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fix: don't runs rules that select html on nested html elements #4969

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Merged
straker merged 6 commits into from
Jan 6, 2026
Merged

fix: don't runs rules that select html on nested html elements #4969

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aefa974
fix(html-has-lang,frame-test): don't process nested htmls
straker Dec 16, 2025
cc5ab4d
update all selectors that use html
straker Dec 16, 2025
b5ca2bd
forgot one
straker Dec 16, 2025
83a2840
another
straker Dec 16, 2025
8f996bc
fix selector in test
straker Dec 16, 2025
768d7b0
fix
straker Dec 16, 2025
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2 changes: 1 addition & 1 deletion lib/rules/bypass.json
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Original file line number Diff line number Diff line change
@@ -1,7 +1,7 @@
{
"id": "bypass",
"impact": "serious",
"selector": "html",
"selector": "html:not(html *)",
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@Garbee Garbee Dec 19, 2025

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I don't think this will work in IE 11. In that the not pseudo-selector only supports basic entry like :not(html), it doesn't support complex or list selectors that I'm aware of. This should be validated before merge, as it could break existing checks being ran in the wild.

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@WilcoFiers WilcoFiers Dec 22, 2025

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Doesn't matter. These don't actually get executed. Axe parses them and walks the tree with them.

@straker did you perf test this? This seems like an awfully slow selector.

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@straker straker Jan 5, 2026 •
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This isn't slow at all. The way the QSA code works is it matches each expression in turn. So it starts by matching all html elements on the page (an O(1) operation), then it runs the :not operator which is also a quick match using the matchesExpression logic on any found nodes. This barely adds any time to the selection, and testing this out didn't result in any difference in timings.

On https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/Your_first_WebExtension (size of the page does not matter for matching tag selectors), current axe-core average of five runs is 235.76ms. Using this code average of five runs is 220.52ms. This isn't a time savings it's just the variability of the runs. 15ms of time difference is not significant.

"pageLevel": true,
"matches": "bypass-matches",
"reviewOnFail": true,
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2 changes: 1 addition & 1 deletion lib/rules/css-orientation-lock.json
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@@ -1,7 +1,7 @@
{
"id": "css-orientation-lock",
"impact": "serious",
"selector": "html",
"selector": "html:not(html *)",
"tags": [
"cat.structure",
"wcag134",
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2 changes: 1 addition & 1 deletion lib/rules/document-title.json
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@@ -1,7 +1,7 @@
{
"id": "document-title",
"impact": "serious",
"selector": "html",
"selector": "html:not(html *)",
"matches": "is-initiator-matches",
"tags": [
"cat.text-alternatives",
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2 changes: 1 addition & 1 deletion lib/rules/frame-focusable-content.json
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{
"id": "frame-focusable-content",
"impact": "serious",
"selector": "html",
"selector": "html:not(html *)",
"matches": "frame-focusable-content-matches",
"tags": [
"cat.keyboard",
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2 changes: 1 addition & 1 deletion lib/rules/frame-tested.json
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@@ -1,7 +1,7 @@
{
"id": "frame-tested",
"impact": "critical",
"selector": "html, frame, iframe",
"selector": "html:not(html *), frame, iframe",
"tags": ["cat.structure", "best-practice", "review-item"],
"metadata": {
"description": "Ensure <iframe> and <frame> elements contain the axe-core script",
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2 changes: 1 addition & 1 deletion lib/rules/html-has-lang.json
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@@ -1,7 +1,7 @@
{
"id": "html-has-lang",
"impact": "serious",
"selector": "html",
"selector": "html:not(html *)",
"matches": "is-initiator-matches",
"tags": [
"cat.language",
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2 changes: 1 addition & 1 deletion lib/rules/html-lang-valid.json
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@@ -1,7 +1,7 @@
{
"id": "html-lang-valid",
"impact": "serious",
"selector": "html[lang]:not([lang=\"\"]), html[xml\\:lang]:not([xml\\:lang=\"\"])",
"selector": "html[lang]:not([lang=\"\"]):not(html *), html[xml\\:lang]:not([xml\\:lang=\"\"]):not(html *)",
"tags": [
"cat.language",
"wcag2a",
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2 changes: 1 addition & 1 deletion lib/rules/html-xml-lang-mismatch.json
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@@ -1,7 +1,7 @@
{
"id": "html-xml-lang-mismatch",
"impact": "moderate",
"selector": "html[lang][xml\\:lang]",
"selector": "html[lang][xml\\:lang]:not(html *)",
"matches": "xml-lang-mismatch-matches",
"tags": [
"cat.language",
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2 changes: 1 addition & 1 deletion lib/rules/landmark-one-main.json
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@@ -1,7 +1,7 @@
{
"id": "landmark-one-main",
"impact": "moderate",
"selector": "html",
"selector": "html:not(html *)",
"tags": ["cat.semantics", "best-practice"],
"metadata": {
"description": "Ensure the document has a main landmark",
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2 changes: 1 addition & 1 deletion lib/rules/page-has-heading-one.json
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@@ -1,7 +1,7 @@
{
"id": "page-has-heading-one",
"impact": "moderate",
"selector": "html",
"selector": "html:not(html *)",
"tags": ["cat.semantics", "best-practice"],
"metadata": {
"description": "Ensure that the page, or at least one of its frames contains a level-one heading",
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7 changes: 7 additions & 0 deletions test/integration/full/bypass/header1.html
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Expand Up @@ -24,6 +24,13 @@
<h2>This header will make the test pass.</h2>
<a href="http://www.deque.com">stuff</a>
<div id="mocha"></div>
<div id="additional"></div>
<script>
// only way to get a 2nd html element on the page is to create it with createElement
// if you try to do it through the html parser it won't work
var root = document.createElement('html');
document.getElementById('additional').append(root);
</script>
<script src="/test/testutils.js"></script>
<script src="pass-tests.js"></script>
<script src="/test/integration/adapter.js"></script>
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2 changes: 1 addition & 1 deletion test/integration/full/bypass/pass-tests.js
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Expand Up @@ -26,7 +26,7 @@ describe('bypass aria header test ' + window.location.pathname, function () {
});

