How to handle async errors in Node.js?

[sarah_dev]

I’m building a Node.js REST API and struggling with proper error handling in async/await functions. When an async function throws an error inside an Express route handler, the server just crashes instead of returning a proper error response.

Here’s what I have:

app.get('/users/:id', async (req, res) => {
  const user = await User.findById(req.params.id);
  res.json(user);
});

What’s the best practice for handling errors in async Express routes?

[mike_backend]

Great question! The issue is that Express doesn’t natively handle async errors. You need to either wrap your handlers or use a helper.

Option 1: Try-catch wrapper

const asyncHandler = (fn) => (req, res, next) => {
  Promise.resolve(fn(req, res, next)).catch(next);
};

app.get('/users/:id', asyncHandler(async (req, res) => {
  const user = await User.findById(req.params.id);
  if (!user) throw new NotFoundError('User not found');
  res.json(user);
}));

Option 2: express-async-errors package
Just require it at the top of your app:

require('express-async-errors');

Then add a global error handler middleware:

app.use((err, req, res, next) => {
  console.error(err.stack);
  res.status(err.status || 500).json({ error: err.message });
});

I’d recommend Option 2 for simplicity, but Option 1 gives you more control.