typescript-memoize

import { Memoize, MemoizeExpiring } from 'typescript-memoize'; class DataService { private callCount: number = 0; @Memoize() public getExpensiveData(): string { this.callCount++; console.log(`Fetching expensive data... (call count: ${this.callCount})`); return `Data fetched at ${new Date().toISOString()}`; } @MemoizeExpiring(3000) // Cache expires after 3 seconds public getExpiringData(param: string): string { console.log(`Fetching expiring data for '${param}'...`); return `Expiring data for ${param} at ${new Date().toISOString()}`; } // Custom hash function for memoizing based on multiple parameters @Memoize((id: number, type: string) => `${id}-${type}`) public getItem(id: number, type: string): string { console.log(`Fetching item ${id} of type ${type}...`); return `Item ${id} (${type}) retrieved at ${new Date().toISOString()}`; } } async function runExample() { const service = new DataService(); console.log("--- Standard Memoize ---"); console.log(service.getExpensiveData()); // Fetches console.log(service.getExpensiveData()); // Returns cached console.log(service.getExpensiveData()); // Returns cached console.log("\n--- Expiring Memoize ---"); console.log(service.getExpiringData("A")); // Fetches console.log(service.getExpiringData("A")); // Returns cached await new Promise(resolve => setTimeout(resolve, 3100)); // Wait for cache to expire console.log(service.getExpiringData("A")); // Fetches again after expiration console.log("\n--- Custom Hash Function Memoize ---"); console.log(service.getItem(1, "book")); // Fetches console.log(service.getItem(1, "book")); // Returns cached console.log(service.getItem(2, "book")); // Different key, fetches console.log(service.getItem(1, "movie")); // Different key, fetches } runExample();