Manually defined sidebars on custom pages do not work with the plugin

[APickledWalrus]

Describe the bug

Perhaps I have something configured incorrectly, but when using the plugin, the sidebar property of custom pages (StarlightPage component) no longer works. The sidebar is just empty.

To Reproduce

Create a custom page with a sidebar. I was able to reproduce using this example:

---
import StarlightPage from '@astrojs/starlight/components/StarlightPage.astro';
---

<StarlightPage
        frontmatter={{ title: 'test page'}}
        sidebar={[
            {
                label: 'Test Page',
                link: '/test',
            }
        ]}
/>

Without the plugin active, it generates as follows:

When the plugin is enabled, the sidebar is no longer present:

Expected behavior

Custom page appearance should be consistent regardless of whether the plugin is enabled (see screenshots above).

How often does this bug happen?

Every time

System Info

OS: macOS 15.7.2
Browsers:

• Microsoft Edge Version 143.0.3650.96 (Official build) (arm64)
• Safari Version 26.1 (20622.2.11.119.1)

Additional Context

Please let me know if there is anything else I can provide. Thanks for your time!

EDIT: To clarify, I am not expecting this plugin to work for custom pages, just the regular pages within the content/docs directory. Ideally, custom pages would just be skipped.

[HiDeoo]

Thanks for the report 🙌

This is definitely a use-case that I forgot to test when creating the plugin. Unfortunately, this is not something I will be able to fix right now as the plugin currently need to heavily rely on the Starlight configuration to identify autogenerated groups. When processing sidebar, the plugin is currently blind when it comes to knowing what is autogenerated or not, if it's a custom page or not, and if it is, if it's using a custom sidebar or not.

The good news is that I have already started an upstream refactor of autogenerated sidebar groups in Starlight that will totally change how this plugin is working and avoid such dependancy on the Starlight configuration.

EDIT: To clarify, I am not expecting this plugin to work for custom pages, just the regular pages within the content/docs directory. Ideally, custom pages would just be skipped.

Actually, once the upstream changes are merged and released, custom sidebar in custom pages using the <StarlightPage> component will also be supported by the plugin.

[APickledWalrus]

Thank you so much for your reply and the clarity! I look forward to the upstream refactor 🙂