How to fix Error: ENAMETOOLONG: name too long, open 'very_very_long_filename_exceeds_max_length' in Node.js

Error: ENAMETOOLONG: name too long, open '/path/to/very_long_filename...'
    at Object.openSync (node:fs:600:3)

const path = require('path');
const filename = 'your_problematic_filename_here';
const byteLength = Buffer.byteLength(filename, 'utf8');
console.log(`Filename: ${filename}`);
console.log(`Byte length: ${byteLength}`);
console.log(`Character length: ${filename.length}`);

const fs = require('fs');
const path = require('path');

function validateFilename(filename, maxBytes = 255) {
  const byteLength = Buffer.byteLength(filename, 'utf8');
  if (byteLength > maxBytes) {
    throw new Error(
      `Filename exceeds maximum length: ${byteLength} bytes (max: ${maxBytes})`
    );
  }
  return filename;
}

// Use it before file operations
const filename = generateFilename(); // your filename generation logic
validateFilename(filename);
fs.writeFileSync(path.join('/some/dir', filename), data);

const crypto = require('crypto');
const path = require('path');

function truncateFilename(filename, maxBytes = 255) {
  const ext = path.extname(filename);
  const basename = path.basename(filename, ext);
  const byteLength = Buffer.byteLength(filename, 'utf8');

  if (byteLength <= maxBytes) {
    return filename;
  }

  // Reserve space for extension and hash
  const hashLength = 8;
  const maxBaseLength = maxBytes - Buffer.byteLength(ext, 'utf8') - hashLength - 1;

  // Truncate basename and add hash of original
  const hash = crypto
    .createHash('md5')
    .update(basename)
    .digest('hex')
    .slice(0, hashLength);

  let truncated = basename;
  while (Buffer.byteLength(truncated, 'utf8') > maxBaseLength) {
    truncated = truncated.slice(0, -1);
  }

  return `${truncated}-${hash}${ext}`;
}

// Example usage
const longFilename = 'very_very_long_filename_that_exceeds_filesystem_limits.json';
const safeFilename = truncateFilename(longFilename);
console.log(safeFilename); // very_very_long_filename_that_exceeds_filesys-a1b2c3d4.json

// BAD: Concatenating multiple long strings
const filename = `${userId}_${timestamp}_${description}_${category}_${tags.join('_')}.json`;

// GOOD: Use hierarchical directories and shorter names
const dir = path.join('data', userId, category);
const filename = `${timestamp}.json`;
fs.mkdirSync(dir, { recursive: true });
fs.writeFileSync(path.join(dir, filename), data);

// GOOD: Use UUIDs or short hashes
const { v4: uuidv4 } = require('uuid');
const filename = `${uuidv4()}.json`;

// GOOD: Store metadata separately from filename
const filename = 'data.json';
const metadata = { userId, description, category, tags };
fs.writeFileSync(path.join(dir, filename), data);
fs.writeFileSync(path.join(dir, 'metadata.json'), JSON.stringify(metadata));

# For npm: Update to latest version (better at flattening dependencies)
npm install -g npm@latest

# For pnpm: Use shamefully-hoist to flatten node_modules
echo "shamefully-hoist=true" >> .npmrc
pnpm install

# For any package manager: Clean and reinstall
rm -rf node_modules package-lock.json
npm install

npm install -g pnpm
pnpm install