From 52741a3b7847e6f4a374ec992db863d5e031f3ca Mon Sep 17 00:00:00 2001
From: Yorick Peterse <yorickpeterse@gmail.com>
Date: Sat, 18 Jul 2015 01:05:06 +0200
Subject: [PATCH] Added XML::Node#each_ancestor

This method can be used to walk through the ancestor tree of a Node.
---
 lib/oga/xml/node.rb       | 20 ++++++++++++++++++++
 spec/oga/xml/node_spec.rb | 14 ++++++++++++++
 2 files changed, 34 insertions(+)

diff --git a/lib/oga/xml/node.rb b/lib/oga/xml/node.rb
index 201feb0..751edd3 100644
--- a/lib/oga/xml/node.rb
+++ b/lib/oga/xml/node.rb
@@ -214,6 +214,26 @@ module Oga
       def xml?
         !html?
       end
+
+      ##
+      # Yields all ancestor elements of the current node.
+      #
+      # @example
+      #  some_element.each_ancestor do |node|
+      #    # ...
+      #  end
+      #
+      # @yieldparam [Oga::XML::Node]
+      #
+      def each_ancestor
+        node = parent
+
+        while node.is_a?(XML::Element)
+          yield node
+
+          node = node.parent
+        end
+      end
     end # Element
   end # XML
 end # Oga
diff --git a/spec/oga/xml/node_spec.rb b/spec/oga/xml/node_spec.rb
index 34cb5ba..6d33f4d 100644
--- a/spec/oga/xml/node_spec.rb
+++ b/spec/oga/xml/node_spec.rb
@@ -276,4 +276,18 @@ describe Oga::XML::Node do
       node.xml?.should == false
     end
   end
+
+  describe '#each_ancestor' do
+    before do
+      @child2   = Oga::XML::Element.new(:name => 'c')
+      @child1   = Oga::XML::Element.new(:name => 'b', :children => [@child2])
+      @root     = Oga::XML::Element.new(:name => 'a', :children => [@child1])
+      @document = Oga::XML::Document.new(:children => [@root])
+    end
+
+    it 'yields all the ancestor elements' do
+      expect { |b| @child2.each_ancestor(&b) }
+        .to yield_successive_args(@child1, @root)
+    end
+  end
 end