Redis Cache Middleware Example

I thought I’d share my middleware for using ioredis as a cache simply.

async function cacheMiddleware(req, res, next) {
    const key = `__api__${req.originalUrl || req.url}`;

    try {
        const cachedBody = await redis.get(key);
        if (cachedBody) return res.send(cachedBody);

        // Overwrite res.json to cache the response
        res.json = async (body) => {
            const formattedBody = JSON.stringify(body, null, 4);
            await redis.set(key, formattedBody, 'EX', 60 * 60); // Cache for 1 hour
            res.send(formattedBody);
        };

        next();
    } catch (error) {
        console.error('Redis error:', error);
        next(error);
    }
}

Then all you have to do for your routes is:

app.get('/api/stats/:steamId', cacheMiddleware, async (req, res) => {
	// Other things here.
});

Easy to reuse. Remember, use ioredis. It has built in promises.