upgrading-ethereum-book/src/components/Subsections.astro

---
import PageList from './PageList.astro';
import '../css/subsections.css';

const { indexArray, pages } = Astro.props;

let index = indexArray;

// Only add the auto index for Parts, not any deeper structure
if (index === undefined || index === null || index.length > 1) return null;

// Special hacky handling for the the /contents page
if (index[0] === -1) {
  index = [];
}

// Find pages that are subsections of the page we are on
const indexFilterString = index.length === 0 ? '' : index.join() + ',';
const filteredPages = pages.filter(p => p.data.index.join().startsWith(indexFilterString))
---

{filteredPages.length > 0
 ? <div class="subsection-list">
     <PageList pages={filteredPages} depth={index.length} />
   </div>
 : null
}