fix(class-list): replace implementation

polyfill-lib/class-list/class-list.js

@@ -0,0 +1,71 @@
+let dpSupport = true;
+const defineGetter = function (object, name, fn, configurable) {
+	if (Object.defineProperty)
+		Object.defineProperty(object, name, {
+			configurable: false === dpSupport ? true : !!configurable,
+			get: fn
+		});
+	else object.__defineGetter__(name, fn);
+};
+/** Ensure the browser allows Object.defineProperty to be used on native JavaScript objects. */
+try {
+	defineGetter({}, "support");
+} catch (e) {
+	dpSupport = false;
+}
+/** Polyfills a property with a DOMTokenList */
+const addProp = function (o, name, attr) {
+	defineGetter(
+		o.prototype,
+		name,
+		function () {
+			let tokenList;
+
+			const THIS = this,
+				/** Prevent this from firing twice for some reason. What the hell, IE. */
+				gibberishProperty = "__defineGetter__" + "DEFINE_PROPERTY" + name;
+			if (THIS[gibberishProperty]) return tokenList;
+			THIS[gibberishProperty] = true;
+
+			/**
+			 * IE8 can't define properties on native JavaScript objects, so we'll use a dumb hack instead.
+			 *
+			 * What this is doing is creating a dummy element ("reflection") inside a detached phantom node ("mirror")
+			 * that serves as the target of Object.defineProperty instead. While we could simply use the subject HTML
+			 * element instead, this would conflict with element types which use indexed properties (such as forms and
+			 * select lists).
+			 */
+			if (false === dpSupport) {
+				let visage;
+				const mirror = addProp.mirror || document.createElement("div");
+				const reflections = mirror.childNodes;
+				const l = reflections.length;
+
+				for (let i = 0; i < l; ++i)
+					if (reflections[i]._R === THIS) {
+						visage = reflections[i];
+						break;
+					}
+
+				/** Couldn't find an element's reflection inside the mirror. Materialise one. */
+				visage || (visage = mirror.appendChild(document.createElement("div")));
+
+				tokenList = DOMTokenList.call(visage, THIS, attr);
+			} else tokenList = new DOMTokenList(THIS, attr);
+
+			defineGetter(THIS, name, function () {
+				return tokenList;
+			});
+			delete THIS[gibberishProperty];
+
+			return tokenList;
+		},
+		true
+	);
+};
+
+addProp(window.Element, "classList", "className");
+addProp(window.HTMLElement, "classList", "className");
+addProp(window.HTMLLinkElement, "relList", "rel");
+addProp(window.HTMLAnchorElement, "relList", "rel");
+addProp(window.HTMLAreaElement, "relList", "rel");