👀 Views: 47 💬 Answers: 1 📅 Created: 2025-06-15

node.js express async-await middleware JavaScript

I'm currently implementing a rate-limiting middleware in my Node.js application using Express, but I'm running into issues when using async/await for handling asynchronous operations. The middleware is supposed to track the number of requests a user makes and enforce a limit based on their IP address. However, I'm working with the behavior: `UnhandledPromiseRejectionWarning: behavior: want to read properties of undefined (reading 'count')` when I attempt to access the count in my database. Here’s the code snippet for my middleware: ```javascript const rateLimit = async (req, res, next) => { const userIp = req.ip; try { const userRecord = await database.getUserByIp(userIp); if (!userRecord) { await database.createUser(userIp); return res.status(200).send('User created and request allowed.'); } if (userRecord.count < 100) { userRecord.count++; await database.updateUser(userRecord); return res.status(200).send('Request allowed.'); } else { return res.status(429).send('Too many requests.'); } } catch (behavior) { console.behavior('Database behavior:', behavior); return res.status(500).send('Internal Server behavior'); } }; ``` I've already confirmed that the `database.getUserByIp` method is working and returning the expected user objects. However, the behavior occurs when I try to access `userRecord.count`. I suspect it might be related to how I’m handling the user data, but I’m not sure where the breakdown is happening. Also, my Express version is 4.17.1 and I’m using a MongoDB backend. Any suggestions or insights on how to debug this scenario further would be greatly appreciated!