feat(globals): deduce required window and document globals from context

doc/examples/jsdom/test/a11y.js

@@ -20,20 +20,6 @@ describe('axe', () => {
     </body>
   </html>`);
 
-	global.document = window.document;
-	global.window = window;
-
-	// needed by axios lib/helpers/isURLSameOrigin.js
-	global.navigator = window.navigator;
-
-	// needed by axe /lib/core/public/run.js
-	global.Node = window.Node;
-	global.NodeList = window.NodeList;
-
-	// needed by axe /lib/core/base/context.js
-	global.Element = window.Element;
-	global.Document = window.Document;
-
 	const axe = require('axe-core');
 	const config = {
 		rules: {

lib/commons/dom/is-node.js

@@ -9,7 +9,7 @@
  */
 function isNode(element) {
 	'use strict';
-	return element instanceof Node;
+	return element instanceof window.Node;
 }
 
 export default isNode;

lib/commons/dom/visually-contains.js

@@ -68,8 +68,8 @@ function contains(node, parent) {
 			style.overflow === 'scroll' ||
 			style.overflow === 'auto' ||
 			style.overflow === 'hidden' ||
-			parent instanceof HTMLBodyElement ||
-			parent instanceof HTMLHtmlElement
+			parent instanceof window.HTMLBodyElement ||
+			parent instanceof window.HTMLHtmlElement
 		);
 	}
 

lib/commons/dom/visually-overlaps.js

@@ -35,8 +35,8 @@ function visuallyOverlaps(rect, parent) {
 		return (
 			style.overflow === 'scroll' ||
 			style.overflow === 'auto' ||
-			parent instanceof HTMLBodyElement ||
-			parent instanceof HTMLHtmlElement
+			parent instanceof window.HTMLBodyElement ||
+			parent instanceof window.HTMLHtmlElement
 		);
 	}
 

lib/commons/table/get-scope.js

@@ -15,7 +15,7 @@ function getScope(cell) {
 	var role = cell.getAttribute('role');
 
 	if (
-		cell instanceof Element === false ||
+		cell instanceof window.Element === false ||
 		['TD', 'TH'].indexOf(cell.nodeName.toUpperCase()) === -1
 	) {
 		throw new TypeError('Expected TD or TH element');

lib/core/base/context.js

@@ -75,8 +75,11 @@ function pushUniqueFrameSelector(context, type, selectorArray) {
  */
 function normalizeContext(context) {
 	// typeof NodeList.length in PhantomJS === function
-	if ((context && typeof context === 'object') || context instanceof NodeList) {
-		if (context instanceof Node) {
+	if (
+		(context && typeof context === 'object') ||
+		context instanceof window.NodeList
+	) {
+		if (context instanceof window.Node) {
 			return {
 				include: [context],
 				exclude: []
@@ -140,7 +143,7 @@ function parseSelectorArray(context, type) {
 				})
 			);
 			break;
-		} else if (item && item.length && !(item instanceof Node)) {
+		} else if (item && item.length && !(item instanceof window.Node)) {
 			if (item.length > 1) {
 				pushUniqueFrameSelector(context, type, item);
 			} else {
@@ -152,8 +155,8 @@ function parseSelectorArray(context, type) {
 					})
 				);
 			}
-		} else if (item instanceof Node) {
-			if (item.documentElement instanceof Node) {
+		} else if (item instanceof window.Node) {
+			if (item.documentElement instanceof window.Node) {
 				result.push(context.flatTree[0]);
 			} else {
 				result.push(getNodeFromTree(item));
@@ -198,11 +201,11 @@ function getRootNode({ include, exclude }) {
 	for (var i = 0; i < selectors.length; ++i) {
 		var item = selectors[i];
 
-		if (item instanceof Element) {
+		if (item instanceof window.Element) {
 			return item.ownerDocument.documentElement;
 		}
 
-		if (item instanceof Document) {
+		if (item instanceof window.Document) {
 			return item.documentElement;
 		}
 	}

lib/core/public/run.js

@@ -5,8 +5,8 @@ function isContext(potential) {
 	switch (true) {
 		case typeof potential === 'string':
 		case Array.isArray(potential):
-		case Node && potential instanceof Node:
-		case NodeList && potential instanceof NodeList:
+		case window.Node && potential instanceof window.Node:
+		case window.NodeList && potential instanceof window.NodeList:
 			return true;
 
 		case typeof potential !== 'object':
@@ -87,6 +87,29 @@ function run(context, options, callback) {
 		throw new Error('No audit configured');
 	}
 
+	// if window or document are not defined and context was passed in
+	// we can use it to configure them
+	// NOTE: because our polyfills run first, the global window object
+	// always exists but may not have things we expect
+	const hasWindow = window && 'Node' in window && 'NodeList' in window;
+	const hasDoc = !!document;
+	if (!hasWindow || !hasDoc) {
+		if (!context || !context.ownerDocument) {
+			throw new Error(
+				'Required "window" or "document" globals not defined and cannot be deduced from the context. ' +
+					'Either set the globals before running or pass in a valid Element.'
+			);
+		}
+
+		if (!hasDoc) {
+			document = context.ownerDocument;
+		}
+
+		if (!hasWindow) {
+			window = document.defaultView;
+		}
+	}
+
 	let args = normalizeRunParams(context, options, callback);
 	context = args.context;
 	options = args.options;

lib/core/utils/check-helper.js

@@ -25,7 +25,7 @@ function checkHelper(checkResult, options, resolve, reject) {
 			checkResult.data = data;
 		},
 		relatedNodes: function(nodes) {
-			nodes = nodes instanceof Node ? [nodes] : toArray(nodes);
+			nodes = nodes instanceof window.Node ? [nodes] : toArray(nodes);
 			checkResult.relatedNodes = nodes.map(function(element) {
 				return new DqElement(element, options);
 			});