Enable passing root: false to #to_json

2 files changed, 69 insertions, 6 deletions

diff --git a/activemodel/lib/active_model/serializers/json.rb b/activemodel/lib/active_model/serializers/json.rb
index 0405705b35..4fbccd7419 100644
--- a/activemodel/lib/active_model/serializers/json.rb
+++ b/activemodel/lib/active_model/serializers/json.rb
@@ -32,8 +32,15 @@ module ActiveModel
       #   # => {"id": 1, "name": "Konata Izumi", "age": 16,
       #         "created_at": "2006/08/01", "awesome": true}
       #
-      # The remainder of the examples in this section assume +include_root_in_json+
-      # is false.
+      # This behavior can also be achieved by setting the <tt>:root</tt> option to +false+ as in:
+      #
+      #   user = User.find(1)
+      #   user.as_json(root: false)
+      #   # =>  {"id": 1, "name": "Konata Izumi", "age": 16,
+      #          "created_at": "2006/08/01", "awesome": true}
+      #
+      # The remainder of the examples in this section assume include_root_in_json is set to
+      # <tt>false</tt>.
       #
       # Without any +options+, the returned JSON string will include all the model's
       # attributes. For example:
@@ -83,7 +90,12 @@ module ActiveModel
       def as_json(options = nil)
         hash = serializable_hash(options)
 
-        if include_root_in_json
+        include_root = include_root_in_json
+        if options.try(:key?, :root)
+          include_root = options[:root]
+        end
+
+        if include_root
           custom_root = options && options[:root]
           hash = { custom_root || self.class.model_name.element => hash }
         end
@@ -91,9 +103,9 @@ module ActiveModel
         hash
       end
 
-      def from_json(json)
+      def from_json(json, include_root=include_root_in_json)
         hash = ActiveSupport::JSON.decode(json)
-        hash = hash.values.first if include_root_in_json
+        hash = hash.values.first if include_root
         self.attributes = hash
         self
       end
diff --git a/activemodel/test/cases/serializers/json_serialization_test.rb b/activemodel/test/cases/serializers/json_serialization_test.rb
index 500a5c575f..5e1e7d897a 100644
--- a/activemodel/test/cases/serializers/json_serialization_test.rb
+++ b/activemodel/test/cases/serializers/json_serialization_test.rb
@@ -8,6 +8,12 @@ class Contact
   include ActiveModel::Serializers::JSON
   include ActiveModel::Validations
 
+  def attributes=(hash)
+    hash.each do |k, v|
+      instance_variable_set("@#{k}", v)
+    end
+  end
+
   def attributes
     instance_values
   end unless method_defined?(:attributes)
@@ -34,7 +40,7 @@ class JsonSerializationTest < ActiveModel::TestCase
     assert_match %r{"preferences":\{"shows":"anime"\}}, json
   end
 
-  test "should not include root in json" do
+  test "should not include root in json (class method)" do
     begin
       Contact.include_root_in_json = false
       json = @contact.to_json
@@ -50,6 +56,13 @@ class JsonSerializationTest < ActiveModel::TestCase
     end
   end
 
+  test "should not include root in json (option)" do
+
+    json = @contact.to_json(:root => false)
+
+    assert_no_match %r{^\{"contact":\{}, json
+  end
+
   test "should include custom root in json" do
     json = @contact.to_json(:root => 'json_contact')
 
@@ -135,6 +148,44 @@ class JsonSerializationTest < ActiveModel::TestCase
     end
   end
 
+  test "from_json should set the object's attributes" do
+    json = @contact.to_json
+    result = Contact.new.from_json(json)
+
+    assert_equal result.name, @contact.name
+    assert_equal result.age, @contact.age
+    assert_equal Time.parse(result.created_at), @contact.created_at
+    assert_equal result.awesome, @contact.awesome
+    assert_equal result.preferences, @contact.preferences
+  end
+
+  test "from_json should work without a root (method parameter)" do
+    json = @contact.to_json(:root => false)
+    result = Contact.new.from_json(json, false)
+
+    assert_equal result.name, @contact.name
+    assert_equal result.age, @contact.age
+    assert_equal Time.parse(result.created_at), @contact.created_at
+    assert_equal result.awesome, @contact.awesome
+    assert_equal result.preferences, @contact.preferences
+  end
+
+  test "from_json should work without a root (class attribute)" do
+    begin
+      Contact.include_root_in_json = false
+      json = @contact.to_json
+      result = Contact.new.from_json(json)
+
+      assert_equal result.name, @contact.name
+      assert_equal result.age, @contact.age
+      assert_equal Time.parse(result.created_at), @contact.created_at
+      assert_equal result.awesome, @contact.awesome
+      assert_equal result.preferences, @contact.preferences
+    ensure
+      Contact.include_root_in_json = true
+    end
+  end
+
   test "custom as_json should be honored when generating json" do
     def @contact.as_json(options); { :name => name, :created_at => created_at }; end
     json = @contact.to_json