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

lib/checks/aria/required-children.js

@@ -30,7 +30,7 @@ function ariaOwns(nodes, role) {
 		if (nodes[index] === null) {
 			continue;
 		}
-		let virtualTree = axe.utils.getNodeFromTree(axe._tree[0], nodes[index]);
+		let virtualTree = axe.utils.getNodeFromTree(nodes[index]);
 		if (owns(nodes[index], virtualTree, role, true)) {
 			return true;
 		}

lib/checks/aria/required-parent.js

@@ -73,7 +73,7 @@ var owners = getAriaOwners(node);
 if (owners) {
 	for (var i = 0, l = owners.length; i < l; i++) {
 		missingParents = getMissingContext(
-			axe.utils.getNodeFromTree(axe._tree[0], owners[i]),
+			axe.utils.getNodeFromTree(owners[i]),
 			missingParents,
 			true
 		);

lib/commons/aria/get-owned-virtual.js

@@ -16,7 +16,7 @@ aria.getOwnedVirtual = function getOwned({ actualNode, children }) {
 
 	return dom.idrefs(actualNode, 'aria-owns').reduce((ownedElms, element) => {
 		if (element) {
-			const virtualNode = axe.utils.getNodeFromTree(axe._tree[0], element);
+			const virtualNode = axe.utils.getNodeFromTree(element);
 			ownedElms.push(virtualNode);
 		}
 		return ownedElms;

lib/commons/aria/is-accessible-ref.js

@@ -17,39 +17,15 @@ function findDomNode(node, functor) {
  * @returns {Boolean}
  */
 aria.isAccessibleRef = function isAccessibleRef(node) {
+
+
+	// if while we generated the virtual node for each node we looked at
+	// the attributes of the node to see if it had any idref type attributes,
+	// we could store all those ids into a map and then this function would
+	// just have to look up the info in the map instead of the entire tree
+
 	node = node.actualNode || node;
-	let root = dom.getRootNode(node);
-	root = root.documentElement || root; // account for shadow roots
 	const id = node.id;
 
-	// Get all idref(s) attributes on the lookup table
-	const refAttrs = Object.keys(aria.lookupTable.attributes).filter(attr => {
-		const { type } = aria.lookupTable.attributes[attr];
-		return /^idrefs?$/.test(type);
-	});
-
-	// Find the first element that IDREF(S) the node
-	let refElm = findDomNode(root, elm => {
-		if (elm.nodeType !== 1) {
-			// Elements only
-			return;
-		}
-		if (
-			elm.nodeName.toUpperCase() === 'LABEL' &&
-			elm.getAttribute('for') === id
-		) {
-			return true;
-		}
-		// See if there are any aria attributes that reference the node
-		return refAttrs
-			.filter(attr => elm.hasAttribute(attr))
-			.some(attr => {
-				const attrValue = elm.getAttribute(attr);
-				if (aria.lookupTable.attributes[attr].type === 'idref') {
-					return attrValue === id;
-				}
-				return axe.utils.tokenList(attrValue).includes(id);
-			});
-	});
-	return typeof refElm !== 'undefined';
+	return typeof axe._idRefCache[id] !== 'undefined';
 };

lib/commons/aria/label-virtual.js

@@ -17,7 +17,7 @@ aria.labelVirtual = function({ actualNode }) {
 		ref = dom.idrefs(actualNode, 'aria-labelledby');
 		candidate = ref
 			.map(function(thing) {
-				const vNode = axe.utils.getNodeFromTree(axe._tree[0], thing);
+				const vNode = axe.utils.getNodeFromTree(thing);
 				return vNode ? text.visibleVirtual(vNode, true) : '';
 			})
 			.join(' ')
@@ -49,6 +49,6 @@ aria.labelVirtual = function({ actualNode }) {
  * @return {Mixed} String of visible text, or `null` if no label is found
  */
 aria.label = function(node) {
-	node = axe.utils.getNodeFromTree(axe._tree[0], node);
+	node = axe.utils.getNodeFromTree(node);
 	return aria.labelVirtual(node);
 };

