Make ArraySerializer reuse Serializer embedded_in_root_associations code

lib/active_model/array_serializer.rb

@@ -30,34 +30,25 @@ module ActiveModel
       end
     end
 
+    def serializer_for(item)
+      serializer_class = @each_serializer || Serializer.serializer_for(item) || DefaultSerializer
+      serializer_class.new(item, @options)
+    end
+
     def serializable_array
       @object.map do |item|
-        serializer = @each_serializer || Serializer.serializer_for(item) || DefaultSerializer
-        serializer.new(item, @options).serializable_object
+        serializer_for(item).serializable_object
       end
     end
     alias_method :serializable_object, :serializable_array
 
-    def serializable_data
-      embedded_in_root_associations.merge!(super)
-    end
-
     def embedded_in_root_associations
-      hash = {}
-      @object.map do |item|
-        serializer_class = @each_serializer || Serializer.serializer_for(item) || DefaultSerializer
-        associations = serializer_class._associations
-        serializer = serializer_class.new(item, @options)
-        included_associations = serializer.filter(associations.keys)
-        associations.each do |(name, association)|
-          if included_associations.include? name
-            if association.embed_in_root?
-              hash[association.embedded_key] = serializer.serialize association
-            end
-          end
+      @object.each_with_object({}) do |item, hash|
+        serializer = serializer_for(item)
+        if serializer.respond_to?(:embedded_in_root_associations)
+          hash.merge!(serializer.embedded_in_root_associations)
         end
       end
-      hash
     end
   end
 end

lib/active_model/serializable.rb

@@ -11,11 +11,15 @@ module ActiveModel
     end
 
     def serializable_data
-      if respond_to?(:meta) && meta
-        { meta_key => meta }
-      else
-        {}
+      embedded_in_root_associations.tap do |hash|
+        if respond_to?(:meta) && meta
+          hash[meta_key] = meta
+        end
       end
     end
+
+    def embedded_in_root_associations
+      {}
+    end
   end
 end

lib/active_model/serializer.rb

@@ -141,10 +141,6 @@ end
       keys
     end
 
-    def serializable_data
-      embedded_in_root_associations.merge!(super)
-    end
-
     def embedded_in_root_associations
       associations = self.class._associations
       included_associations = filter(associations.keys)