WIP

lib/active_model/array_serializer.rb

@@ -8,12 +8,7 @@ class ArraySerializer
 
     class << self
       def configuration
-        @configuration ||=
-          if self == ArraySerializer
-            Serializer::Configuration.global
-          else
-            superclass.configuration.build
-          end
+        @configuration ||= Serializer::ClassConfiguration.new super
       end
     end
 
@@ -25,7 +20,7 @@ def configuration
 
     def initialize(object, options = {})
       @object        = object
-      @configuration = self.class.configuration.build options
+      @configuration = Serializer::ArrayConfiguration.new self.class.configuration, options
     end
 
     def json_key

lib/active_model/default_serializer.rb

@@ -11,7 +11,7 @@ class DefaultSerializer
 
     def initialize(object, options = nil)
       @object = object
-      @configuration = Serializer::Configuration::Null.instance
+      @configuration = Serializer::InstanceConfiguration.new nil
     end
 
     def as_json(options = {})

lib/active_model/serializable.rb

@@ -1,5 +1,9 @@
 module ActiveModel
   module Serializable
+    def self.included(base)
+      base.extend ClassMethods
+    end
+
     def as_json(options={})
       if root = options.fetch(:root, json_key)
         hash = { root => serializable_object }
@@ -21,5 +25,11 @@ def serializable_data
     def embedded_in_root_associations
       {}
     end
+
+    module ClassMethods
+      def configuration
+        Serializer::GlobalConfiguration.instance
+      end
+    end
   end
 end

lib/active_model/serializer.rb

@@ -38,6 +38,7 @@ def serializer_for(resource)
         end
       end
 
+      attr_writer :configuration
       attr_accessor :_attributes, :_associations
 
       def root_name
@@ -49,12 +50,7 @@ def root_name
       def_delegators :dsl, :attributes, :has_one, :has_many, :embed, :root
 
       def configuration
-        @configuration ||=
-          if self == Serializer
-            Configuration.global
-          else
-            superclass.configuration.build
-          end
+        @configuration ||= ClassConfiguration.new super
       end
 
       private
@@ -72,7 +68,7 @@ def dsl
 
     def initialize(object, options = {})
       @object        = object
-      @configuration = self.class.configuration.build options
+      @configuration = InstanceConfiguration.new self.class.configuration, options
     end
 
     def json_key

lib/active_model/serializer/configuration.rb

@@ -3,77 +3,70 @@
 module ActiveModel
   class Serializer
     class Configuration
-      class Null
-        include Singleton
-
-        def method_missing(*)
-          nil
-        end
-
-        def respond_to?(*)
-          true
+      class << self
+        def options(*names)
+          names.each do |name|
+            attr_writer name
+
+            define_method name do
+              option name
+            end
+          end
         end
+        alias option options
       end
 
       attr_accessor :parent
 
-      class << self
-        def global
-          @global ||= new default_options
-        end
+      def initialize(parent, options = {})
+        self.parent = parent
 
-        def default_options
-          { embed: :objects, meta_key: :meta }
+        default_options.merge!(options).each do |name, value|
+          send "#{name}=", value
         end
       end
 
-      def build(options = {})
-        self.class.new options, self
+      def default_options
+        {}
       end
 
-      attr_reader :scope, :each_serializer, :resource_name
-      attr_writer :root, :meta, :meta_key
-      attr_accessor :wrap_in_array
-
-      def initialize(options = {}, parent = Null.instance)
-        @parent          = parent
-        @root            = read_option options, :root
-        @embed           = read_option options, :embed
-        @embed_in_root   = read_option options, :embed_in_root
-        @scope           = options[:scope]
-        @meta_key        = read_option options, :meta_key
-        @meta            = read_option options, meta_key
-        @wrap_in_array   = options[:_wrap_in_array]
-        @each_serializer = options[:each_serializer]
-        @resource_name   = options[:resource_name]
-      end
+      private
 
-      def root
-        return_first @root, parent.root
+      def own_option(name)
+        instance_variable_get "@#{name}"
       end
 
-      def embed
-        return_first @embed, parent.embed
+      def parent_option(name)
+        parent.send name if parent.respond_to? name
       end
 
-      def embed_in_root
-        return_first @embed_in_root, parent.embed_in_root
+      def option(name)
+        value = own_option name
+        value.nil? ? parent_option(name) : value
       end
+    end
 
-      def meta_key
-        return_first @meta_key, parent.meta_key
+    class SerializerConfiguration < Configuration
+      options :root, :embed, :embed_in_root
+
+      def default_options
+        { embed: :objects }
       end
+    end
 
-      def meta
-        return_first @meta, parent.meta
+    class GlobalConfiguration < SerializerConfiguration
+      include Singleton
+
+      def initialize
+        super nil
       end
+    end
 
-      # FIXME: Get rid of this mess.
+    class ClassConfiguration < SerializerConfiguration
       def embed_objects=(value)
         @embed = :objects if value
       end
 
-      # FIXME: Get rid of this mess.
       def embed_ids=(value)
         @embed = :ids if value
       end
@@ -85,16 +78,18 @@ def embed_objects
       def embed_ids
         [:ids, :id].include? embed
       end
+    end
 
-      private
+    class InstanceConfiguration < ClassConfiguration
+      options :scope, :meta, :meta_key, :wrap_in_array
 
