fix(jqLite): ignore class methods on comment elements

Since c785267e jqLite uses setAttribute (rather than className property) in order to change classes. Some elements (eg. Comment) do not have this method which blows up.

jQuery silently ignores these method calls (because it uses className), so to get the same behavior as jQuery, we check for setAttribute method first.

2 files changed, 13 insertions, 2 deletions

diff --git a/src/jqLite.js b/src/jqLite.js
index 8660ce49..60c156e4 100644
--- a/src/jqLite.js
+++ b/src/jqLite.js
@@ -279,12 +279,13 @@ function JQLiteData(element, key, value) {
 }
 
 function JQLiteHasClass(element, selector) {
+  if (!element.getAttribute) return false;
   return ((" " + (element.getAttribute('class') || '') + " ").replace(/[\n\t]/g, " ").
       indexOf( " " + selector + " " ) > -1);
 }
 
 function JQLiteRemoveClass(element, cssClasses) {
-  if (cssClasses) {
+  if (cssClasses && element.setAttribute) {
     forEach(cssClasses.split(' '), function(cssClass) {
       element.setAttribute('class', trim(
           (" " + (element.getAttribute('class') || '') + " ")
@@ -296,7 +297,7 @@ function JQLiteRemoveClass(element, cssClasses) {
 }
 
 function JQLiteAddClass(element, cssClasses) {
-  if (cssClasses) {
+  if (cssClasses && element.setAttribute) {
     var existingClasses = (' ' + (element.getAttribute('class') || '') + ' ')
                             .replace(/[\n\t]/g, " ");
 
diff --git a/test/jqLiteSpec.js b/test/jqLiteSpec.js
index de9c74da..24920273 100644
--- a/test/jqLiteSpec.js
+++ b/test/jqLiteSpec.js
@@ -493,6 +493,16 @@ describe('jqLite', function() {
     });
 
 
+    it('should ignore comment elements', function() {
+      var comment = jqLite(document.createComment('something'));
+
+      comment.addClass('whatever');
+      comment.hasClass('whatever');
+      comment.toggleClass('whatever');
+      comment.removeClass('whatever');
+    });
+
+
     describe('hasClass', function() {
       it('should check class', function() {
         var selector = jqLite([a, b]);