Fix remark last modified metadata handling

src/pages/[...slug].astro

@@ -1,35 +1,42 @@
 ---
-import { type CollectionEntry, getCollection } from 'astro:content';
-import Main from '@layouts/Main.astro';
+import { type CollectionEntry, getCollection } from "astro:content";
+import Main from "@layouts/Main.astro";
 
 export async function getStaticPaths() {
-	const posts = await getCollection('handbook')
-	return posts.map((post) => ({
-		params: { slug: post.slug },
-		props: post,
-	}));
+  const posts = await getCollection("handbook");
+  return posts.map((post) => ({
+    params: { slug: post.slug },
+    props: post,
+  }));
 }
-type Props = CollectionEntry<'handbook'>;
+type Props = CollectionEntry<"handbook">;
 
 const isProd = import.meta.env.PROD;
-const {render, data} = Astro.props;
-const {title, lastModified} = data;
-const { Content, headings } = await render();
-
-if (isProd && lastModified === undefined) {
-	console.log({props: Astro.props, content: Content})
-}
+const { render, data } = Astro.props;
+const { title } = data;
+const {
+  Content,
+  headings,
+  remarkPluginFrontmatter: frontmatter,
+} = await render();
 ---
 
-<Main {headings} { ...data}>
-	<h2 class="text-2xl font-semibold mb-2">{title}</h2>
-		<!-- lastModified can be undefined in some rare circumstances (usually development only), this might fail in production if something went wrong. -->
-		<span>{(lastModified ?? (isProd ? null : new Date()))!.toLocaleDateString('en-us', {
-			year: 'numeric',
-			month: 'short',
-			day: 'numeric',
-		})}</span>
-        <div class="prose xl:prose-lg prose-zinc dark:prose-invert">
-			<Content />
-        </div>
+<Main {headings} {...data}>
+  <h2 class="text-2xl font-semibold mb-2">{title}</h2>
+  <!-- lastModified can be undefined in some rare circumstances (usually development only), this might fail in production if something went wrong. -->
+  <span
+    >{
+      new Date(frontmatter.lastModified).toLocaleDateString(
+        "en-us",
+        {
+          year: "numeric",
+          month: "short",
+          day: "numeric",
+        }
+      )
+    }</span
+  >
+  <div class="prose xl:prose-lg prose-zinc dark:prose-invert">
+    <Content />
+  </div>
 </Main>

src/plugins/remark-last-modified.ts

@@ -7,12 +7,14 @@ export const remarkModifiedTime: RemarkPlugins[number] = () => {
     const command = `git log -1 --pretty="format:%cI" "${filepath}"`;
     let result = execSync(command).toString().trim();
 
+    
     // File is not in git yet
     if (result === "") {
+      // TODO: Add specific error handling for when the file is not in git
       result = new Date().toISOString();
     }
     
     // @ts-ignore
-    file.data.astro.frontmatter.lastModified = result;
+    file.data.astro.frontmatter.lastModified = new Date(result);
   };
 };