p-async-cache

library1.0.3jsnpmunverified

Promise-based async cache that deduplicates concurrent lookups by caching the promise itself rather than the resolved value. Version 1.0.3 is stable with no recent updates (last published 2017). It wraps lru-cache to provide a simple API for caching async operations, including stale value support and automatic background refresh. Key differentiators: lightweight, no dependencies beyond lru-cache, and supports sync/async load functions.

storage

npm install p-async-cache

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · P-ASYNC-CACHE

p-async-cache

storagejavascriptv1.0.3

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.

default

✓ import PAC from 'p-async-cache'

✗ import { PAC } from 'p-async-cache'

Default export only; named import will not work.

PAC

✓ const PAC = require('p-async-cache').default

✗ const PAC = require('p-async-cache')

CommonJS require must access .default because package uses ES modules.

PAC

✓ import PAC from 'p-async-cache'

✗ import * as PAC from 'p-async-cache'

Namespace import gives an object with a default property; direct usage fails.

Creates a PAC instance with an async load function, gets the same key twice, and shows counter remains 1 on second call.

import PAC from 'p-async-cache'; let counter = 0; const cache = new PAC({ async load(userId) { counter++; // Simulate async fetch return { id: userId, name: `User${userId}` }; } }); async function main() { const result1 = await cache.get(123); console.log(result1.value); // { id: 123, name: 'User123' } console.log(counter); // 1 const result2 = await cache.get(123); console.log(result2.value); // Same as above console.log(counter); // 1 (load not called again) } main();

Debug

Known issues

gotchaThe default export must be used; named imports like `import { PAC }` result in `undefined` because the package exports only a default.

fix

Use `import PAC from 'p-async-cache'`.

affects: >=1.0.0

gotchaCommonJS `require('p-async-cache')` returns an object with `default` property; you must use `.default` to get the constructor.

fix

Use `const PAC = require('p-async-cache').default`.

affects: >=1.0.0

deprecatedPackage relies on `lru-cache` v4 which has breaking changes in v5+. If you have a newer lru-cache version in your project, it may cause compatibility issues.

fix

Pin `lru-cache` to version 4.x in your dependencies.

affects: >=1.0.0

gotchaThe `get` method resolves to an object `{value, stale}`. Forgetting to destructure `.value` can lead to printing the whole object.

fix

Use `await cache.get(key)` and access `.value`.

affects: >=1.0.0

Errors

Common errors & fixes

TypeError: PAC is not a constructor

Using named import `{ PAC }` or CommonJS without `.default`

fix

Use `import PAC from 'p-async-cache'` or `const PAC = require('p-async-cache').default`

Cannot find module 'p-async-cache'

Package not installed or missing dependency

fix

Run `npm install p-async-cache`

TypeError: cache.get(...).then is not a function

Forget to await the promise returned by `get`

fix

Add `await` before `cache.get(params)`

Upgrade

Version history

1.0.3latest on npm

Audit

Dependencies

lru-cacherequiredruntime dependency for cache storage

Agent activity

16 hits · last 30 days

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OpenAI (training)

Resources

githubgit://github.com/kaelzhang/p-async-cache ↗

packagep-async-cache ↗

homepagehttps://github.com/kaelzhang/p-async-cache#readme ↗