Merge pull request rails#4808 from route/mb_chars_as_json

Added as_json method for multibyte strings

activesupport/lib/active_support/multibyte/chars.rb

@@ -188,6 +188,10 @@ def tidy_bytes(force = false)
         chars(Unicode.tidy_bytes(@wrapped_string, force))
       end
 
+      def as_json(options = nil) #:nodoc:
+        to_s.as_json(options)
+      end
+
       %w(capitalize downcase reverse tidy_bytes upcase).each do |method|
         define_method("#{method}!") do |*args|
           @wrapped_string = send(method, *args).to_s

activesupport/test/multibyte_chars_test.rb

@@ -88,6 +88,9 @@ def test_concatenate_should_return_proxy_instance
     assert(('a'.mb_chars << 'b'.mb_chars).kind_of?(@proxy_class))
   end
 
+  def test_should_return_string_as_json
+    assert_equal UNICODE_STRING, @chars.as_json
+  end
 end
 
 class MultibyteCharsUTF8BehaviourTest < ActiveSupport::TestCase