fix formatting loss

frontend/src/components/stories/SlateEditor.tsx

@@ -70,6 +70,33 @@ const htmlToSlate = (html: string): Descendant[] => {
 
   const nodes: Descendant[] = [];
 
+  // Parse inline-formatted children of a block element into CustomText leaves,
+  // preserving bold/italic/underline/strikethrough marks.
+  const parseInlineChildren = (element: Element): CustomText[] => {
+    const children: CustomText[] = [];
+
+    const processNode = (node: Node, marks: Partial<CustomText> = {}) => {
+      if (node.nodeType === Node.TEXT_NODE) {
+        const text = node.textContent || '';
+        if (text) {
+          children.push({ text, ...marks });
+        }
+      } else if (node.nodeType === Node.ELEMENT_NODE) {
+        const el = node as Element;
+        const newMarks = { ...marks };
+        const tag = el.tagName.toLowerCase();
+        if (tag === 'strong' || tag === 'b') newMarks.bold = true;
+        if (tag === 'em' || tag === 'i') newMarks.italic = true;
+        if (tag === 'u') newMarks.underline = true;
+        if (tag === 's' || tag === 'del' || tag === 'strike') newMarks.strikethrough = true;
+        el.childNodes.forEach(child => processNode(child, newMarks));
+      }
+    };
+
+    element.childNodes.forEach(child => processNode(child));
+    return children.length > 0 ? children : [{ text: '' }];
+  };
+
   // Process all nodes in document order to maintain sequence
   const processChildNodes = (parentNode: Node): Descendant[] => {
     const results: Descendant[] = [];
@@ -82,19 +109,19 @@ const htmlToSlate = (html: string): Descendant[] => {
           case 'h1':
             results.push({
               type: 'heading-one',
-              children: [{ text: element.textContent || '' }]
+              children: parseInlineChildren(element)
             });
             break;
           case 'h2':
             results.push({
               type: 'heading-two',
-              children: [{ text: element.textContent || '' }]
+              children: parseInlineChildren(element)
             });
             break;
           case 'h3':
             results.push({
               type: 'heading-three',
-              children: [{ text: element.textContent || '' }]
+              children: parseInlineChildren(element)
             });
             break;
           case 'blockquote':
@@ -122,23 +149,26 @@ const htmlToSlate = (html: string): Descendant[] => {
             });
             break;
           }
-          case 'p':
-          case 'div': {
+          case 'p': {
             // Check if this paragraph contains mixed content (text + images)
             if (element.querySelector('img')) {
               // Process mixed content - handle both text and images in order
               results.push(...processChildNodes(element));
             } else {
-              const text = element.textContent || '';
-              if (text.trim()) {
-                results.push({
-                  type: 'paragraph',
-                  children: [{ text }]
-                });
+              const inlineChildren = parseInlineChildren(element);
+              if (inlineChildren.some(c => c.text.trim())) {
+                results.push({ type: 'paragraph', children: inlineChildren });
               }
             }
             break;
           }
+          case 'div': {
+            // Always recurse into divs: they may wrap headings or other block elements.
+            // Using textContent here would flatten everything into a single paragraph
+            // and silently drop any headings nested inside.
+            results.push(...processChildNodes(element));
+            break;
+          }
           case 'br':
             // Handle line breaks by creating empty paragraphs
             results.push({
@@ -194,34 +224,56 @@ const htmlToSlate = (html: string): Descendant[] => {
 const slateToHtml = (nodes: Descendant[]): string => {
   const htmlParts: string[] = [];
 
+  // Serialize a single leaf with its inline marks applied as HTML tags.
+  // Text content is escaped so literal <, >, & don't break the markup.
+  const serializeLeaf = (leaf: CustomText): string => {
+    let text = leaf.text
+      .replace(/&/g, '&amp;')
+      .replace(/</g, '&lt;')
+      .replace(/>/g, '&gt;');
+    if (leaf.bold) text = `<strong>${text}</strong>`;
+    if (leaf.italic) text = `<em>${text}</em>`;
+    if (leaf.underline) text = `<u>${text}</u>`;
+    if (leaf.strikethrough) text = `<s>${text}</s>`;
+    return text;
+  };
+
   nodes.forEach(node => {
     if (SlateElement.isElement(node)) {
       const element = node as CustomElement;
-      const text = SlateNode.string(node);
 
       switch (element.type) {
-        case 'heading-one':
-          htmlParts.push(`<h1>${text}</h1>`);
+        case 'heading-one': {
+          const inner = element.children.map(serializeLeaf).join('');
+          htmlParts.push(`<h1>${inner}</h1>`);
           break;
-        case 'heading-two':
-          htmlParts.push(`<h2>${text}</h2>`);
+        }
+        case 'heading-two': {
+          const inner = element.children.map(serializeLeaf).join('');
+          htmlParts.push(`<h2>${inner}</h2>`);
           break;
-        case 'heading-three':
-          htmlParts.push(`<h3>${text}</h3>`);
+        }
+        case 'heading-three': {
+          const inner = element.children.map(serializeLeaf).join('');
+          htmlParts.push(`<h3>${inner}</h3>`);
           break;
-        case 'image':
+        }
+        case 'image': {
           const attrs: string[] = [];
           if (element.src) attrs.push(`src="${element.src}"`);
           if (element.alt) attrs.push(`alt="${element.alt}"`);
           if (element.caption) attrs.push(`title="${element.caption}"`);
           htmlParts.push(`<img ${attrs.join(' ')} />`);
           break;
+        }
         case 'paragraph':
-        default:
-          htmlParts.push(text ? `<p>${text}</p>` : '<p></p>');
+        default: {
+          const inner = element.children.map(serializeLeaf).join('');
+          htmlParts.push(inner ? `<p>${inner}</p>` : '<p></p>');
           break;
         }
       }
+    }
   });
 
   const html = htmlParts.join('\n');