oldStorage

localStorage with automatic expiration. Set key-value pairs with a time-to-live, get them back or null if expired.

Installation

npm install oldstorage

Usage

const { expireIn, isExpired, HOUR, DAY } = require('oldstorage');

// Store a value that expires in 1 hour
expireIn('authToken', 'abc123', HOUR);

// Get the value (returns null if expired)
const token = isExpired('authToken');
console.log(token); // 'abc123' or null if expired

API

expireIn(key, value, ttl)

Store a value in localStorage with an expiration time.

• key - Storage key (string)
• value - Value to store (any JSON-serializable value)
• expirationtime - Time to live in milliseconds (number)

expireIn('user', { name: 'John' }, HOUR);

isExpired(key)

Retrieve a value from localStorage. Returns null if the item doesn't exist or has expired.

• key - Storage key (string)
• Returns: The stored value or null

const user = isExpired('user');

Time Constants

Pre-defined constants for common durations:

MINUTE  // 60000ms (1 minute)
HOUR    // 3600000ms (1 hour)
HOUR2   // 7200000ms (2 hours)
HOUR3   // 10800000ms (3 hours)
// ... up to HOUR23
DAY     // 86400000ms (24 hours)

Usage

const { expireIn, MINUTE, HOUR5, DAY } = require('oldstorage');

expireIn('quickCache', data, MINUTE);      // Expires in 1 minute
expireIn('sessionData', data, HOUR5);      // Expires in 5 hours
expireIn('userPrefs', data, DAY);          // Expires in 1 day
expireIn('custom', data, 5000);            // Expires in 5 seconds (custom ms)

Use Cases

• API response caching - Cache API responses for a few minutes
• Authentication tokens - Store JWT tokens that auto-expire
• Form data - Temporarily save form progress
• Feature flags - Cache remote config with TTL
• User preferences - Store settings that refresh daily
• Rate limiting - Track user actions with expiration

Example

const { expireIn, isExpired, HOUR } = require('oldstorage');

// Store API response
async function fetchUserData(userId) {
  const cached = isExpired(`user-${userId}`);
  if (cached) return cached;
  
  const data = await api.getUser(userId);
  expireIn(`user-${userId}`, data, HOUR);
  return data;
}

License

MIT