to_boolean support for truthy Ruby values

lib/oga/xpath/conversion.rb

@@ -80,6 +80,8 @@ module Oga
           bool = !value.zero?
         elsif value.respond_to?(:empty?)
           bool = !value.empty?
+        elsif value
+          bool = true
         end
 
         bool

spec/oga/xpath/conversion_spec.rb

@@ -220,5 +220,11 @@ describe Oga::XPath::Conversion do
     it 'returns false for an empty NodeSet' do
       described_class.to_boolean(node_set).should == false
     end
+
+    it 'returns true for an Element' do
+      element = Oga::XML::Element.new(:name => 'foo')
+
+      described_class.to_boolean(element).should == true
+    end
   end
 end