Standardizing Express.js Error Handling with One Library

Avatar photoByAdil

If you’ve been working with Express.js for a while, you know the struggle. You start a project, and soon your controllers look like this: 

// The "Bad" Way
app.post('/users', async (req, res) => {
  try {
    // ... logic
  } catch (error) {
    console.error(error);
    if (error.code === 'P2002') { // Prisma unique constraint
        return res.status(400).json({ message: 'User already exists' });
    }
    // ... 10 more if/else checks
    res.status(500).json({ message: 'Something went wrong' });
  }
});

It’s repetitive, hard to maintain, and prone to bugs. I got tired of copy-pasting error handling logic between my projects, so I built a tool to fix it once and for all.

​Meet ds-express-errors.

What is it?

​ds-express-errors is a centralized, type-safe error handling library for Node.js & Express. It aims to replace all your manual try-catch blocks and status code management with a clean, declarative API.
​Here is why I think it’s worth checking out:
​

Ready-to-use Presets 🛠️

​Forget about remembering if “Forbidden” is 401 or 403. Just use the presets. 

import { Errors } from 'ds-express-errors';

if (!user) {
  throw Errors.NotFound('User not found'); // Automatically sends 404
}

if (!user.hasAccess) {
  throw Errors.Forbidden('Access denied'); // Automatically sends 403
}

Auto-Mapping (The Magic 🪄)

​This is my favorite part. If you use Zod, Prisma, or Mongoose, the library automatically detects their native errors and converts them into readable HTTP 400 Bad Requests.

​Example with Zod:
You don’t need to manually parse error.issues.

​Input (Invalid): 

{ "email": "invalid-email" }

Output (Automatic): 

{
  "status": "fail",
  "method": "GET",
  "url": "/login",
  "message": "Validation error: email: Invalid email",
  "stack": // showed when NODE_ENV=development
}

No More try/catch

​
With the included asyncHandler, your controllers become clean again. 

import { asyncHandler, Errors } from 'ds-express-errors';

const createUser = asyncHandler(async (req, res) => {
  const user = await db.create(req.body); // If this throws, it's handled automatically!
  res.json(user);
});

Graceful Shutdown 🛑

​It also handles process-level errors (uncaughtException, unhandledRejection) and allows you to close database connections gracefully before crashing. 

import { initGlobalHandlers } from 'ds-express-errors';

initGlobalHandlers({
  onCrash: () => {
    db.disconnect();
    server.close();
  }
});

📦 How to use it?

​Installation is standard: 

npm install ds-express-errors

📚 Documentation

​
I’ve built a full documentation website where you can see advanced usage, API references, and more examples:

👉ds-express-errors.dev

Conclusion

​Building this library helped me standardize my backend projects, and I hope it helps you too. It’s fully typed (TypeScript), lightweight, and production-ready.
​
Give it a try and let me know what you think! Any feedback or stars on a GitHub are highly appreciated. ❤️

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