lib/commons/dom/find-up.js

@@ -12,7 +12,7 @@
  */
 dom.findUp = function(element, target) {
 	return dom.findUpVirtual(
-		axe.utils.getNodeFromTree(axe._tree[0], element),
+		axe.utils.getNodeFromTree(element),
 		target
 	);
 };

lib/commons/dom/has-content-virtual.js

@@ -59,7 +59,7 @@ dom.hasContentVirtual = function(elm, noRecursion) {
  * @return {Boolean}
  */
 dom.hasContent = function hasContent(elm, noRecursion) {
-	elm = axe.utils.getNodeFromTree(axe._tree[0], elm);
+	elm = axe.utils.getNodeFromTree(elm);
 	return dom.hasContentVirtual(elm, noRecursion);
 };
 

lib/commons/dom/is-in-text-block.js

@@ -17,7 +17,7 @@ function getBlockParent(node) {
 	while (parentBlock && !isBlock(parentBlock)) {
 		parentBlock = dom.getComposedParent(parentBlock);
 	}
-	return axe.utils.getNodeFromTree(axe._tree[0], parentBlock);
+	return axe.utils.getNodeFromTree(parentBlock);
 }
 
 /**

lib/commons/text/accessible-text-virtual.js

@@ -11,7 +11,7 @@
  * @return {string}
  */
 text.accessibleText = function accessibleText(element, context) {
-	let virtualNode = axe.utils.getNodeFromTree(axe._tree[0], element); // throws an exception on purpose if axe._tree not correct
+	let virtualNode = axe.utils.getNodeFromTree(element); // throws an exception on purpose if axe._tree not correct
 	return text.accessibleTextVirtual(virtualNode, context);
 };
 

lib/commons/text/label-virtual.js

@@ -48,6 +48,6 @@ text.labelVirtual = function(node) {
  * @return {Mixed} String of visible text, or `null` if no label is found
  */
 text.label = function(node) {
-	node = axe.utils.getNodeFromTree(axe._tree[0], node);
+	node = axe.utils.getNodeFromTree(node);
 	return text.labelVirtual(node);
 };

lib/commons/text/visible-virtual.js

@@ -41,6 +41,6 @@ text.visibleVirtual = function(element, screenReader, noRecursing) {
  * @return {String}
  */
 text.visible = function(element, screenReader, noRecursing) {
-	element = axe.utils.getNodeFromTree(axe._tree[0], element);
+	element = axe.utils.getNodeFromTree(element);
 	return text.visibleVirtual(element, screenReader, noRecursing);
 };

lib/core/base/context.js

@@ -135,7 +135,7 @@ function parseSelectorArray(context, type) {
 			//eslint no-loop-func:0
 			result = result.concat(
 				nodeList.map(node => {
-					return axe.utils.getNodeFromTree(context.flatTree[0], node);
+					return axe.utils.getNodeFromTree(node);
 				})
 			);
 			break;
@@ -147,15 +147,15 @@ function parseSelectorArray(context, type) {
 				//eslint no-loop-func:0
 				result = result.concat(
 					nodeList.map(node => {
-						return axe.utils.getNodeFromTree(context.flatTree[0], node);
+						return axe.utils.getNodeFromTree(node);
 					})
 				);
 			}
 		} else if (item instanceof Node) {
 			if (item.documentElement instanceof Node) {
 				result.push(context.flatTree[0]);
 			} else {
-				result.push(axe.utils.getNodeFromTree(context.flatTree[0], item));
+				result.push(axe.utils.getNodeFromTree(item));
 			}
 		}
 	}

lib/core/public/run-rules.js

@@ -3,7 +3,7 @@
 
 // Clean up after resolve / reject
 function cleanup() {
-	axe._nodeMap = undefined;
+	axe._cache = undefined;
 	axe._tree = undefined;
 	axe._selectorData = undefined;
 }
@@ -19,7 +19,11 @@ function cleanup() {
 function runRules(context, options, resolve, reject) {
 	'use strict';
 	try {
-		// axe._nodeMap = new WeakMap();
+		axe._cache = {
+			nodeMap: new WeakMap(),
+			idRefs: {}
+		};
+
 		context = new Context(context);
 		axe._tree = context.flatTree;
 		axe._selectorData = axe.utils.getSelectorData(context.flatTree);

lib/core/utils/flattened-tree.js

@@ -1,6 +1,8 @@
 /*eslint no-use-before-define: 0*/
 var axe = axe || { utils: {} };
 