-      def read_option(options, name)
-        options[name] || false if options.has_key? name
+      def default_options
+        super.merge! meta_key: :meta
       end
+    end
 
-      def return_first(*values)
-        values.compact.first
-      end
+    class ArrayConfiguration < InstanceConfiguration
+      options :each_serializer, :resource_name
     end
   end
 end

test/unit/active_model/serializer/configuration_test.rb

@@ -3,37 +3,141 @@
 module ActiveModel
   class Serializer
     class Configuration
-      class GlobalTest < Minitest::Test
-        def test_returns_global_configuration
-          assert_kind_of Configuration, Configuration.global
+      class Test < Minitest::Test
+        class ParentConfiguration < Configuration
+          options :root, :embed_in_root, :embed
+
+          def default_options
+            { embed: :objects }
+          end
         end
 
-        def test_global_configuration_returns_the_same_instance
-          assert_equal Configuration.global.object_id, Configuration.global.object_id
+        class ChildConfiguration < ParentConfiguration
+          options :scope
         end
 
-        def test_global_configuration_has_default_options_set
-          assert Configuration.default_options.all? do |name, value|
-            Configuration.global.send(name) == value
-          end
+        def setup
+          @parent = ParentConfiguration.new nil, root: 'root', embed_in_root: true
+          @child  = ChildConfiguration.new @parent, root: 'other'
+        end
+
+        def test_configuration_has_root_option
+          assert_equal 'root', @parent.root
+        end
+
+        def test_parent_has_default_embed_option
+          assert_equal :objects, @parent.embed
+        end
+
+        def test_child_returns_own_root_option
+          assert_equal 'other', @child.root
+        end
+
+        def test_child_returns_parent_embed_in_root_option
+          assert_equal true, @child.embed_in_root
+        end
+
+        def test_child_returns_nil_for_non_existing_parent_option
+          assert_equal nil, @child.scope
         end
       end
+    end
 
-      class OptionsTest < Minitest::Test
+    class SerializerConfiguration
+      class Test < Minitest::Test
         def setup
-          @configuration = Configuration.global.build(root: 'root', embed: :ids, embed_in_root: false)
+          @configuration = SerializerConfiguration.new nil, root: 'root'
+        end
+
+        def test_configuration_inherits_from_base_class
+          assert_kind_of Configuration, @configuration
         end
 
         def test_configuration_has_root_option
           assert_equal 'root', @configuration.root
         end
 
-        def test_configuration_has_embed_option
-          assert_equal :ids, @configuration.embed
+        def test_configuration_sets_root_option
+          @configuration.root = 'other'
+          assert_equal 'other', @configuration.root
+        end
+
+        def test_configuration_has_default_embed_option
+          assert_equal :objects, @configuration.embed
+        end
+      end
+    end
+
+    class GlobalConfiguration
+      class Test < Minitest::Test
+        def setup
+          @configuration = GlobalConfiguration.instance
+        end
+
+        def test_configuration_inherits_from_base_class
+          assert_kind_of Configuration, @configuration
+        end
+
+        def test_returns_singleton_configuration
+          other = GlobalConfiguration.instance
+          assert @configuration == other, "instances don't match"
+        end
+      end
+    end
+
+    class ClassConfiguration
+      class Test < Minitest::Test
+        def setup
+          @configuration = ClassConfiguration.new nil, root: 'root'
+        end
+
+        def test_configuration_inherits_from_base_class
+          assert_kind_of Configuration, @configuration
+        end
+
+        def test_configuration_has_root_option
+          assert_equal 'root', @configuration.root
+        end
+
+        def test_configuration_sets_root_option
+          @configuration.root = 'other'
+          assert_equal 'other', @configuration.root
+        end
+
+        def test_configuration_has_default_embed_option
+          assert_equal :objects, @configuration.embed
+        end
+      end
+    end
+
+    class InstanceConfiguration
+      class Test < Minitest::Test
+        def setup
+          @configuration = InstanceConfiguration.new nil, scope: :current_user
+        end
+
+        def test_configuration_inherits_from_base_class
+          assert_kind_of ClassConfiguration, @configuration
+        end
+
+        def test_configuration_has_root_option
+          assert_equal :current_user, @configuration.scope
+        end
+      end
+    end
+
+    class ArrayConfiguration
+      class Test < Minitest::Test
+        def setup
+          @configuration = ArrayConfiguration.new nil, resource_name: 'posts'
+        end
+
+        def test_configuration_inherits_from_base_class
+          assert_kind_of Configuration, @configuration
         end
 
-        def test_configuration_has_embed_in_root_option
-          assert_equal false, @configuration.embed_in_root
+        def test_configuration_has_resource_name_option
+          assert_equal 'posts', @configuration.resource_name
         end
       end
     end

test/unit/active_model/serializer/meta_test.rb

@@ -22,7 +22,7 @@ def test_meta
       end
 
       def test_meta_using_meta_key
-        profile_serializer = ProfileSerializer.new(@profile, root: 'profile', meta_key: :my_meta, my_meta: { total: 10 })
+        profile_serializer = ProfileSerializer.new(@profile, root: 'profile', meta_key: :my_meta, meta: { total: 10 })
 
         assert_equal({
           'profile' => {