How can I effectively test error handling in Node.js applications?

How can I effectively test error handling in Node.js applications?

You can use tools like Mocha and Chai for unit testing, along with Sinon for mocking. Would you like a code example?

Yes, please provide a code example for testing error handling.

Sure! Here's a simple example:

const { expect } = require('chai');
const sinon = require('sinon');
const myFunction = require('./myFunction');

describe('myFunction', () => {
    it('should handle errors correctly', async () => {
        const error = new Error('Test error');
        const stub = sinon.stub().throws(error);
        try {
            await stub();
        } catch (err) {
            expect(err).to.equal(error);
        }
    });
});

What are some common mistakes to avoid when testing error handling?

Common mistakes include not testing all possible error scenarios, ignoring asynchronous errors, and failing to clean up mocks after tests.