fix: set statusCode property on error in layer.js to ensure proper error handling

[ale-grosselle]

Description

When using this router with Next.js, which relies on the statusCode property (and not status), errors incorrectly default to a 500 status because Next.js does not read the status property.

In Express 4.x, both status and statusCode were set on error objects. However, in this version, only status is set. This causes compatibility issues with Next.js, resulting in incorrect HTTP status codes being returned.

This fix ensures that the statusCode property is also set on error objects in layer.js, restoring compatibility with Next.js and preventing erroneous 500 responses.

[bjohansebas]

Hi, it’s necessary to add or modify the tests to verify the behavior you want.

Edit: I haven’t reviewed the PR in depth yet, I’ll do it later. But it would be good if you could add tests.

[ale-grosselle]

Hi @bjohansebas, you're right – I'll implement a test for it.

Just to share some context: I was simply reporting how it was implemented in Express 4.x, and with that implementation, there were no unexpected 500 errors when used with Next.js:
https://github.com/expressjs/express/blob/4.21.2/lib/router/layer.js#L176

[ale-grosselle]

Hi @bjohansebas test added

[ale-grosselle]

Hello @bjohansebas any updates?
Thanks, Ale