1 files changed, 39 insertions, 0 deletions
diff --git a/actionpack/lib/action_controller/testing/assertions/dom.rb b/actionpack/lib/action_controller/testing/assertions/dom.rb
new file mode 100644
index 0000000000..5ffe5f1883
--- /dev/null
+++ b/actionpack/lib/action_controller/testing/assertions/dom.rb
@@ -0,0 +1,39 @@
+module ActionController
+  module Assertions
+    module DomAssertions
+      # Test two HTML strings for equivalency (e.g., identical up to reordering of attributes)
+      #
+      # ==== Examples
+      #
+      #   # assert that the referenced method generates the appropriate HTML string
+      #   assert_dom_equal '<a href="http://www.example.com">Apples</a>', link_to("Apples", "http://www.example.com")
+      #
+      def assert_dom_equal(expected, actual, message = "")
+        clean_backtrace do
+          expected_dom = HTML::Document.new(expected).root
+          actual_dom   = HTML::Document.new(actual).root
+          full_message = build_message(message, "<?> expected to be == to\n<?>.", expected_dom.to_s, actual_dom.to_s)
+
+          assert_block(full_message) { expected_dom == actual_dom }
+        end
+      end
+      
+      # The negated form of +assert_dom_equivalent+.
+      #
+      # ==== Examples
+      #
+      #   # assert that the referenced method does not generate the specified HTML string
+      #   assert_dom_not_equal '<a href="http://www.example.com">Apples</a>', link_to("Oranges", "http://www.example.com")
+      #
+      def assert_dom_not_equal(expected, actual, message = "")
+        clean_backtrace do
+          expected_dom = HTML::Document.new(expected).root
+          actual_dom   = HTML::Document.new(actual).root
+          full_message = build_message(message, "<?> expected to be != to\n<?>.", expected_dom.to_s, actual_dom.to_s)
+
+          assert_block(full_message) { expected_dom != actual_dom }
+        end
+      end
+    end
+  end
+end