fix(blog): restore table of contents, fix list item styling, resolve dynamic og image generation

app/[locale]/blog/[slug]/opengraph-image.tsx

@@ -8,6 +8,20 @@ export const size = OG_IMAGE_SIZE;
 export const contentType = 'image/png';
 export const runtime = 'nodejs';
 
+async function fetchImageAsBase64(url: string) {
+  try {
+    const res = await fetch(url);
+    if (!res.ok) return undefined;
+    const arrayBuffer = await res.arrayBuffer();
+    const buffer = Buffer.from(arrayBuffer);
+    const contentType = res.headers.get('content-type') || 'image/jpeg';
+    return `data:${contentType};base64,${buffer.toString('base64')}`;
+  } catch (error) {
+    console.error('Failed to fetch OG image:', url, error);
+    return undefined;
+  }
+}
+
 export default async function Image({
   params,
 }: {
@@ -32,12 +46,19 @@ export default async function Image({
       : `${SITE_URL}${post.frontmatter.featuredImage}`
     : undefined;
 
+  // Fetch image explicitly and convert to base64 because Satori sometimes struggles
+  // fetching remote URLs directly inside ImageResponse correctly in various environments.
+  let base64Image: string | undefined = undefined;
+  if (featuredImage) {
+    base64Image = await fetchImageAsBase64(featuredImage);
+  }
+
   return new ImageResponse(
     <OGImageTemplate
       title={post.frontmatter.title}
       description={post.frontmatter.excerpt}
       label={post.frontmatter.category || 'Blog'}
-      image={featuredImage}
+      image={base64Image || featuredImage}
     />,
     {
       ...OG_IMAGE_SIZE,

app/[locale]/blog/[slug]/page.tsx

@@ -1,12 +1,18 @@
 import { notFound, redirect } from 'next/navigation';
 import JsonLd from '@/components/JsonLd';
 import { SITE_URL } from '@/lib/schema';
-import { getPostBySlug, getAdjacentPosts, getReadingTime } from '@/lib/blog';
+import {
+  getPostBySlug,
+  getAdjacentPosts,
+  getReadingTime,
+  extractLexicalHeadings,
+} from '@/lib/blog';
 import { Metadata } from 'next';
 import Link from 'next/link';
 import Image from 'next/image';
 import PostNavigation from '@/components/blog/PostNavigation';
 import PowerCTA from '@/components/blog/PowerCTA';
+import TableOfContents from '@/components/blog/TableOfContents';
 import { Heading } from '@/components/ui';
 import { setRequestLocale } from 'next-intl/server';
 import BlogEngagementTracker from '@/components/analytics/BlogEngagementTracker';
@@ -67,6 +73,10 @@ export default async function BlogPost({ params }: BlogPostProps) {
 
   const { prev, next, isPrevRandom, isNextRandom } = await getAdjacentPosts(post.slug, locale);
 
+  // Convert Lexical content into a plain string to estimate reading time roughly
+  // Extract headings for TOC
+  const headings = extractLexicalHeadings(post.content?.root || post.content);
+
   // Convert Lexical content into a plain string to estimate reading time roughly
   const rawTextContent = JSON.stringify(post.content);
 
@@ -231,10 +241,10 @@ export default async function BlogPost({ params }: BlogPostProps) {
             </div>
           </div>
 
-          {/* Right Column: Sticky Sidebar - Temporarily Hidden without ToC */}
+          {/* Right Column: Sticky Sidebar - TOC */}
           <aside className="sticky-narrative-sidebar hidden lg:block">
-            <div className="space-y-12">
-              {/* Future Payload Table of Contents Implementation */}
+            <div className="space-y-12 lg:sticky lg:top-32">
+              <TableOfContents headings={headings} locale={locale} />
             </div>
           </aside>
         </div>

