$page.error not typed as HttpError

[austins]

Describe the bug

In SvelteKit 1.0.0-next.415, $page.error isn't typed as HttpError (which is not exported publicly).

Reproduction

If you try to output $page.error.message in +error.svelte you'll get an Unsafe member access .message on an any value. eslint(@typescript-eslint/no-unsafe-member-access) error.

<script lang="ts">
    import { page } from "$app/stores";
</script>

<h1>{$page.status}: {$page.error.message}</h1>

Logs

No response

System Info

System:
    OS: Windows 10 10.0.22000
    CPU: (24) x64 AMD Ryzen 9 3900X 12-Core Processor
    Memory: 2.33 GB / 15.93 GB
  Binaries:
    Node: 16.16.0 - ~\scoop\apps\nodejs-lts\current\node.EXE
    npm: 8.15.1 - ~\scoop\apps\nodejs-lts\current\bin\npm.CMD
  Browsers:
    Edge: Spartan (44.22000.120.0), Chromium (104.0.1293.47)
    Internet Explorer: 11.0.22000.120
  npmPackages:
    @sveltejs/adapter-node: ^1.0.0-next.86 => 1.0.0-next.86
    @sveltejs/kit: ^1.0.0-next.415 => 1.0.0-next.415
    @sveltejs/vite-plugin-svelte: ^1.0.1 => 1.0.1
    svelte: ^3.49.0 => 3.49.0
    vite: ^3.0.8 => 3.0.8

Severity

annoyance

Additional Information

No response

[dummdidumm]

This is correct, because this can be something else than HttpError, too (an Error for example, though that one has message, too). Not sure if we can do something here to appease the common case where message exists.

[austins]

For now, we can cast the type like so:

    $: error = $page.error as Error;

[Rich-Harris]

Since errors have to be converted to POJOs to cross the serialization boundary between server and client, their type is really something like

{ status: number, message: string } |
{ name: string, message: string, [key: string]: any }

I feel like we could probably make this work?

[dummdidumm]

Closed via #6586