Drop support of IE 6 - 9

Closes #370

Gruntfile.js

@@ -43,14 +43,13 @@ module.exports = function (grunt) {
 		eslint: {
 			grunt: 'Gruntfile.js',
 			source: 'src/**/*.js',
-			tests: ['test/**/*.js', '!test/polyfill.js']
+			tests: 'test/**/*.js'
 		},
 		uglify: {
 			options: {
 				compress: {
 					unsafe: true
 				},
-				screwIE8: false,
 				banner: '/*! <%= pkg.name %> v<%= pkg.version %> | <%= pkg.license %> */\n'
 			},
 			build: {

README.md

@@ -159,8 +159,6 @@ Cookies.getJSON('name'); // => { foo: 'bar' }
 Cookies.getJSON(); // => { name: { foo: 'bar' } }
 ```
 
-*Note: To support IE6-7 ([and IE 8 compatibility mode](http://stackoverflow.com/questions/4715373/json-object-undefined-in-internet-explorer-8)) you need to include the JSON-js polyfill: https://github.com/douglascrockford/JSON-js*
-
 ## Encoding
 
 This project is [RFC 6265](http://tools.ietf.org/html/rfc6265#section-4.1.1) compliant. All special characters that are not allowed in the cookie-name or cookie-value are encoded with each one's UTF-8 Hex equivalent using [percent-encoding](http://en.wikipedia.org/wiki/Percent-encoding).  

browserstack.json

@@ -9,7 +9,6 @@
     "firefox_previous",
     "ie_11",
     "ie_10",
-    "ie_9",
     "opera_latest",
     {
       "browser": "safari",

test/.eslintrc

@@ -10,7 +10,6 @@
     "lifecycle": true,
     "using": true,
     "quoted": true,
-    "addEvent": true,
     "loadFileSync": true
   },
   "rules": {}

test/index.html

@@ -7,7 +7,6 @@
 		<script src="../node_modules/qunitjs/qunit/qunit.js"></script>
 		<script>Cookies = 'existent global'</script>
 		<script src="../build/js.cookie.min.js"></script>
-		<script src="polyfill.js"></script>
 		<script src="utils.js"></script>
 		<script src="tests.js"></script>
 	</head>

test/tests.js

@@ -43,28 +43,6 @@ QUnit.test('percent character in cookie value mixed with encoded values', functi
 	assert.strictEqual(Cookies.get('bad'), 'foo%bar"baz%bax=', 'should read the percent character');
 });
 
-// github.com/carhartl/jquery-cookie/pull/88
-// github.com/carhartl/jquery-cookie/pull/117
-QUnit.test('malformed cookie value in IE', function (assert) {
-	assert.expect(1);
-	var done = assert.async();
-	// Sandbox in an iframe so that we can poke around with document.cookie.
-	var iframe = document.createElement('iframe');
-	iframe.src = 'malformed_cookie.html';
-	addEvent(iframe, 'load', function () {
-		if (iframe.contentWindow.ok) {
-			assert.strictEqual(iframe.contentWindow.testValue, 'two', 'reads all cookie values, skipping duplicate occurences of "; "');
-		} else {
-			// Skip the test where we can't stub document.cookie using
-			// Object.defineProperty. Seems to work fine in
-			// Chrome, Firefox and IE 8+.
-			assert.ok(true, 'N/A');
-		}
-		done();
-	});
-	document.body.appendChild(iframe);
-});
-
 // github.com/js-cookie/js-cookie/pull/171
 QUnit.test('missing leading semicolon', function (assert) {
 	assert.expect(1);
@@ -74,7 +52,7 @@ QUnit.test('missing leading semicolon', function (assert) {
 	var loadedSuccessfully = true;
 	iframe.src = 'missing_semicolon.html';
 
-	addEvent(iframe, 'load', function () {
+	iframe.addEventListener('load', function () {
 		iframe.contentWindow.onerror = function () {
 			loadedSuccessfully = false;
 		};
@@ -133,11 +111,7 @@ QUnit.test('Call to read cookie when there is a window.json variable globally',
 	window.json = true;
 	Cookies.set('boolean', true);
 	assert.strictEqual(typeof Cookies.get('boolean'), 'string', 'should not change the returned type');
-	// IE 6-8 throw an exception if trying to delete a window property
-	// See stackoverflow.com/questions/1073414/deleting-a-window-property-in-ie/1824228
-	try {
-		delete window.json;
-	} catch (e) {}
+	delete window.json;
 });
 
 QUnit.module('write', lifecycle);

test/utils.js

@@ -4,10 +4,6 @@
 	window.lifecycle = {
 		afterEach: function () {
 			// Remove the cookies created using js-cookie default attributes
-			// Note: Using `Object.keys(Cookies.get()).forEach(Cookies.remove)`
-			// would cause IE 6 + 7 to break with a "Object doesn't support
-			// this property or method" error, thus wrapping it with a
-			// function.
 			Object.keys(Cookies.get()).forEach(function (cookie) {
 				Cookies.remove(cookie);
 			});
@@ -20,15 +16,6 @@
 		}
 	};
 
-	window.addEvent = function (element, eventName, fn) {
-		var method = 'addEventListener';
-		if (element.attachEvent) {
-			eventName = 'on' + eventName;
-			method = 'attachEvent';
-		}
-		element[ method ](eventName, fn);
-	};
-
 	window.using = function (assert) {
 		function getQuery(key) {
 			var queries = location.href.split('?')[1];
@@ -58,7 +45,7 @@
 							'&value=' + encodeURIComponent(value)
 						].join('');
 						var done = assert.async();
-						addEvent(iframe, 'load', function () {
+						iframe.addEventListener('load', function () {
 							var iframeDocument = iframe.contentWindow.document;
 							var root = iframeDocument.documentElement;
 							var content = root.textContent;