Debugging File Write Issues with Express and Multer - Unique Error in Code Review
I need some guidance on I've been banging my head against this for hours. I've been working on this all day and This might be a silly question, but I'm stuck on something that should probably be simple. Currently developing a file upload feature for a Node.js application using Express and Multer. During code review, a peculiar issue arose where uploaded files appear to be missing intermittently. The setup looks like this: ```javascript const express = require('express'); const multer = require('multer'); const path = require('path'); const app = express(); const upload = multer({ dest: 'uploads/', limits: { fileSize: 5 * 1024 * 1024 }, // 5 MB limit }); app.post('/upload', upload.single('file'), (req, res) => { if (!req.file) { return res.status(400).send('No file uploaded.'); } res.send(`File uploaded: ${req.file.filename}`); }); app.listen(3000, () => { console.log('Server running on http://localhost:3000'); }); ``` While testing, I noticed that files larger than 3 MB consistently fail to upload, while smaller ones succeed. After diving into the code, I considered the following potential culprits: 1. **Multer configuration:** The limits option is set, but could there be an issue with the `dest` directory permissions? 2. **Error handling:** The callback isn't providing detailed error messages, making it tricky to diagnose issues. 3. **Client-side:** Is the form submission correct, and is it correctly set to `enctype="multipart/form-data"`? I tried adding a simple error-handling middleware to catch any errors from Multer: ```javascript app.use((err, req, res, next) => { if (err instanceof multer.MulterError) { return res.status(500).json({ error: err.message }); } next(err); }); ``` However, even with the additional logging, the logs only show a generic server error without specifying the underlying issue. Also, I’ve checked the server's write permissions for the `uploads` directory, which appear to be fine. Looking for advice on how to better debug this file upload issue or any common pitfalls I might have missed. Any suggestions for diagnosing this problem further would be greatly appreciated! Is there a better approach? Thanks in advance! For reference, this is a production CLI tool. I'm working with Javascript in a Docker container on Windows 11. Thanks, I really appreciate it! This is my first time working with Javascript 3.10. Any advice would be much appreciated.