Added ariadescribedbyText

Author: mattscepter

lib/commons/aria/ariadescribedby-text.js

@@ -0,0 +1,46 @@
+/**
+ * Get the accessible name based on aria-describedby
+ *
+ * @deprecated Do not use Element directly. Pass VirtualNode instead
+ * @param {VirtualNode|Element} element
+ * @param {Object} context
+ * @property {Bool} inLabelledByContext Whether or not the lookup is part of aria-describedby reference
+ * @property {Bool} inControlContext Whether or not the lookup is part of a native label reference
+ * @property {Element} startNode First node in accessible name computation
+ * @property {Bool} debug Enable logging for formControlValue
+ * @return {string} Concatenated text value for referenced elements
+ */
+function ariadescribedbyText(element, context = {}) {
+  const { vNode } = axe.utils.nodeLookup(element);
+  if (vNode?.props.nodeType !== 1) {
+    return '';
+  }
+
+  if (
+    vNode.props.nodeType !== 1 ||
+    context.inLabelledByContext ||
+    context.inControlContext ||
+    !vNode.attr('aria-describedby')
+  ) {
+    return '';
+  }
+
+  const refs = axe.commons.dom
+    .idrefs(vNode, 'aria-describedby')
+    .filter(elm => elm);
+  return refs.reduce((accessibleName, elm) => {
+    const accessibleNameAdd = axe.commons.text.accessibleText(elm, {
+      // Prevent the infinite reference loop:
+      inLabelledByContext: true,
+      startNode: context.startNode || vNode,
+      ...context
+    });
+
+    if (!accessibleName) {
+      return accessibleNameAdd;
+    }
+    return `${accessibleName} ${accessibleNameAdd}`;
+  }, '');
+}
+
+export default ariadescribedbyText;

lib/commons/aria/index.js

@@ -6,6 +6,7 @@
 export { default as allowedAttr } from './allowed-attr';
 export { default as arialabelText } from './arialabel-text';
 export { default as arialabelledbyText } from './arialabelledby-text';
+export { default as ariadescribedbyText } from './ariadescribedby-text';
 export { default as getAccessibleRefs } from './get-accessible-refs';
 export { default as getElementUnallowedRoles } from './get-element-unallowed-roles';
 export { default as getExplicitRole } from './get-explicit-role';