Really make include_root_in_json default to true [#3770 state:resolved]

2 files changed, 27 insertions, 18 deletions

diff --git a/activemodel/lib/active_model/serializers/json.rb b/activemodel/lib/active_model/serializers/json.rb
index ffdfbfcaaf..90305978c4 100644
--- a/activemodel/lib/active_model/serializers/json.rb
+++ b/activemodel/lib/active_model/serializers/json.rb
@@ -1,5 +1,5 @@
 require 'active_support/json'
-require 'active_support/core_ext/class/attribute_accessors'
+require 'active_support/core_ext/class/attribute'
 
 module ActiveModel
   module Serializers
@@ -10,7 +10,8 @@ module ActiveModel
       included do
         extend ActiveModel::Naming
 
-        cattr_accessor :include_root_in_json, :instance_writer => true
+        class_attribute :include_root_in_json
+        self.include_root_in_json = true
       end
 
       # Returns a JSON string representing the model. Some configuration is
@@ -92,7 +93,9 @@ module ActiveModel
       end
 
       def from_json(json)
-        self.attributes = ActiveSupport::JSON.decode(json)
+        hash = ActiveSupport::JSON.decode(json)
+        hash = hash.values.first if include_root_in_json
+        self.attributes = hash
         self
       end
     end
diff --git a/activemodel/test/cases/serializeration/json_serialization_test.rb b/activemodel/test/cases/serializeration/json_serialization_test.rb
index 7e89815c96..04b50e5bb8 100644
--- a/activemodel/test/cases/serializeration/json_serialization_test.rb
+++ b/activemodel/test/cases/serializeration/json_serialization_test.rb
@@ -22,35 +22,41 @@ class JsonSerializationTest < ActiveModel::TestCase
   end
 
   test "should include root in json" do
+    json = @contact.to_json
+
+    assert_match %r{^\{"contact":\{}, json
+    assert_match %r{"name":"Konata Izumi"}, json
+    assert_match %r{"age":16}, json
+    assert json.include?(%("created_at":#{ActiveSupport::JSON.encode(Time.utc(2006, 8, 1))}))
+    assert_match %r{"awesome":true}, json
+    assert_match %r{"preferences":\{"shows":"anime"\}}, json
+  end
+
+  test "should not include root in json" do
     begin
-      Contact.include_root_in_json = true
+      Contact.include_root_in_json = false
       json = @contact.to_json
 
-      assert_match %r{^\{"contact":\{}, json
+      assert_no_match %r{^\{"contact":\{}, json
       assert_match %r{"name":"Konata Izumi"}, json
       assert_match %r{"age":16}, json
       assert json.include?(%("created_at":#{ActiveSupport::JSON.encode(Time.utc(2006, 8, 1))}))
       assert_match %r{"awesome":true}, json
       assert_match %r{"preferences":\{"shows":"anime"\}}, json
     ensure
-      Contact.include_root_in_json = false
+      Contact.include_root_in_json = true
     end
   end
 
   test "should include custom root in json" do
-    begin
-      Contact.include_root_in_json = true
-      json = @contact.to_json(:root => 'json_contact')
+    json = @contact.to_json(:root => 'json_contact')
 
-      assert_match %r{^\{"json_contact":\{}, json
-      assert_match %r{"name":"Konata Izumi"}, json
-      assert_match %r{"age":16}, json
-      assert json.include?(%("created_at":#{ActiveSupport::JSON.encode(Time.utc(2006, 8, 1))}))
-      assert_match %r{"awesome":true}, json
-      assert_match %r{"preferences":\{"shows":"anime"\}}, json
-    ensure
-      Contact.include_root_in_json = false
-    end
+    assert_match %r{^\{"json_contact":\{}, json
+    assert_match %r{"name":"Konata Izumi"}, json
+    assert_match %r{"age":16}, json
+    assert json.include?(%("created_at":#{ActiveSupport::JSON.encode(Time.utc(2006, 8, 1))}))
+    assert_match %r{"awesome":true}, json
+    assert_match %r{"preferences":\{"shows":"anime"\}}, json
   end
 
   test "should encode all encodable attributes" do