fix(is-hidden-for-everyone): count elements inside closed details as hidden

lib/commons/dom/is-hidden-for-everyone.js

@@ -5,10 +5,16 @@ import {
   nativelyHidden,
   displayHidden,
   visibilityHidden,
-  contentVisibiltyHidden
+  contentVisibiltyHidden,
+  detailsHidden
 } from './visibility-methods';
 
-const hiddenMethods = [displayHidden, visibilityHidden, contentVisibiltyHidden];
+const hiddenMethods = [
+  displayHidden,
+  visibilityHidden,
+  contentVisibiltyHidden,
+  detailsHidden
+];
 
 /**
  * Determine if an element is hidden from screenreaders and visual users

lib/commons/dom/visibility-methods.js

@@ -237,3 +237,25 @@ export function areaHidden(vNode, visibleFunction) {
 
   return refs.some(ref => !visibleFunction(ref));
 }
+
+/**
+ * Determine if element inside `details` is hidden
+ */
+export function detailsHidden(vNode) {
+  if (vNode.parent?.props.nodeName !== 'details') {
+    return false;
+  }
+
+  // first summary element is never hidden (subsequent ones are though)
+  if (vNode.props.nodeName === 'summary') {
+    const firstSummary = vNode.parent.children.find(
+      node => node.props.nodeName === 'summary'
+    );
+
+    if (firstSummary === vNode) {
+      return false;
+    }
+  }
+
+  return !vNode.parent.hasAttr('open');
+}

lib/core/_exposed-for-testing.js

@@ -33,7 +33,8 @@ import {
   scrollHidden,
   overflowHidden,
   clipHidden,
-  areaHidden
+  areaHidden,
+  detailsHidden
 } from '../commons/dom/visibility-methods';
 
 const _thisWillBeDeletedDoNotUse = {
@@ -71,7 +72,8 @@ const _thisWillBeDeletedDoNotUse = {
       scrollHidden,
       overflowHidden,
       clipHidden,
-      areaHidden
+      areaHidden,
+      detailsHidden
     }
   }
 };