lru-memorise

library0.3.1jsnpmunverified

A simple memoization library wrapping a fast LRU cache (tiny-lru). Current stable version is 0.3.1. It supports memoizing both synchronous and asynchronous functions, automatic cache key generation from function arguments via JSON.stringify, configurable TTL and max cache size, and full TypeScript typings. Unlike other memoize libraries, it exposes the underlying cache for inspection and supports custom cache key resolvers. Suitable for Node.js and browsers.

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npm install lru-memorise

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INSTALL

IMPORT

SIG · LRU-MEMORISE

lru-memorise

productivityjavascriptv0.3.1

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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 memoize from 'lru-memorise';

✗ const memoize = require('lru-memorise');

Package ships ESM and CommonJS, but default export is the preferred usage.

MemoizeOptions

✓ import type { MemoizeOptions } from 'lru-memorise';

✗ import { MemoizeOptions } from 'lru-memorise';

TypeScript users should import types with 'import type' to avoid runtime issues.

Resolver

✓ import type { Resolver } from 'lru-memorise';

✗ import { Resolver } from 'lru-memorise';

The Resolver type is for custom cache key functions; imported as type.

Demonstrates memoization of a sync function with TTL and max cache size.

import memoize from 'lru-memorise'; const expensiveFunction = (a: number, b: number): number => { console.log('computing...'); return a + b; }; const memoized = memoize(expensiveFunction, { lruOptions: { max: 100, ttl: 60000 } // cache max 100 entries, TTL 60 seconds }); console.log(memoized(1, 2)); // computes, logs 'computing...', outputs 3 console.log(memoized(1, 2)); // returns from cache, no log console.log(memoized(3, 4)); // computes, logs 'computing...', outputs 7

Debug

Known issues

gotchaCache key generation uses JSON.stringify on arguments by default, which can produce unexpected keys for non-primitive arguments like objects with circular references or undefined values.

fix

Provide a custom cacheKeyResolver that safely serializes arguments.

affects: >=0.1.0

gotchaWhen memoizing async functions, the cache stores the Promise itself, not the resolved value. This means if the function throws, the rejected promise is cached and subsequent calls will also reject immediately.

fix

Ensure your async function never rejects, or clear the cache on rejection.

affects: >=0.1.0

deprecatedThe `_cache` property on the memoized function is not formally documented and may change between minor versions.

fix

Use the `cache` option with an external LRU cache to have full control.

affects: >=0.1.0

Errors

Common errors & fixes

TypeError: memoize is not a function

Using CommonJS require incorrectly - the default export is not directly available.

fix

Use `const memoize = require('lru-memorise').default;` for CommonJS.

TS2345: Argument of type 'typeof import(...)' is not assignable to parameter of type '(...args: any[]) => any'

Passing a class or non-function to memoize.

fix

Ensure the first argument is a function (async or sync).

Error: options must be an object

Passing a non-object as the second argument to memoize.

fix

Always pass an object (possibly empty) as options: `memoize(fn, {})`.

Upgrade

Version history

0.3.1latest on npm

Audit

Dependencies

tiny-lrurequiredUnderlying LRU cache implementation; used internally when no cache is provided

Agent activity

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Resources

githubhttps://github.com/cajames/lru-memorise ↗

packagelru-memorise ↗

homepagehttps://github.com/cajames/lru-memorise ↗