+const idRefRegex = /^idrefs?$/;
+
 /**
  * This implemnts the flatten-tree algorithm specified:
  * Originally here https://drafts.csswg.org/css-scoping/#flat-tree
@@ -27,6 +29,25 @@ var axe = axe || { utils: {} };
  * @return {Object} - the wrapped node
  */
 function virtualDOMfromNode(node, shadowId) {
+	const refAttrs = Object.keys(axe.commons.aria.lookupTable.attributes)
+    .filter(attr => {
+        const { type } = axe.commons.aria.lookupTable.attributes[attr];
+        return /^idrefs?$/.test(type);
+    });
+
+  // cache all idref attribute values so we can look them up in
+  // aria.isAccessibleRef
+  if (node.hasAttribute) {
+    refAttrs
+      .filter(attr => node.hasAttribute(attr))
+      .forEach(attr => {
+        const attrValue = elm.getAttribute(attr);
+        axe.utils.tokenList(attrValue).forEach(id => {
+          axe._cache.idRefs[id] = 1;
+        });
+      });
+	}
+
 	const vNodeCache = {};
 	const vNode = {
 		shadowId: shadowId,
@@ -47,9 +68,7 @@ function virtualDOMfromNode(node, shadowId) {
 			return vNodeCache._tabbableElements;
 		}
 	};
-	if (axe._nodeMap) {
-		axe._nodeMap.set(node, vNode);
-	}
+	axe._cahce.nodeMap.set(node, vNode);
 	return vNode;
 }
 
@@ -149,11 +168,10 @@ axe.utils.getFlattenedTree = function(node, shadowId) {
 };
 
 /**
- * Recursively return a single node from a virtual dom tree
+ * Return a single node from the virtual dom tree
  *
- * @param {Object} vNode The flattened, virtual DOM tree
  * @param {Node}   node  The HTML DOM node
  */
-axe.utils.getNodeFromTree = function(vNode, node) {
-	return axe._nodeMap.get(node);
+axe.utils.getNodeFromTree = function(node) {
+	return axe._cache.nodeMap.get(node);
 };

lib/core/utils/is-hidden.js

@@ -8,7 +8,7 @@
  */
 axe.utils.isHidden = function isHidden(el, recursed) {
 	'use strict';
-	var node = axe.utils.getNodeFromTree(axe._tree[0], el);
+	var node = axe.utils.getNodeFromTree(el);
 	var parent, isHidden;
 
 	// 9 === Node.DOCUMENT

lib/rules/color-contrast-matches.js

@@ -53,10 +53,7 @@ if (nodeName === 'LABEL' || nodeParentLabel) {
 	if (nodeParentLabel) {
 		relevantNode = nodeParentLabel;
 		// we need an input candidate from a parent to account for label children
-		relevantVirtualNode = axe.utils.getNodeFromTree(
-			axe._tree[0],
-			nodeParentLabel
-		);
+		relevantVirtualNode = axe.utils.getNodeFromTree(nodeParentLabel);
 	}
 	// explicit label of disabled input
 	let doc = axe.commons.dom.getRootNode(relevantNode);

test/testutils.js

@@ -92,6 +92,10 @@ testUtils.fixtureSetup = function(content) {
 	}
 	axe._tree = axe.utils.getFlattenedTree(fixture);
 	axe._selectorData = axe.utils.getSelectorData(axe._tree);
+	axe._cache = {
+		nodeMap: new WeakMap(),
+		idRefs: {}
+	};
 
 	return fixture;
 };