fix: preserve preview docs navigation

2 files changed, 52 insertions, 1 deletions

diff --git a/website/src/components/Sidebar.astro b/website/src/components/Sidebar.astro
new file mode 100644
index 00000000..c875a390
--- /dev/null
+++ b/website/src/components/Sidebar.astro
@@ -0,0 +1,49 @@
+---
+import MobileMenuFooter from 'virtual:starlight/components/MobileMenuFooter';
+import SidebarPersister from '@astrojs/starlight/components/SidebarPersister.astro';
+import SidebarSublist from '@astrojs/starlight/components/SidebarSublist.astro';
+
+const { sidebar } = Astro.locals.starlightRoute;
+const pathname = Astro.url.pathname;
+const isPreview = pathname === '/docs/preview/' || pathname.startsWith('/docs/preview/');
+const channelSidebar = isPreview ? rewriteSidebar(sidebar) : sidebar;
+
+function rewriteSidebar(entries) {
+  return entries.map((entry) => {
+    if (entry.type === 'link') {
+      const href = previewHref(entry.href);
+      return {
+        ...entry,
+        href,
+        isCurrent: samePath(href, pathname),
+      };
+    }
+    const rewrittenEntries = rewriteSidebar(entry.entries);
+    return {
+      ...entry,
+      entries: rewrittenEntries,
+    };
+  });
+}
+
+function previewHref(href) {
+  if (!href.startsWith('/docs/') || href.startsWith('/docs/preview/')) return href;
+  return href === '/docs/' ? '/docs/preview/' : href.replace(/^\/docs\//, '/docs/preview/');
+}
+
+function samePath(left, right) {
+  return stripTrailingSlash(left) === stripTrailingSlash(right);
+}
+
+function stripTrailingSlash(path) {
+  return path.length > 1 ? path.replace(/\/$/, '') : path;
+}
+---
+
+<SidebarPersister>
+  <SidebarSublist sublist={channelSidebar} />
+</SidebarPersister>
+
+<div class="md:sl-hidden">
+  <MobileMenuFooter />
+</div>
diff --git a/website/src/components/SiteTitle.astro b/website/src/components/SiteTitle.astro
index 1173f2b6..d35da5d6 100644
--- a/website/src/components/SiteTitle.astro
+++ b/website/src/components/SiteTitle.astro
@@ -1,5 +1,7 @@
 ---
 const { siteTitle, siteTitleHref } = Astro.locals.starlightRoute;
+const isPreview = Astro.url.pathname === '/docs/preview/' || Astro.url.pathname.startsWith('/docs/preview/');
+const docsHref = isPreview ? '/docs/preview/' : '/docs/';
 ---
 
 <div class="title-row sl-flex">
@@ -8,7 +10,7 @@ const { siteTitle, siteTitleHref } = Astro.locals.starlightRoute;
     <span translate="no">{siteTitle}</span>
   </a>
   <nav class="title-nav" aria-label="Primary">
-    <a href="/docs/">Docs</a>
+    <a href={docsHref}>Docs</a>
     <a href="/releases/">Releases</a>
     <a href="/blog/">Blog</a>
   </nav>