Add ActiveSupport::Multibyte::Chars#ord method so that it returns correct Unicode value instead of falling back on String#ord in CoreExtensions, which is not multibyte compatible

[#1483 state:committed]

Signed-off-by: Jeremy Kemper <jeremy@bitsweat.net>

activesupport/CHANGELOG

@@ -1,5 +1,7 @@
 *2.3.0 [Edge]*
 
+* Multibyte: add multibyte-safe Chars#ord rather than falling back to String#ord.  #1483 [Jason Cheow]
+
 * I18n support for Array#to_sentence. Introduces support.array.words_connector, .two_words_connector, and .last_word_connector translation keys.  #1397 [Akira Matsuda]
 
 * Added ActiveSupport::OrderedHash#each_key and ActiveSupport::OrderedHash#each_value #1410 [Christoffer Sawicki]

activesupport/lib/active_support/multibyte/chars.rb

@@ -344,6 +344,14 @@ module ActiveSupport #:nodoc:
       end
       alias_method :[], :slice
 
+      # Converts first character in the string to Unicode value
+      #
+      # Example:
+      #   'こんにちは'.mb_chars.ord #=> 12371
+      def ord
+        self.class.u_unpack(@wrapped_string)[0]
+      end
+
       # Convert characters in the string to uppercase.
       #
       # Example:

activesupport/test/multibyte_chars_test.rb

@@ -397,6 +397,10 @@ class MultibyteCharsUTF8BehaviourTest < Test::Unit::TestCase
     assert_raise(ArgumentError) { @chars.slice(1, 1, 1) }
   end
 
+  def test_ord_should_return_unicode_value_for_first_character
+    assert_equal 12371, @chars.ord
+  end
+
   def test_upcase_should_upcase_ascii_characters
     assert_equal '', ''.mb_chars.upcase
     assert_equal 'ABC', 'aBc'.mb_chars.upcase