cached-dns

library0.0.4jsnpmunverified

A lightweight DNS caching library for Node.js that wraps the built-in dns.lookup and dns.promises.lookup with a TTL-based cache. Current stable version is 0.0.4, released as a single module with TypeScript types. It provides a drop-in replacement for Node.js DNS resolution with configurable cache size and TTL. Key differentiators: same API as Node's dns module, supports callback and promise variants, optional global patching, and no external dependencies. Release cadence is low; package is minimal and focused.

devops

npm install cached-dns

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INSTALL

IMPORT

SIG · CACHED-DNS

cached-dns

devopsjavascriptv0.0.4

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

lookup

✓ import { lookup } from 'cached-dns'

✗ import lookup from 'cached-dns'

This is a named export, not a default export.

lookupPromise

✓ import { lookupPromise } from 'cached-dns'

Promise-based version of the lookup function.

patchGlobal

✓ import { patchGlobal } from 'cached-dns'

Patches Node's global dns.lookup; use with caution.

CachedDNS Options

✓ import { CacheOptions } from 'cached-dns'

TypeScript type for cache configuration (TTL, max size).

Demonstrates callback lookup, promise lookup, and usage with http.get.

import { lookup, lookupPromise } from 'cached-dns'; import http from 'http'; // Callback style lookup('google.com', { family: 4 }, (err, address, family) => { console.log('IP:', address); }); // Promise style const ip = await lookupPromise('google.com', { family: 4 }); console.log('IP:', ip); // Use custom lookup in http.get http.get({ hostname: 'google.com', path: '/', lookup }, (res) => { console.log('Status:', res.statusCode); });

Debug

Known issues

breakingGlobal patching via patchGlobal() is irreversible and can cause unexpected behavior in tests and production.

fix

Avoid using patchGlobal() for persistent changes; pass lookup function explicitly.

affects: >=0.0.1

deprecatedThe callback API may be deprecated in future versions in favor of async/await.

fix

Use lookupPromise for new projects; callback API is stable but not recommended.

affects: >=0.0.1

gotchaCache is entirely in-memory and does not persist across process restarts; no external cache backend.

fix

Be aware that cache is per-process; consider external caching if persistence is needed.

affects: >=0.0.1

gotchaThe library does not implement standard Node.js DNS error handling (e.g., ENOTFOUND) — errors are direct from dns.lookup.

fix

Wrap calls in try-catch when using promises, or handle errors in callbacks as usual.

affects: >=0.0.1

Errors

Common errors & fixes

Cannot find module 'cached-dns'

Package not installed or not in node_modules.

fix

Run 'npm install cached-dns' in your project root.

lookup is not a function

Wrong import style: trying to use default import instead of named import.

fix

Use `import { lookup } from 'cached-dns'` instead of `import lookup from 'cached-dns'`.

TypeError: Cannot read property 'lookup' of undefined

Assuming cached-dns exports the full dns module object.

fix

Import individual functions: `import { lookup } from 'cached-dns'`.

Upgrade

Version history

0.0.4latest on npm

Audit

Dependencies

No dependency data recorded yet.

Agent activity

2 hits · last 30 days

node

Resources

githubhttps://github.com/jamiees2/cached-dns ↗

packagecached-dns ↗

homepagehttps://github.com/jamiees2/cached-dns ↗