feat(checks/label): support ARIA element internals properties

lib/checks/label/help-same-as-label-evaluate.js

@@ -1,5 +1,10 @@
-import { labelVirtual, accessibleText, sanitize } from '../../commons/text';
-import { idrefs } from '../../commons/dom';
+import {
+  labelVirtual,
+  accessibleTextVirtual,
+  sanitize
+} from '../../commons/text';
+import { getResolvedRefs } from '../../commons/dom';
+import { hasAriaValue } from '../../commons/aria';
 
 function helpSameAsLabelEvaluate(node, options, virtualNode) {
   const labelText = labelVirtual(virtualNode);
@@ -12,11 +17,11 @@ function helpSameAsLabelEvaluate(node, options, virtualNode) {
   if (!check) {
     check = '';
 
-    if (node.getAttribute('aria-describedby')) {
-      const ref = idrefs(node, 'aria-describedby');
+    if (hasAriaValue(virtualNode, 'aria-describedby')) {
+      const ref = getResolvedRefs(virtualNode, 'aria-describedby');
       check = ref
-        .map(thing => {
-          return thing ? accessibleText(thing) : '';
+        .map(vNode => {
+          return vNode ? accessibleTextVirtual(vNode) : '';
         })
         .join('');
     }

lib/checks/label/multiple-label-evaluate.js

@@ -2,7 +2,7 @@ import {
   getRootNode,
   isHiddenForEveryone,
   isVisibleToScreenReaders,
-  idrefs
+  getResolvedRefs
 } from '../../commons/dom';
 import { escapeSelector } from '../../core/utils';
 
@@ -40,8 +40,10 @@ function multipleLabelEvaluate(node) {
       return undefined;
     }
     // make sure the ONE AT visible label is in the list of idRefs of aria-labelledby
-    const labelledby = idrefs(node, 'aria-labelledby');
-    return !labelledby.includes(ATVisibleLabels[0]) ? undefined : false;
+    const labelledby = getResolvedRefs(node, 'aria-labelledby');
+    return !labelledby.some(ref => ref?.actualNode === ATVisibleLabels[0])
+      ? undefined
+      : false;
   }
 
   // only 1 CSS visible label

lib/checks/label/title-only-evaluate.js

@@ -1,11 +1,12 @@
 import { labelVirtual, titleText } from '../../commons/text';
+import { getAriaValue } from '../../commons/aria';
 
 function titleOnlyEvaluate(node, options, virtualNode) {
   const labelText = labelVirtual(virtualNode);
   const title = titleText(virtualNode);
-  const ariaDescribedBy = virtualNode.attr('aria-describedby');
+  const ariaDescribedBy = getAriaValue(virtualNode, 'aria-describedby');
 
-  return !labelText && !!(title || ariaDescribedBy);
+  return !labelText && !!(title || ariaDescribedBy?.value);
 }
 
 export default titleOnlyEvaluate;

test/checks/label/help-same-as-label.js

@@ -1,4 +1,6 @@
 describe('help-same-as-label', () => {
+  const { checkSetup, html } = axe.testUtils;
+  const checkEvaluate = axe.testUtils.getCheckEvaluate('help-same-as-label');
   const fixture = document.getElementById('fixture');
 
   afterEach(() => {
@@ -82,4 +84,18 @@ describe('help-same-as-label', () => {
       )
     );
   });
+
+  describe('ElementInternals', () => {
+    it('should return true if an element has a label and elementInternals aria-describedby with the same text', () => {
+      const params = checkSetup(html`
+        <div id="dby">Duplicate</div>
+        <testutils-element
+          id="target"
+          aria-label="Duplicate"
+          with-aria-describedby="dby"
+        ></testutils-element>
+      `);
+      assert.isTrue(checkEvaluate.apply(null, params));
+    });
+  });
 });

test/checks/label/multiple-label.js

@@ -243,6 +243,38 @@ describe('multiple-label', () => {
     );
   });
 
+  // ariaLabelledByElements (reflected AOM property) coverage adapted from
+  // @jcfranco's work in #5187 (issue #4943)
+  it('should return false when ariaLabelledByElements overrides aria-labelledby', () => {
+    fixtureSetup(html`
+      <input type="checkbox" id="F" aria-labelledby="G" />
+      <label for="F" id="G" aria-hidden="true">Please</label>
+      <label for="F" id="H">Excuse</label>
+    `);
+    const target = fixture.querySelector('#F');
+    target.ariaLabelledByElements = [fixture.querySelector('#H')];
+    assert.isFalse(
+      axe.testUtils
+        .getCheckEvaluate('multiple-label')
+        .call(checkContext, target)
+    );
+  });
+
+  it('should return false when ariaLabelledByElements overrides aria-labelledby with aria-label present', () => {
+    fixtureSetup(html`
+      <input type="checkbox" id="F" aria-labelledby="G" aria-label="Nope" />
+      <label for="F" id="G" aria-hidden="true">Please</label>
+      <label for="F" id="H">Excuse</label>
+    `);
+    const target = fixture.querySelector('#F');
+    target.ariaLabelledByElements = [fixture.querySelector('#H')];
+    assert.isFalse(
+      axe.testUtils
+        .getCheckEvaluate('multiple-label')
+        .call(checkContext, target)
+    );
+  });
+
   it('should return false given multiple labels, one label visible, and no aria-labelledby', () => {
     fixtureSetup(html`
       <input type="checkbox" id="I" />
@@ -337,4 +369,19 @@ describe('multiple-label', () => {
         .call(checkContext, shadowTarget.firstElementChild)
     );
   });
+
+  describe('ElementInternals', () => {
+    it('should return false given multiple labels, one label AT visible, and elementInternals aria-labelledby for AT visible', () => {
+      const checkEvaluate = axe.testUtils.getCheckEvaluate('multiple-label');
+      const params = axe.testUtils.checkSetup(html`
+        <label for="target" aria-hidden="true" id="l1">Please</label>
+        <label for="target" id="l2">Excuse</label>
+        <testutils-element
+          id="target"
+          with-aria-labelledby="l2"
+        ></testutils-element>
+      `);
+      assert.isFalse(checkEvaluate.call(checkContext, ...params));
+    });
+  });
 });

test/checks/label/title-only.js

@@ -1,4 +1,7 @@
 describe('title-only', () => {
+  const checkSetup = axe.testUtils.checkSetup;
+  const html = axe.testUtils.html;
+  const checkEvaluate = axe.testUtils.getCheckEvaluate('title-only');
   const fixture = document.getElementById('fixture');
 
   afterEach(() => {
@@ -61,4 +64,31 @@ describe('title-only', () => {
       )
     );
   });
+
+  it('should return false if aria-describedby is empty and there is no title or label', () => {
+    const node = document.createElement('input');
+    node.type = 'text';
+    node.setAttribute('aria-describedby', '');
+
+    fixture.appendChild(node);
+
+    axe.testUtils.flatTreeSetup(fixture);
+
+    assert.isFalse(
+      checkEvaluate(node, undefined, axe.utils.getNodeFromTree(node))
+    );
+  });
+
+  describe('ElementInternals', () => {
+    it('should return true if an element only has elementInternals aria-describedby', () => {
+      const params = checkSetup(html`
+        <div id="dby">description</div>
+        <testutils-element
+          id="target"
+          with-aria-describedby="dby"
+        ></testutils-element>
+      `);
+      assert.isTrue(checkEvaluate.apply(null, params));
+    });
+  });
 });