feat(dom.focusDisabled,dom.isVisibleForScreenreader): support the ine…

…rt attribute (#3857)

* feat(dom.focus-disabled,dom.is-visible-for-screenreader): support the inert attribute

* typos

* integration tests

lib/commons/dom/focus-disabled.js

@@ -1,6 +1,8 @@
 import AbstractVirtualNode from '../../core/base/virtual-node/abstract-virtual-node';
 import { getNodeFromTree } from '../../core/utils';
 import isHiddenForEveryone from './is-hidden-for-everyone';
+import isInert from './is-inert';
+
 // Source: https://developer.mozilla.org/en-US/docs/Web/HTML/Attributes/disabled
 const allowedDisabledNodeNames = [
   'button',
@@ -27,8 +29,9 @@ function focusDisabled(el) {
   const vNode = el instanceof AbstractVirtualNode ? el : getNodeFromTree(el);
 
   if (
-    isDisabledAttrAllowed(vNode.props.nodeName) &&
-    vNode.hasAttr('disabled')
+    (isDisabledAttrAllowed(vNode.props.nodeName) &&
+      vNode.hasAttr('disabled')) ||
+    isInert(vNode)
   ) {
     return true;
   }

lib/commons/dom/index.js

@@ -31,6 +31,7 @@ export { default as isHiddenForEveryone } from './is-hidden-for-everyone';
 export { default as isHTML5 } from './is-html5';
 export { default as isInTabOrder } from './is-in-tab-order';
 export { default as isInTextBlock } from './is-in-text-block';
+export { default as isInert } from './is-inert';
 export { default as isModalOpen } from './is-modal-open';
 export { default as isMultiline } from './is-multiline';
 export { default as isNativelyFocusable } from './is-natively-focusable';

lib/commons/dom/is-inert.js

@@ -0,0 +1,37 @@
+import memoize from '../../core/utils/memoize';
+
+/**
+ * Determines if an element is inside an inert subtree.
+ * @param {VirtualNode} vNode
+ * @param {Boolean} [options.skipAncestors] If the ancestor tree should not be used
+ * @return {Boolean} The element's inert state
+ */
+export default function isInert(vNode, { skipAncestors } = {}) {
+  if (skipAncestors) {
+    return isInertSelf(vNode);
+  }
+
+  return isInertAncestors(vNode);
+}
+
+/**
+ * Check the element for inert
+ */
+const isInertSelf = memoize(function isInertSelfMemoized(vNode) {
+  return vNode.hasAttr('inert');
+});
+
+/**
+ * Check the element and ancestors for inert
+ */
+const isInertAncestors = memoize(function isInertAncestorsMemoized(vNode) {
+  if (isInertSelf(vNode)) {
+    return true;
+  }
+
+  if (!vNode.parent) {
+    return false;
+  }
+
+  return isInertAncestors(vNode.parent);
+});

lib/commons/dom/is-visible-for-screenreader.js

@@ -3,6 +3,7 @@ import { getNodeFromTree } from '../../core/utils';
 import memoize from '../../core/utils/memoize';
 import isHiddenForEveryone from './is-hidden-for-everyone';
 import { ariaHidden, areaHidden } from './visibility-methods';
+import isInert from './is-inert';
 
 /**
  * Determine if an element is visible to a screen reader
@@ -21,7 +22,7 @@ export default function isVisibleToScreenReaders(vNode) {
  */
 const isVisibleToScreenReadersVirtual = memoize(
   function isVisibleToScreenReadersMemoized(vNode, isAncestor) {
-    if (ariaHidden(vNode)) {
+    if (ariaHidden(vNode) || isInert(vNode, { skipAncestors: true })) {
       return false;
     }
 

test/commons/dom/focus-disabled.js

@@ -51,6 +51,29 @@ describe('dom.focus-disabled', () => {
     assert.isTrue(focusDisabled(vNode));
   });
 