components/PayloadRichText.tsx

@@ -51,27 +51,74 @@ const jsxConverters: JSXConverters = {
   heading: ({ node, nodesToJSX }: any) => {
     const children = nodesToJSX({ nodes: node.children });
     const tag = node?.tag;
+
+    // Extract text to generate an ID for the TOC
+    // Lexical children might contain various nodes; we need a plain text representation
+    const textContent = node.children ? node.children.map((c: any) => c.text || '').join('') : '';
+    const id = textContent
+      ? textContent
+          .toLowerCase()
+          .replace(/ä/g, 'ae')
+          .replace(/ö/g, 'oe')
+          .replace(/ü/g, 'ue')
+          .replace(/ß/g, 'ss')
+          .replace(/[*_`]/g, '')
+          .replace(/[^\w\s-]/g, '')
+          .replace(/\s+/g, '-')
+          .replace(/-+/g, '-')
+          .replace(/^-+|-+$/g, '')
+      : undefined;
+
     if (tag === 'h1')
       return (
-        <h2 className="text-3xl md:text-4xl font-bold mt-12 mb-6 text-text-primary">{children}</h2>
+        <h2
+          id={id}
+          className="text-3xl md:text-4xl font-bold mt-12 mb-6 text-text-primary scroll-mt-24"
+        >
+          {children}
+        </h2>
       );
     if (tag === 'h2')
       return (
-        <h3 className="text-2xl md:text-3xl font-bold mt-10 mb-5 text-text-primary">{children}</h3>
+        <h3
+          id={id}
+          className="text-2xl md:text-3xl font-bold mt-10 mb-5 text-text-primary scroll-mt-24"
+        >
+          {children}
+        </h3>
       );
     if (tag === 'h3')
       return (
-        <h4 className="text-xl md:text-2xl font-bold mt-8 mb-4 text-text-primary">{children}</h4>
+        <h4
+          id={id}
+          className="text-xl md:text-2xl font-bold mt-8 mb-4 text-text-primary scroll-mt-24"
+        >
+          {children}
+        </h4>
       );
     if (tag === 'h4')
       return (
-        <h5 className="text-lg md:text-xl font-bold mt-6 mb-4 text-text-primary">{children}</h5>
+        <h5
+          id={id}
+          className="text-lg md:text-xl font-bold mt-6 mb-4 text-text-primary scroll-mt-24"
+        >
+          {children}
+        </h5>
       );
     if (tag === 'h5')
       return (
-        <h6 className="text-base md:text-lg font-bold mt-6 mb-4 text-text-primary">{children}</h6>
+        <h6
+          id={id}
+          className="text-base md:text-lg font-bold mt-6 mb-4 text-text-primary scroll-mt-24"
+        >
+          {children}
+        </h6>
       );
-    return <h6 className="text-base font-bold mt-6 mb-4 text-text-primary">{children}</h6>;
+    return (
+      <h6 id={id} className="text-base font-bold mt-6 mb-4 text-text-primary scroll-mt-24">
+        {children}
+      </h6>
+    );
   },
   list: ({ node, nodesToJSX }: any) => {
     const children = nodesToJSX({ nodes: node.children });
@@ -95,18 +142,18 @@ const jsxConverters: JSXConverters = {
     const children = nodesToJSX({ nodes: node.children });
     if (node?.checked != null) {
       return (
-        <li className="flex items-center gap-3 mb-2 leading-relaxed">
+        <li className="flex items-start gap-3 mb-2 leading-relaxed">
           <input
             type="checkbox"
             checked={node.checked}
             readOnly
-            className="mt-1 w-4 h-4 text-primary focus:ring-primary border-gray-300 rounded"
+            className="mt-1.5 w-4 h-4 text-primary focus:ring-primary border-gray-300 rounded shrink-0"
           />
-          <span>{children}</span>
+          <div className="flex-1">{children}</div>
         </li>
       );
     }
-    return <li className="mb-2 leading-relaxed">{children}</li>;
+    return <li className="mb-2 leading-relaxed block">{children}</li>;
   },
   quote: ({ node, nodesToJSX }: any) => {
     const children = nodesToJSX({ nodes: node.children });

