Basic support for the XPath name() function.

lib/oga/xpath/evaluator.rb

@@ -711,6 +711,31 @@ module Oga
         return node.is_a?(XML::Element) ? node.name : ''
       end
 
+      ##
+      # Processes the `name()` function call.
+      #
+      # This function call is similar to `local-name()` (see
+      # {#on_call_local_name}) except that it includes the namespace name if
+      # present.
+      #
+      # @param [Oga::XML::NodeSet] context
+      # @param [Oga::XPath::Node] expression
+      # @return [Oga::XML::NodeSet]
+      #
+      def on_call_name(context, expression = nil)
+        node = function_node(context, expression)
+
+        if node.is_a?(XML::Element)
+          if node.namespace
+            return "#{node.namespace.name}:#{node.name}"
+          else
+            return node.name
+          end
+        else
+          return ''
+        end
+      end
+
       ##
       # Processes the `namespace-uri()` function call.
       #

spec/oga/xpath/evaluator/calls/name_spec.rb

@@ -0,0 +1,46 @@
+require 'spec_helper'
+
+describe Oga::XPath::Evaluator do
+  context 'name() function' do
+    before do
+      @document  = parse('<root xmlns:x="y"><x:a></x:a><b></b></root>')
+      @evaluator = described_class.new(@document)
+    end
+
+    context 'outside predicates' do
+      example 'return the name of the <x:a> node' do
+        @evaluator.evaluate('name(root/x:a)').should == 'x:a'
+      end
+
+      example 'return the name of the <b> node' do
+        @evaluator.evaluate('name(root/b)').should == 'b'
+      end
+
+      example 'return only the name of the first node in the set' do
+        @evaluator.evaluate('name(root/*)').should == 'x:a'
+      end
+
+      example 'return an empty string by default' do
+        @evaluator.evaluate('name(foo)').should == ''
+      end
+
+      example 'raise a TypeError for invalid argument types' do
+        block = lambda { @evaluator.evaluate('name("foo")') }
+
+        block.should raise_error(TypeError)
+      end
+    end
+
+    context 'inside predicates' do
+      before do
+        @set = @evaluator.evaluate('root/b[name()]')
+      end
+
+      it_behaves_like :node_set, :length => 1
+
+      example 'return the <b> node' do
+        @set[0].should == @document.children[0].children[1]
+      end
+    end
+  end
+end