Node.js Package Management

Manage Node.js dependencies using the appropriate package manager CLI. This skill detects which package manager is in use and provides the correct commands.

Golden Rule

Always use the package manager CLI to manage dependencies. Never manually edit package.json or lock files.

Why CLI commands are required:

• Validation: Checks package exists on registry before adding
• Dependency resolution: Correctly handles transitive dependencies
• Lock file integrity: Maintains proper checksums and dependency trees
• Deduplication: Automatically optimizes dependency structure
• Security: Updates lock files with security metadata

Manual editing bypasses these protections and causes broken installs, security gaps, and version conflicts.

Detect Package Manager

Check for lock files in this order:

# Detection script
if [ -f "bun.lockb" ]; then
    echo "bun"
elif [ -f "pnpm-lock.yaml" ]; then
    echo "pnpm"
elif [ -f "yarn.lock" ]; then
    echo "yarn"
elif [ -f "package-lock.json" ]; then
    echo "npm"
else
    echo "none (default to npm)"
fi

Also check for configuration files:

• .npmrc → npm configuration
• pnpm-workspace.yaml → pnpm workspaces
• yarn.lock + .yarnrc.yml → Yarn 2+ (Berry)
• bunfig.toml → Bun configuration

Version managers:

• .nvmrc → Node version for nvm
• .node-version → Node version for fnm/asdf
• engines field in package.json → Required Node version

Quick Command Reference

For detailed commands and options, see:

• npm: references/npm.md
• pnpm: references/pnpm.md
• yarn: references/yarn.md
• bun: references/bun.md

Workspaces

For monorepo setups, each package manager has workspace support:

• npm workspaces: references/workspaces.md#npm-workspaces
• pnpm workspaces: references/workspaces.md#pnpm-workspaces
• yarn workspaces: references/workspaces.md#yarn-workspaces

Complete workspace guide: references/workspaces.md

Security

Check for vulnerabilities:

# Use the appropriate command for your package manager
npm audit
pnpm audit
yarn audit

Fix vulnerabilities:

npm audit fix
pnpm update <package> --latest
yarn upgrade-interactive

CI/CD integration:

# Fail CI if high/critical vulnerabilities found
npm audit --audit-level=high
pnpm audit --audit-level=high

For detailed security practices: references/security.md

Version Management

Semantic versioning in package.json:

• "1.2.3" → Exact version (most strict)
• "^1.2.3" → Compatible (1.x.x, allows minor/patch)
• "~1.2.3" → Patch only (1.2.x)
• "*" → Latest (❌ dangerous, avoid)

Check outdated packages:

npm outdated
pnpm outdated
yarn outdated

Lock exact versions:

npm install --save-exact <package>
pnpm add --save-exact <package>
yarn add --exact <package>

For update strategies and version ranges: references/security.md#version-management

Common Issues

"Cannot find module" after install:

rm -rf node_modules package-lock.json
npm cache clean --force
npm install

Peer dependency conflicts:

# npm - use legacy resolver
npm install --legacy-peer-deps

# pnpm - see which package needs which peer
pnpm why <package>

Lock file corruption:

# Delete and regenerate
rm package-lock.json  # or pnpm-lock.yaml, yarn.lock, bun.lockb
npm install           # or pnpm/yarn/bun install

For complete troubleshooting: references/troubleshooting.md

Anti-Patterns to Avoid

❌ Manual Editing

Never:

• Edit package.json dependencies by hand
• Edit lock files directly
• Copy-paste lock files between projects

Why it breaks:

• Checksums become invalid
• Dependency resolution fails
• Transitive dependencies missing

❌ Mixing Package Managers

Never mix in same project:

• Pick one: npm, pnpm, yarn, or bun
• Add only one lock file to git
• Detect mixing: ls -la *.lock* 2>/dev/null | wc -l (should be 1)

❌ Using sudo with npm

# ❌ Bad - corrupts permissions
sudo npm install -g typescript

# ✓ Good - use nvm or fnm
nvm install 20
npm install -g typescript

❌ Committing node_modules

Never commit to git:

# Add to .gitignore
node_modules/

Lock files provide reproducibility without committing 100s of MB.

❌ Wildcard Versions

// ❌ Bad - unpredictable builds
{ "dependencies": { "lodash": "*" } }

// ✓ Good - explicit version
{ "dependencies": { "lodash": "4.17.21" } }

For all anti-patterns: See package manager guides and references/troubleshooting.md

Migration Between Managers

npm → pnpm:

npm install -g pnpm
pnpm import  # imports from package-lock.json

npm → yarn:

npm install -g yarn
yarn install  # reads package.json
rm package-lock.json

yarn → pnpm:

npm install -g pnpm
rm yarn.lock
pnpm install

For detailed migration steps: references/troubleshooting.md#migration

References

Package manager guides:

• npm Commands - npm-specific commands, flags, and features
• pnpm Commands - pnpm-specific commands, efficiency features
• yarn Commands - Yarn 1.x and Yarn 2+ (Berry) commands
• bun Commands - Bun-specific commands and features

Advanced topics:

• Workspaces - Monorepo management with workspaces
• Security - Vulnerability scanning, lock files, version management
• Troubleshooting - Common issues, debugging, migrations

External documentation:

• npm documentation
• pnpm documentation
• Yarn documentation
• Bun documentation