doc: remove TOC summary for pages with no TOC

Remove the table of contents summary for pages with no table of
contents. Currently, this affects at least index.html.

PR-URL: #37043
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>

doc/template.html

@@ -55,10 +55,7 @@ <h1>Node.js __VERSION__ Documentation</h1>
         <hr>
       </header>
 
-      <details id="toc" open>
-        <summary>Table of Contents</summary>
-        __TOC__
-      </details>
+      __TOC__
 
       <div id="apicontent">
         __CONTENT__

tools/doc/allhtml.js

@@ -59,9 +59,11 @@ let all = toc.replace(/index\.html/g, 'all.html')
 all = all.replace(/<title>.*?\| /, '<title>');
 
 // Insert the combined table of contents.
-const tocStart = /<\w+ id="toc"[^>]*>\s*<\w+>.*?<\/\w+>\s*/.exec(all);
+const tocStart = /<!-- TOC -->/.exec(all);
 all = all.slice(0, tocStart.index + tocStart[0].length) +
+  '<details id="toc" open><summary>Table of contents</summary>\n' +
   '<ul>\n' + contents + '</ul>\n' +
+  '</details>\n' +
   all.slice(tocStart.index + tocStart[0].length);
 
 // Replace apicontent with the concatenated set of apicontents from each source.

tools/doc/html.js

@@ -382,13 +382,19 @@ function buildToc({ filename, apilinks }) {
       node.children.push({ type: 'html', value: anchor });
     });
 
-    file.toc = unified()
-      .use(markdown)
-      .use(gfm)
-      .use(remark2rehype, { allowDangerousHtml: true })
-      .use(raw)
-      .use(htmlStringify)
-      .processSync(toc).toString();
+    if (toc !== '') {
+      file.toc = '<details id="toc" open><summary>Table of contents</summary>' +
+        unified()
+          .use(markdown)
+          .use(gfm)
+          .use(remark2rehype, { allowDangerousHtml: true })
+          .use(raw)
+          .use(htmlStringify)
+          .processSync(toc).toString() +
+        '</details>';
+    } else {
+      file.toc = '<!-- TOC -->';
+    }
   };
 }