How do I test 404 error handling in Express.js?

How do I test 404 error handling in Express.js?

To test 404 error handling in Express.js, you can create a route that doesn't exist and check the response.

Can you show me a code example?

Sure! You can use the following code:

app.use((req, res, next) => {
  res.status(404).send('Sorry, not found!');
});

This middleware will catch all requests that don't match any defined routes.

How can I automate this test?

You can use testing frameworks like Mocha or Jest along with Supertest to automate your tests for 404 errors.

What should I include in my test cases?

Include assertions to check the status code, response message, and ensure that the middleware is triggered for non-existent routes.