lib/blog.ts

@@ -286,3 +286,38 @@ export function getHeadings(content: string): { id: string; text: string; level:
     return { id, text: cleanText, level };
   });
 }
+
+export function extractLexicalHeadings(
+  node: any,
+  headings: { id: string; text: string; level: number }[] = [],
+): { id: string; text: string; level: number }[] {
+  if (!node) return headings;
+
+  if (node.type === 'heading' && node.tag) {
+    const level = parseInt(node.tag.replace('h', ''));
+    const text = getTextContentFromLexical(node);
+    if (text) {
+      headings.push({
+        id: generateHeadingId(text),
+        text,
+        level,
+      });
+    }
+  }
+
+  if (node.children && Array.isArray(node.children)) {
+    node.children.forEach((child: any) => extractLexicalHeadings(child, headings));
+  }
+
+  return headings;
+}
+
+function getTextContentFromLexical(node: any): string {
+  if (node.type === 'text') {
+    return node.text || '';
+  }
+  if (node.children && Array.isArray(node.children)) {
+    return node.children.map(getTextContentFromLexical).join('');
+  }
+  return '';
+}

tests/og-image.test.ts

@@ -1,6 +1,7 @@
 import { describe, it, expect, beforeAll } from 'vitest';
 
-const BASE_URL = process.env.TEST_URL || process.env.NEXT_PUBLIC_BASE_URL || 'http://localhost:3000';
+const BASE_URL =
+  process.env.TEST_URL || process.env.NEXT_PUBLIC_BASE_URL || 'http://localhost:3000';
 
 describe('OG Image Generation', () => {
   const locales = ['de', 'en'];
@@ -18,7 +19,9 @@ describe('OG Image Generation', () => {
           return;
         }
       }
-      console.log(`\n⚠️  KLZ Application not detected at ${BASE_URL}. Skipping integration tests.\n`);
+      console.log(
+        `\n⚠️  KLZ Application not detected at ${BASE_URL}. Skipping integration tests.\n`,
+      );
     } catch (e) {
       isServerUp = false;
     }
@@ -34,7 +37,7 @@ describe('OG Image Generation', () => {
     // Check for PNG signature: 89 50 4E 47 0D 0A 1A 0A
     expect(bytes[0]).toBe(0x89);
     expect(bytes[1]).toBe(0x50);
-    expect(bytes[2]).toBe(0x4E);
+    expect(bytes[2]).toBe(0x4e);
     expect(bytes[3]).toBe(0x47);
 
     // Check that the image is not empty and has a reasonable size
@@ -49,7 +52,9 @@ describe('OG Image Generation', () => {
       await verifyImageResponse(response);
     }, 30000);
 
-    it(`should generate product OG image for ${locale} with slug ${productSlugs[0]}`, async ({ skip }) => {
+    it(`should generate product OG image for ${locale} with slug ${productSlugs[0]}`, async ({
+      skip,
+    }) => {
       if (!isServerUp) skip();
       const url = `${BASE_URL}/${locale}/api/og/product?slug=${productSlugs[0]}`;
       const response = await fetch(url);
@@ -64,11 +69,26 @@ describe('OG Image Generation', () => {
     }, 30000);
   });
 
-  it('should generate blog OG image', async ({ skip }) => {
+  it('should generate static blog overview OG image', async ({ skip }) => {
     if (!isServerUp) skip();
     const url = `${BASE_URL}/de/blog/opengraph-image`;
     const response = await fetch(url);
     await verifyImageResponse(response);
   }, 30000);
-});
 
+  it('should generate dynamic blog post OG image', async ({ skip }) => {
+    if (!isServerUp) skip();
+    // Assuming 'hello-world' or a newly created post slug.
+    // If it 404s, it still tests the routing, though 200 is expected for an actual post.
+    const url = `${BASE_URL}/de/blog/hello-world/opengraph-image`;
+    const response = await fetch(url);
+    // Even if the post "hello-world" doesn't exist and returns 404 in some environments,
+    // we should at least check it doesn't 500. We'll accept 200 or 404 as valid "working" states
+    // vs a 500 compilation/satori error.
+    expect([200, 404]).toContain(response.status);
+
+    if (response.status === 200) {
+      await verifyImageResponse(response);
+    }
+  }, 30000);
+});