feat: Improve perf of axe.run [WWD-1821]

lib/core/public/run-rules.js

@@ -3,6 +3,7 @@
 
 // Clean up after resolve / reject
 function cleanup() {
+	axe._nodeMap = undefined;
 	axe._tree = undefined;
 	axe._selectorData = undefined;
 }
@@ -18,6 +19,7 @@ function cleanup() {
 function runRules(context, options, resolve, reject) {
 	'use strict';
 	try {
+		// axe._nodeMap = new WeakMap();
 		context = new Context(context);
 		axe._tree = context.flatTree;
 		axe._selectorData = axe.utils.getSelectorData(context.flatTree);

lib/core/utils/flattened-tree.js

@@ -28,7 +28,7 @@ var axe = axe || { utils: {} };
  */
 function virtualDOMfromNode(node, shadowId) {
 	const vNodeCache = {};
-	return {
+	const vNode = {
 		shadowId: shadowId,
 		children: [],
 		actualNode: node,
@@ -47,6 +47,10 @@ function virtualDOMfromNode(node, shadowId) {
 			return vNodeCache._tabbableElements;
 		}
 	};
+	if (axe._nodeMap) {
+		axe._nodeMap.set(node, vNode);
+	}
+	return vNode;
 }
 
 /**
@@ -151,20 +155,5 @@ axe.utils.getFlattenedTree = function(node, shadowId) {
  * @param {Node}   node  The HTML DOM node
  */
 axe.utils.getNodeFromTree = function(vNode, node) {
-	var found;
-
-	if (vNode.actualNode === node) {
-		return vNode;
-	}
-	vNode.children.forEach(candidate => {
-		if (found) {
-			return;
-		}
-		if (candidate.actualNode === node) {
-			found = candidate;
-		} else {
-			found = axe.utils.getNodeFromTree(candidate, node);
-		}
-	});
-	return found;
+	return axe._nodeMap.get(node);
 };

lib/core/utils/is-hidden.js

@@ -8,7 +8,8 @@
  */
 axe.utils.isHidden = function isHidden(el, recursed) {
 	'use strict';
-	var parent;
+	var node = axe.utils.getNodeFromTree(axe._tree[0], el);
+	var parent, isHidden;
 
 	// 9 === Node.DOCUMENT
 	if (el.nodeType === 9) {
@@ -20,6 +21,10 @@ axe.utils.isHidden = function isHidden(el, recursed) {
 		el = el.host; // grab the host Node
 	}
 
+	if (typeof node.isHidden !== 'undefined') {
+		return node.isHidden;
+	}
+
 	var style = window.getComputedStyle(el, null);
 
 	if (
@@ -35,6 +40,7 @@ axe.utils.isHidden = function isHidden(el, recursed) {
 	}
 
 	parent = el.assignedSlot ? el.assignedSlot : el.parentNode;
-
-	return axe.utils.isHidden(parent, true);
+	isHidden = axe.utils.isHidden(parent, true);
+	node.isHidden = isHidden;
+	return isHidden;
 };