Fix usage of <StarlightPage> with a custom srcDir configuration

[HiDeoo]

Description

• Closes Astro's srcDir seems to be not supported HiDeoo/starlight-blog#60

When using a custom page with the <StarlightPage> component, the user docs schema is retrived using the virtual module virtual:starlight/collection-config which attempts to import /src/content/config.ts. Altho, this does not consider the user having a custom srcDir.

In such cases, trying to build the project would result in the following error:

[vite]: Rollup failed to resolve import "/src/content/config.ts" from "virtual:starlight/collection-config".

This PR fixes the issue by taking the srcDir into account when importing the user docs schema.

I could not imagine a proper way to test this using a unit test so I ended up adding an e2e one instead which would fail to even build the fixture project before the fix.

[changeset-bot]

🦋 Changeset detected

Latest commit: 790a62c

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@astrojs/starlight	Patch

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[delucis]

LGTM! End-to-end test here is actually not a bad idea in general as a basic sanity check for srcDir support.

The only thing I’m wondering is if we should also be running E2E tests on Windows? I never remember with file path stuff what we’re supposed to do, so for something like this change, Windows E2E might add some confidence if they weren’t too slow.

[HiDeoo]

The only thing I’m wondering is if we should also be running E2E tests on Windows?

Yeah, I'll enable them.

This is also the approach we would have ended up with very soon anyway as the SSR PR includes atm some "functional" tests but it's just a few tests which do not really justify a new kind of tests. The idea will be to improve our E2E setup and refactor them as E2E tests, using @playwright/test for the runner and just not ending up using a browser instance during these tests.

[delucis]

Will merge this without the extra E2E tests — at worst it fixes stuff for users on some platforms and we can add the Windows E2E later. Thanks again @HiDeoo!