Backend Engineering with Node.js

// Cache GET responses in Redis for 60 seconds
import { redis } from './redis.js';

export function cache(ttl = 60) {
  return async (req, res, next) => {
    const key = `cache:${req.originalUrl}`;
    const hit = await redis.get(key);
    if (hit) return res.json(JSON.parse(hit));

    const send = res.json.bind(res);
    res.json = (body) => {
      redis.set(key, JSON.stringify(body), 'EX', ttl);
      return send(body);
    };
    next();
  };
}