+  it('returns true for element with inert', () => {
+    const vNode = queryFixture('<button id="target" inert></button>');
+
+    assert.isTrue(focusDisabled(vNode));
+  });
+
+  it('returns true for ancestor with inert', () => {
+    const vNode = queryFixture(
+      '<div inert><div><button id="target"></button></div></div>'
+    );
+
+    assert.isTrue(focusDisabled(vNode));
+  });
+
+  it('returns true for ancestor with inert outside shadow tree', () => {
+    const vNode = queryShadowFixture(
+      '<div inert><div id="shadow"></div></div>',
+      '<input id="target"/>'
+    );
+
+    assert.isTrue(focusDisabled(vNode));
+  });
+
   describe('SerialVirtualNode', () => {
     it('returns false if element is hidden for everyone', () => {
       const vNode = new axe.SerialVirtualNode({

test/commons/dom/is-inert.js

@@ -0,0 +1,40 @@
+describe('dom.isInert', () => {
+  const isInert = axe.commons.dom.isInert;
+  const { queryFixture } = axe.testUtils;
+
+  it('returns true for element with "inert=false`', () => {
+    const vNode = queryFixture('<div id="target" inert="false"></div>');
+
+    assert.isTrue(isInert(vNode));
+  });
+
+  it('returns true for element with "inert`', () => {
+    const vNode = queryFixture('<div id="target" inert></div>');
+
+    assert.isTrue(isInert(vNode));
+  });
+
+  it('returns false for element without inert', () => {
+    const vNode = queryFixture('<div id="target"></div>');
+
+    assert.isFalse(isInert(vNode));
+  });
+
+  it('returns true for ancestor with inert', () => {
+    const vNode = queryFixture(
+      '<div inert><div><div id="target"></div></div></div>'
+    );
+
+    assert.isTrue(isInert(vNode));
+  });
+
+  describe('options.skipAncestors', () => {
+    it('returns false for ancestor with inert', () => {
+      const vNode = queryFixture(
+        '<div inert><div><div id="target"></div></div></div>'
+      );
+
+      assert.isFalse(isInert(vNode, { skipAncestors: true }));
+    });
+  });
+});

test/commons/dom/is-visible-for-screenreader.js

@@ -62,6 +62,13 @@ describe('dom.isVisibleToScreenReaders', function () {
     assert.isFalse(isVisibleToScreenReaders(vNode));
   });
 
+  it('should return false if `inert` is set', function () {
+    var vNode = queryFixture(
+      '<div id="target" inert>Hidden from screen readers</div>'
+    );
+    assert.isFalse(isVisibleToScreenReaders(vNode));
+  });
+
   it('should return false if `display: none` is set', function () {
     var vNode = queryFixture(
       '<div id="target" style="display: none">Hidden from screen readers</div>'
@@ -230,5 +237,30 @@ describe('dom.isVisibleToScreenReaders', function () {
       vNode.parent = parentVNode;
       assert.isFalse(isVisibleToScreenReaders(vNode));
     });
+
+    it('should return false if `inert` is set', function () {
+      var vNode = new axe.SerialVirtualNode({
+        nodeName: 'div',
+        attributes: {
+          inert: true
+        }
+      });
+      assert.isFalse(isVisibleToScreenReaders(vNode));
+    });
+
+    it('should return false if `inert` is set on parent', function () {
+      var vNode = new axe.SerialVirtualNode({
+        nodeName: 'div'
+      });
+      var parentVNode = new axe.SerialVirtualNode({
+        nodeName: 'div',
+        attributes: {
+          inert: true
+        }
+      });
+      parentVNode.children = [vNode];
+      vNode.parent = parentVNode;
+      assert.isFalse(isVisibleToScreenReaders(vNode));
+    });
   });
 });

test/integration/rules/aria-hidden-focus/aria-hidden-focus.html

@@ -27,6 +27,12 @@
   </label>
 </div>
 
+<div id="pass7" aria-hidden="true">
+  <div inert>
+    <button>hello</button>
+  </div>
+</div>
+
 <!-- ///////////////// -->
 <!-- Fail -->
 <!-- ///////////////// -->

test/integration/rules/aria-hidden-focus/aria-hidden-focus.json

@@ -16,7 +16,8 @@
     ["#pass3"],
     ["#pass4"],
     ["#pass5"],
-    ["#pass6"]
+    ["#pass6"],
+    ["#pass7"]
   ],
   "incomplete": [["#incomplete1"], ["#incomplete2"]]
 }

test/integration/rules/frame-focusable-content/frame-focusable-content.html

@@ -46,3 +46,8 @@
   height="0"
   id="inapplicable-3"
 ></iframe>
+<iframe
+  src="/integration/rules/frame-focusable-content/frames/focusable.html"
+  inert
+  id="inapplicable-4"
+></iframe>