --type js

# If no results → safe to remove

Step 3: Remove Package

pnpm remove lodash

Step 4: Update Lock File

# npm
rm package-lock.json
npm install

# pnpm
rm pnpm-lock.yaml
pnpm install

# yarn
rm yarn.lock
yarn install

Step 5: Test

pnpm test
pnpm build

Cleanup PR Template

## Dependency Cleanup

### Security Updates (P0/P1)
- [ ] `next`: 14.0.4 → 14.2.3 (CVE-2024-XXXX)
- [ ] `jose`: 4.15.4 → 4.15.5 (CVE-2024-YYYY)

### Removed (Unused)
- [ ] `lodash` - replaced with native JS methods
- [ ] `moment` - replaced with date-fns
- [ ] `@types/old-package` - package no longer used

### Updated (Maintenance)
- [ ] `eslint`: 8.57.0 → 9.0.0
- [ ] `typescript`: 5.3.3 → 5.4.2

### Migration Notes
**lodash → Native**:
- `_.get()` → optional chaining `obj?.prop?.value`
- `_.uniq()` → `[...new Set(array)]`

**moment → date-fns**:
- `moment().format('YYYY-MM-DD')` → `format(new Date(), 'yyyy-MM-dd')`

### Testing
- [ ] All tests pass (`pnpm test`)
- [ ] Build succeeds (`pnpm build`)
- [ ] No runtime errors in dev (`pnpm dev`)
- [ ] E2E tests pass (if applicable)

### Bundle Size Impact
- Before: 2.4 MB
- After: 1.8 MB
- **Savings: 600 KB (25% reduction)**

---

Security Scanning

Automated Security Checks

GitHub Actions

# .github/workflows/security.yml
name: Security Audit

on:
  schedule:
    - cron: '0 0 * * 1'  # Weekly on Monday
  pull_request:
  push:
    branches: [main]

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

      - name: Setup Node.js
        uses: actions/setup-node@v4
        with:
          node-version: '20'

      - name: Install dependencies
        run: npm ci

      - name: Run security audit
        run: npm audit --audit-level=high

      - name: Check for outdated packages
        run: npm outdated || true

      - name: Dependency review
        uses: actions/dependency-review-action@v4
        if: github.event_name == 'pull_request'

Snyk Integration

# .github/workflows/snyk.yml
name: Snyk Security

on: [push, pull_request]

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

      - name: Run Snyk to check for vulnerabilities
        uses: snyk/actions/node@master
        env:
          SNYK_TOKEN: ${{ secrets.SNYK_TOKEN }}

Manual Security Commands

# npm security audit
npm audit

# Show only high/critical
npm audit --audit-level=high

# Get JSON report
npm audit --json > audit-report.json

# Snyk (requires: npm install -g snyk)
snyk test                    # Test for vulnerabilities
snyk monitor                 # Continuous monitoring
snyk wizard                  # Interactive fixing

# Socket.dev (supply chain security)
npx socket-npm audit

CVE Response Process

1. Notification: Receive security advisory (GitHub, npm, Snyk)

2. Assess Impact:

   # Find where vulnerable package is used
   npm ls vulnerable-package
   
   # Check if we use vulnerable functionality
   rg "vulnerableFunction" --type ts
   

3. Patch:

   # Update to patched version
   npm install vulnerable-package@4.15.5
   
   # Or update dependency that depends on it
   npm update parent-package
   

4. Verify Fix:

   npm audit
   # Should show 0 vulnerabilities
   

5. Test & Deploy:

   pnpm test && pnpm build
   git commit -m "fix: patch CVE-2024-XXXX in vulnerable-package"
   

---

Summary

Monthly Maintenance Checklist

## Dependency Maintenance - [YYYY-MM]

### Security
- [ ] Run `npm audit` and address high/critical issues
- [ ] Review GitHub security advisories
- [ ] Check Snyk dashboard (if integrated)

### Updates
- [ ] Check `npm outdated` for major updates
- [ ] Update patch versions: `npm update`
- [ ] Plan migration for deprecated packages

### Cleanup
- [ ] Run `npx depcheck` to find unused deps
- [ ] Remove packages with zero imports
- [ ] Deduplicate: `npm dedupe`

### Testing
- [ ] Run full test suite
- [ ] Check build succeeds
- [ ] Verify dev server works
- [ ] Test in production-like environment

### Documentation
- [ ] Update CHANGELOG.md
- [ ] Document breaking changes
- [ ] Update .env.example if needed

Best Practices

• Automate: Set up GitHub Actions for weekly audits
• Batch Updates: Group related dependency updates
• Test Thoroughly: Never skip tests after updates
• Document: Keep CHANGELOG.md updated
• Measure Impact: Track bundle size changes
• Stay Informed: Subscribe to security advisories
• Use Lock Files: Commit package-lock.json/pnpm-lock.yaml
• Gradual Migration: Don't update everything at once