Better error handling

[florian-lefebvre]

Body

Summary

Document 500.astro and allow retrieving the thrown error in it.

Background & Motivation

Error handling is an important part of an SSR application. Things can go wrong and we don't want to show our users the scary default page of Vercel, Netlify etc.

The 500.astro page had been requested in #610 and even though no answer has been given nor documentation added, this page is in fact supported. But it currently lacks the ability to retrieve the error and handle it properly (show some data, report etc).

Goals

• Document the existence of 500.astro
• Retrieve the thrown error
• Be able to use the 500.astro page in dev to test it properly

Example

We can take example on Nuxt and Next.js.

The error could be provided by props:

---
// src/pages/500.astro
interface Props {
	error: unknown
}

const { error } = Astro.props

Using the 500.astro instead of the dev overlay could be made possible using a flag, for example an environment variable or a new argument for astro dev

[florian-lefebvre]

POC at withastro/astro#11134

[millette]

Were 401, 403, 4xx (400) pages discussed as well? I just tried to add a 403.astro page but it's not being picked up (with node adapter).

[florian-lefebvre]

Nope only 404 and 500 are. However I know there's an integration for it https://github.com/JohannesKlauss/astro-error-pages

[millette]

Merci for the pointer.