Add displayName to error page(s)

[isaachinman]

Feature request

Is your feature request related to a problem? Please describe.

Recently in next-i18next, we implemented some console warnings to improve DX. If a page-level component does not return namespacesRequired in pageProps, we pass a warning and print that component's displayName to be helpful. This caused me to realise that the _error.js page does not have a displayName.

Describe the solution you'd like

Add a sensible displayName to the _error.js page so that tools built on top of NextJs can make sense of what it is.

I am happy to quickly submit a PR for this and hopefully see it merged and released ASAP! If there is good reason for _error.js to not have a displayName, please do let me know - I searched through the issues and found nothing.

[timneutkens]

Sounds good to me 🤔

[isaachinman]

@timneutkens Cool, any preference on what that should be?

[timneutkens]

I guess Error or ErrorPage 🤔

[isaachinman]

@timneutkens Forgive me if I'm being naïve but is it as simple as #6029? There isn't any documentation on displayName, and surprisingly few examples to go on.

Also, I tried to run testonly locally and hundreds of not-headless Chromium apps were opened simultaneously and crashed my machine. Did I miss something, or would you take a PR for that, too?

The tests seem to be failing on CI but it looks like a registry thing.

[timneutkens]

Looks fine to me!