it('should find html', function () {
assert.deepEqual(results.passes[0].nodes[0].target, ['html']);
assert.isTrue(results.passes[0].nodes[0].target[0].startsWith('html'));
});
});
});
7 changes: 7 additions & 0 deletions test/integration/full/css-orientation-lock/passes.html
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Expand Up @@ -26,5 +26,12 @@
<script src="/test/testutils.js"></script>
<script src="passes.js"></script>
<script src="/test/integration/adapter.js"></script>
<div id="additional"></div>
<script>
// only way to get a 2nd html element on the page is to create it with createElement
// if you try to do it through the html parser it won't work
var root = document.createElement('html');
document.getElementById('additional').append(root);
</script>
</body>
</html>
7 changes: 7 additions & 0 deletions test/integration/full/document-title/document-title-pass.html
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<body>
<iframe id="frame1" src="frames/level1.html"></iframe>
<div id="mocha"></div>
<div id="additional"></div>
<script>
// only way to get a 2nd html element on the page is to create it with createElement
// if you try to do it through the html parser it won't work
var root = document.createElement('html');
document.getElementById('additional').append(root);
</script>
<script src="/test/testutils.js"></script>
<script src="document-title-pass.js"></script>
<script src="/test/integration/adapter.js"></script>
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7 changes: 7 additions & 0 deletions test/integration/full/frame-tested/frame-tested-pass.html
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<body>
<iframe id="pass" src="frames/with-axe.html"></iframe>
<div id="mocha"></div>
<div id="additional"></div>
<script>
// only way to get a 2nd html element on the page is to create it with createElement
// if you try to do it through the html parser it won't work
var root = document.createElement('html');
document.getElementById('additional').append(root);
</script>
<script src="/test/testutils.js"></script>
<script src="frame-tested-pass.js"></script>
<script src="/test/integration/adapter.js"></script>
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7 changes: 7 additions & 0 deletions test/integration/full/html-has-lang/html-has-lang-pass.html
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Expand Up @@ -27,6 +27,13 @@
-->
<iframe id="frame1" src="frames/level1.html"></iframe>
<div id="mocha"></div>
<div id="additional"></div>
<script>
// only way to get a 2nd html element on the page is to create it with createElement
// if you try to do it through the html parser it won't work
var root = document.createElement('html');
document.getElementById('additional').append(root);
</script>
<script src="/test/testutils.js"></script>
<script src="html-has-lang-pass.js"></script>
<script src="/test/integration/adapter.js"></script>
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7 changes: 7 additions & 0 deletions test/integration/full/html-lang-valid/html-lang-valid.html
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Expand Up @@ -23,6 +23,13 @@
<body>
<iframe id="frame1" src="frames/level1.html"></iframe>
<div id="mocha"></div>
<div id="additional"></div>
<script>
// only way to get a 2nd html element on the page is to create it with createElement
// if you try to do it through the html parser it won't work
var root = document.createElement('html');
document.getElementById('additional').append(root);
</script>
<script src="/test/testutils.js"></script>
<script src="html-lang-valid.js"></script>
<script src="/test/integration/adapter.js"></script>
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7 changes: 7 additions & 0 deletions test/integration/full/landmark-one-main/landmark-one-main-pass1.html
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Expand Up @@ -22,6 +22,13 @@
<p>No main content</p>
<iframe id="frame1" src="frames/level1.html"></iframe>
<div id="mocha"></div>
<div id="additional"></div>
<script>
// only way to get a 2nd html element on the page is to create it with createElement
// if you try to do it through the html parser it won't work
var root = document.createElement('html');
document.getElementById('additional').append(root);
</script>
<script src="/test/testutils.js"></script>
<script src="landmark-one-main-pass1.js"></script>
<script src="/test/integration/adapter.js"></script>
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7 changes: 7 additions & 0 deletions test/integration/full/page-has-heading-one/page-has-heading-one-pass1.html
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<p>No h1 content</p>
<iframe id="frame1" src="frames/level1.html"></iframe>
<div id="mocha"></div>
<div id="additional"></div>
<script>
// only way to get a 2nd html element on the page is to create it with createElement
// if you try to do it through the html parser it won't work
var root = document.createElement('html');
document.getElementById('additional').append(root);
</script>
<script src="/test/testutils.js"></script>
<script src="page-has-heading-one-pass1.js"></script>
<script src="/test/integration/adapter.js"></script>
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