From e6c5c08c18f5f114924e5e863dfc63d099b9cfc6 Mon Sep 17 00:00:00 2001
From: chaitanyav <me@chaitanyavellanki.com>
Date: Sat, 26 Jun 2010 01:52:20 -0700
Subject: [PATCH] Add OrderedHash#invert to preserve order in ruby 1.8

---
 activesupport/lib/active_support/ordered_hash.rb |    4 ++++
 activesupport/test/ordered_hash_test.rb          |    6 ++++++
 2 files changed, 10 insertions(+), 0 deletions(-)

diff --git a/activesupport/lib/active_support/ordered_hash.rb b/activesupport/lib/active_support/ordered_hash.rb
index a19d6c3..6b563b9 100644
--- a/activesupport/lib/active_support/ordered_hash.rb
+++ b/activesupport/lib/active_support/ordered_hash.rb
@@ -162,6 +162,10 @@ module ActiveSupport
         self
       end
 
+      def invert
+        OrderedHash[self.to_a.map!{|key_value_pair| key_value_pair.reverse}]
+      end
+
       def inspect
         "#<OrderedHash #{super}>"
       end
diff --git a/activesupport/test/ordered_hash_test.rb b/activesupport/test/ordered_hash_test.rb
index dca5c5d..0f11e59 100644
--- a/activesupport/test/ordered_hash_test.rb
+++ b/activesupport/test/ordered_hash_test.rb
@@ -250,4 +250,10 @@ class OrderedHashTest < Test::Unit::TestCase
     @updated_ordered_hash.update(:name => "Bob")
     assert_equal [:name],  @updated_ordered_hash.keys
   end
+
+  def test_invert
+    @ordered_hash = ActiveSupport::OrderedHash[[["foo", "FOO"], ["bar", "BAR"]]]
+    @inverted_ordered_hash = @ordered_hash.invert
+    assert_equal [["FOO", "foo"], ["BAR", "bar"]], @inverted_ordered_hash.to_a
+  end
 end
-- 
1.7.1