Add caching

docs/astro.config.ts

@@ -59,4 +59,7 @@ export default defineConfig({
   adapter: node({
     mode: "standalone",
   }),
+  experimental: {
+    session: true,
+  },
 });

packages/starlight-plugin-show-latest-version/components/DynamicVersionBadge.astro

@@ -8,7 +8,7 @@ import { Badge } from '@astrojs/starlight/components';
 	<VersionBadge />
 )}
 {pluginConfig.showInSiteTitle === "deferred" && (
-	<VersionBadge server:defer>
+	<VersionBadge server:defer useCache={true}>
 		<Badge text={"Loading..."} variant="default" size="medium" slot="fallback" />
 	</VersionBadge>
 )}

packages/starlight-plugin-show-latest-version/components/VersionBadge.astro

@@ -1,10 +1,44 @@
 ---
+import type { StarlightPluginShowLatestVersionContext } from '../libs/types';
 import { Badge } from '@astrojs/starlight/components';
 import fetchVersion from '../libs/utils';
 import { releasePageUrls } from "../libs/urlBuilder";
 import pluginConfig from 'virtual:starlight-plugin-show-latest-version-config';
 
-const version = await fetchVersion(pluginConfig);
+interface Props {
+  useCache?: boolean;
+}
+
+const { useCache = false } = Astro.props;
+
+let version: StarlightPluginShowLatestVersionContext = { versionAvailable: false };
+if (useCache) {
+	// This setup caches the result in Astro.session for 1 hour.
+	// Call `clearVersionCache` to manually invalidate the cache. 🚀
+	const CACHE_EXPIRATION_MS = 60 * 60 * 1000;
+
+	const cacheKey = `versionCache:${pluginConfig.source.type}:${pluginConfig.source.slug}`;
+	const cachedData = await Astro.session?.get(cacheKey);
+
+	if (cachedData) {
+		const { timestamp, context } = JSON.parse(cachedData);
+		if (Date.now() - timestamp < CACHE_EXPIRATION_MS) {
+			version = context; 
+		}
+		else {
+			version = await fetchVersion(pluginConfig);
+			await Astro.session?.set(cacheKey, JSON.stringify({ timestamp: Date.now(), context: version }));
+		}
+	}
+	else {
+		version = await fetchVersion(pluginConfig);
+		await Astro.session?.set(cacheKey, JSON.stringify({ timestamp: Date.now(), context: version }));
+	}
+}
+else {
+	version = await fetchVersion(pluginConfig);
+}
+
 const sourceUrl = releasePageUrls[pluginConfig.source.type](pluginConfig.source.slug);
 ---
 

packages/starlight-plugin-show-latest-version/libs/utils.ts

@@ -40,7 +40,7 @@ export default async function fetchVersion(
     const prefix = prefixMatch ? prefixMatch[1] : undefined;
     const hasVPrefix = tagName.startsWith("v") || tagName.includes("@v");
 
-    return {
+    const context: StarlightPluginShowLatestVersionContext = {
       versionAvailable: true,
       version,
       versionWithoutPrefix,
@@ -53,6 +53,8 @@ export default async function fetchVersion(
       hasVPrefix,
       isStableVersion: !isPrereleaseVersion,
     };
+
+    return context;
   } catch (error) {
     console.error(error);
     return { versionAvailable: false }; // Fallback: no version available