Does not ignore role=presentation or role=none elements

[hinderlingvolkart]

Does not ignore role=presentation or role=none elements

[natevw]

This project does not appear to be open source licensed so I hesitate to make a public copy of it and submit a PR. But since the source is available in case it helps others, the following patch may be of interest:

diff --git a/src/bookmarklet.js b/src/bookmarklet.js
index ae3becf..1c2ea5d 100644
--- a/src/bookmarklet.js
+++ b/src/bookmarklet.js
@@ -113,7 +113,8 @@ function getOutline() {
   for (var i = 0; i < els.length; i++) {
     var el = els[i];
     var visible = isVisible(els[i]);
-    var n = parseInt((el.getAttribute('role') == 'heading' && el.getAttribute('aria-level')) || el.nodeName.substr(1));
+    var n = getHeadingLevel(el);
+    if (n === null) continue;
     if (visible) {
       var wrongLevel = n > previousLevel && n !== (previousLevel + 1);
       previousLevel = n;
@@ -207,6 +208,11 @@ function isVisuallyHidden(el) {
   }
 }
 
+function getHeadingLevel(el) {
+  var role = el.getAttribute('role') || 'heading',
+      level = parseInt(el.getAttribute('aria-level') || el.nodeName.substr(1))
+  return (role === 'heading') ? level : null;
+}
 
 
 function highlightElement(el, disableAutoScroll) {

Building requires an older version of node, e.g. in a VM you might:

# install NVM
curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.1/install.sh | bash
. ~/.bashrc

# use NVM to install old node.js
nvm install 8

# use old nodejs to build project
npm install && npm start

The updated bookmarklet can then be found in the docs/index.html page.