Links extraction: skip dfn panels (#1653)

Via #1584 (comment).

Aside dfn panels only contain links that already appear somewhere else in the
spec.

These links were extracted and categorized as `autolinks` when they appeared in
the final index of a Bikeshed spec, which essentially did not do anything
because the links had already been extracted as `autolinks` in any case.

The problem is that Respec also uses similar panels (but no `<aside>`), and
Bikeshed sometimes outputs the panels at the end of the document, and not
within the index itself as expected in the code. In these situations, the
links were extracted a second time, as `rawlinks`. Not extracting the panels
avoids duplication entirely.

src/browserlib/extract-links.mjs

@@ -24,12 +24,13 @@ export default function () {
     // self, the GitHub repo, the implementation report, and other
     // documents that don't need to appear in the list of references.
     // Also ignore links in <del> elements that appear when specs
-    // carry their diff (e.g. W3C Recs with candidate corrections)
-    if (n.closest('.head, del')) return;
+    // carry their diff (e.g. W3C Recs with candidate corrections).
+    // And then ignore links in aside dfn panels. They only contain internal
+    // links or links that already appear elsewhere in the spec.
+    if (n.closest('.head, del, .dfn-panel')) return;
     const pageUrl = n.href.split('#')[0];
     // links generated by authoring tools have data-link-type or data-xref-type set
-    // Bikeshed also adds automatic untyped links in the generatedindex ("ul.index aside")
-    let linkSet = n.dataset.linkType || n.dataset.xrefType || n.closest("ul.index aside") ? autolinks : rawlinks;
+    let linkSet = n.dataset.linkType || n.dataset.xrefType ? autolinks : rawlinks;
     if (!linkSet[pageUrl]) {
       linkSet[pageUrl] = {anchors: new Set()};
     }

tests/extract-links.js

@@ -44,13 +44,12 @@ const testLinks = [
     title: "extracts links with fragments",
     html: `<h1 id=title>Title</h1>
 <p><a href="https://dom.spec.whatwg.org/#ranges">DOM Standard</a></p>
-<p><a href="https://dom.spec.whatwg.org/#nodes" data-xref-type="dfn">DOM Standard</a></p><ul class="index"><li><aside><a href="https://dom.spec.whatwg.org/#element">Element</a></aside></li></ul>`,
+<p><a href="https://dom.spec.whatwg.org/#nodes" data-xref-type="dfn">DOM Standard</a></p>`,
     res: {
       autolinks: {
         "https://dom.spec.whatwg.org/": {
           "anchors": [
-            "nodes",
-	    "element"
+            "nodes"
           ]
         }
       },
@@ -63,6 +62,20 @@ const testLinks = [
       }
     }
   },
+
+  {
+    title: "does not extract links in aside dfns panels",
+    html: `<h1 id=title>Title</h1>
+<ul class="index"><li><aside class="dfn-panel"> <a href="https://dom.spec.whatwg.org/#element">Element</a></aside></li></ul>
+<aside class="dfn-panel"><a href="https://dom.spec.whatwg.org/#nodes">Nodes</a></aside>
+<div class="dfn-panel" role="dialog" hidden=""><div>
+  <a href="https://dom.spec.whatwg.org/#ranges">Permalink</a>
+</div></div>`,
+    res: {
+      autolinks: {},
+      rawlinks: {}
+    }
+  },
 ];
 
 describe("Links extraction", function () {