Support passing a block to ActiveSupport::OrderedHash's merge and merge! [#4838 state:committed]

For better consistency with Ruby's own Hash implementation.
Signed-off-by: NXavier Noria <fxn@hashref.com>

activesupport/CHANGELOG

 *Rails 3.0.0 [Release Candidate] (unreleased)*
 
+* Ruby 1.9 compatibility: ActiveSupport::OrderedHash#merge and #merge! accept a block. #4838 [Paul Mucur]
+
 * Date#since, #ago, #beginning_of_day, #end_of_day, and #xmlschema honor now the user time zone if set. [Geoff Buesing]
 
 

activesupport/lib/active_support/ordered_hash.rb

@@ -130,12 +130,16 @@ def shift
       end
 
       def merge!(other_hash)
-        other_hash.each {|k,v| self[k] = v }
+        if block_given?
+          other_hash.each {|k,v| self[k] = yield(k, self[k], v) }
+        else
+          other_hash.each {|k,v| self[k] = v }
+        end
         self
       end
 
-      def merge(other_hash)
-        dup.merge!(other_hash)
+      def merge(other_hash, &block)
+        dup.merge!(other_hash, &block)
       end
 
       # When replacing with another hash, the initial order of our keys must come from the other hash -ordered or not.

activesupport/test/ordered_hash_test.rb

@@ -142,9 +142,22 @@ def test_merge
     assert_equal merged.length, @ordered_hash.length + other_hash.length
     assert_equal @keys + ['purple', 'violet'], merged.keys
 
+    another_hash = ActiveSupport::OrderedHash.new
+    another_hash['white'] = 'ff'
+    another_hash['black'] = '00'
+    merged_with_block = @ordered_hash.merge(another_hash) do |key, old_value, new_value|
+      new_value * 3
+    end
+    assert_equal 'ffffff', merged_with_block['white']
+    assert_equal '000000', merged_with_block['black']
+
     @ordered_hash.merge! other_hash
     assert_equal @ordered_hash, merged
     assert_equal @ordered_hash.keys, merged.keys
+
+    @ordered_hash.merge! another_hash
+    assert_equal 'ffffff', merged_with_block['white']
+    assert_equal '000000', merged_with_block['black']
   end
 
   def test_shift