Add unit tests for Element#descendantOf.

CHANGELOG

@@ -1,3 +1,5 @@
+* Add unit tests for Element#descendantOf. (jddalton)
+
 * Form#serializeElements should not serialize file inputs. (kangax, Lonesome Boy)
 
 * Fix an issue with calling Event.pointer before the DOM is loaded. (kangax, jddalton) [#4 state:resolved]

test/unit/dom_test.js

@@ -715,6 +715,10 @@ new Test.Unit.Runner({
     
     $(document.body).insert(new Element('div', { id: 'impostor' }));
     this.assert(!$('impostor').descendantOf('ancestor'));
+    
+    // test descendantOf document
+    this.assert($(document.body).descendantOf(document));  
+    this.assert($(document.documentElement).descendantOf(document));  
   },  
   
   testChildOf: function() {