Allow ActiveRecord::Base.as_json to accept a frozen Hash

3 files changed, 16 insertions, 1 deletions

diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md
index bae2cab457..af4e42ba9a 100644
--- a/activerecord/CHANGELOG.md
+++ b/activerecord/CHANGELOG.md
@@ -1,3 +1,7 @@
+*   Allow ActiveRecord::Base#as_json to be passed a frozen Hash.
+
+    *Isaac Betesh*
+
 *   Deprecate locking records with unpersisted changes.
 
     *Marc Schütz*
diff --git a/activerecord/lib/active_record/serialization.rb b/activerecord/lib/active_record/serialization.rb
index 5a408e7b8e..db2bd0b55e 100644
--- a/activerecord/lib/active_record/serialization.rb
+++ b/activerecord/lib/active_record/serialization.rb
@@ -9,7 +9,7 @@ module ActiveRecord #:nodoc:
     end
 
     def serializable_hash(options = nil)
-      options = options.try(:clone) || {}
+      options = options.try(:dup) || {}
 
       options[:except] = Array(options[:except]).map(&:to_s)
       options[:except] |= Array(self.class.inheritance_column)
diff --git a/activerecord/test/cases/json_serialization_test.rb b/activerecord/test/cases/json_serialization_test.rb
index 155e858822..5a1d066aef 100644
--- a/activerecord/test/cases/json_serialization_test.rb
+++ b/activerecord/test/cases/json_serialization_test.rb
@@ -101,6 +101,17 @@ class JsonSerializationTest < ActiveRecord::TestCase
     assert_match %r{"favorite_quote":"Constraints are liberating"}, methods_json
   end
 
+  def test_uses_serializable_hash_with_frozen_hash
+    def @contact.serializable_hash(options = nil)
+      super({ only: %w(name) }.freeze)
+    end
+
+    json = @contact.to_json
+    assert_match %r{"name":"Konata Izumi"}, json
+    assert_no_match %r{awesome}, json
+    assert_no_match %r{age}, json
+  end
+
   def test_uses_serializable_hash_with_only_option
     def @contact.serializable_hash(options = nil)
       super(only: %w(name))