equality for ordered hashes

lib/mongo/util/ordered_hash.rb

@@ -35,6 +35,12 @@ class OrderedHash < Hash
     super(key, value)
   end
 
+  def ==(other)
+    !other.nil? &&
+      keys == other.keys &&
+      values == other.values
+  end
+
   def each
     @ordered_keys ||= []
     @ordered_keys.each { |k| yield k, self[k] }

tests/test_ordered_hash.rb

@@ -16,6 +16,33 @@ class OrderedHashTest < Test::Unit::TestCase
     assert_equal [], OrderedHash.new.keys
   end
 
+  def test_equality
+    a = OrderedHash.new
+    a['x'] = 1
+    a['y'] = 2
+
+    b = OrderedHash.new
+    b['y'] = 2
+    b['x'] = 1
+
+    c = OrderedHash.new
+    c['x'] = 1
+    c['y'] = 2
+
+    d = OrderedHash.new
+    d['x'] = 2
+    d['y'] = 3
+
+    e = OrderedHash.new
+    e['z'] = 1
+    e['y'] = 2
+
+    assert_equal a, c
+    assert_not_equal a, b
+    assert_not_equal a, d
+    assert_not_equal a, e
+  end
+
   def test_order_preserved
     assert_equal @ordered_keys, @oh.keys
   end