implementing a bunch of NodeSet elements. closes #39

CHANGELOG.rdoc

@@ -19,7 +19,8 @@
   * Nokogiri::XML::Node#accept implements Visitor pattern
   * bin/nokogiri for easily examining documents (Thanks Yutaka HARA!)
   * Nokogiri::XML::NodeSet now supports more Array and Enumerable operators:
-    index, delete, slice, - (difference), + (concatenation), and & (intersection).
+    index, delete, slice, - (difference), + (concatenation), & (intersection),
+    push, pop, shift, ==
 
 * Bugfixes
 

lib/nokogiri/xml/node_set.rb

@@ -207,6 +207,35 @@ def to_xml *args
 
       alias :size :length
       alias :to_ary :to_a
+
+      ###
+      # Removes the last element from set and returns it, or +nil+ if
+      # the set is empty
+      def pop
+        return nil if length == 0
+        delete last
+      end
+
+      ###
+      # Returns the first element of the NodeSet and removes it.  Returns
+      # +nil+ if the set is empty.
+      def shift
+        return nil if length == 0
+        delete first
+      end
+
+      ###
+      # Equality -- Two NodeSets are equal if the contain the same number
+      # of elements and if each element is equal to the corresponding
+      # element in the other NodeSet
+      def == other
+        return false unless other.is_a?(Nokogiri::XML::NodeSet)
+        return false unless length == other.length
+        each_with_index do |node, i|
+          return false unless node == other[i]
+        end
+        true
+      end
     end
   end
 end

test/xml/test_node_set.rb

@@ -5,7 +5,58 @@ module XML
     class TestNodeSet < Nokogiri::TestCase
       def setup
         super
-        @xml = Nokogiri::XML.parse(File.read(XML_FILE), XML_FILE)
+        @xml = Nokogiri::XML(File.read(XML_FILE), XML_FILE)
+      end
+
+      def test_double_equal
+        assert node_set_one = @xml.xpath('//employee')
+        assert node_set_two = @xml.xpath('//employee')
+
+        assert_not_equal node_set_one.object_id, node_set_two.object_id
+
+        assert_equal node_set_one, node_set_two
+      end
+
+      def test_node_set_not_equal_to_string
+        node_set_one = @xml.xpath('//employee')
+        assert_not_equal node_set_one, "asdfadsf"
+      end
+
+      def test_out_of_order_not_equal
+        one = @xml.xpath('//employee')
+        two = @xml.xpath('//employee')
+        two.push two.shift
+        assert_not_equal one, two
+      end
+
+      def test_shorter_is_not_equal
+        node_set_one = @xml.xpath('//employee')
+        node_set_two = @xml.xpath('//employee')
+        node_set_two.delete(node_set_two.first)
+
+        assert_not_equal node_set_one, node_set_two
+      end
+
+      def test_pop
+        set = @xml.xpath('//employee')
+        last = set.last
+        assert_equal last, set.pop
+      end
+
+      def test_shift
+        set = @xml.xpath('//employee')
+        first = set.first
+        assert_equal first, set.shift
+      end
+
+      def test_shift_empty
+        set = Nokogiri::XML::NodeSet.new(@xml)
+        assert_nil set.shift
+      end
+
+      def test_pop_empty
+        set = Nokogiri::XML::NodeSet.new(@xml)
+        assert_nil set.pop
       end
 
       def test_first_takes_arguments