What is Unusual Cache?

Is a lightweight, pluggable caching middleware for express.js that brings fine-grained response caching with customizable TTL, key generation, and optional external storage backends.

Instalation

npm install unusual-cache

or using yarn:

yarn add unusual-cache

Usage

| Property | Type | Default | Description | | -------------- | ------------------- | --------------------------- | ------------------------------------------- | | ttl | number | 60 (seconds) | Time to live for cache entries | | keyGenerator | (req) => string | (req) => req.originalUrl | Function to generate cache key from request| | store | CacheStore | Map() | Custom cache store implementing .get() and .set() |

import express from 'express';
import cache from 'unusual-cache';

const app = express();

const slowFunction = async () => {
  console.log('⏳ slowFunction called...');
  await new Promise((resolve) => setTimeout(resolve, 3000));
  return { message: '✅ Response from slowFunction' };
};

app.get('/api/data', cache({
  ttl: (req) => req.query.noCache ? 0 : 30,
  keyGenerator: (req) => req.originalUrl.split('?')[0],
}), async (req, res) => {
  const data = await slowFunction();
  res.json(data);
});


app.listen(3000, () => {
  console.log('🚀 Server running on http://localhost:3000');
});