Feature/refactor embedded in root associations

lib/active_model/serializable.rb

@@ -3,7 +3,15 @@ module Serializable
     def as_json(options={})
       if root = options.fetch(:root, json_key)
         hash = { root => serializable_object }
-        hash.merge!(serializable_data)
+
+        serializable_data.each_pair do |key, value|
+          if hash[key].is_a?(Array) && value.is_a?(Array)
+            hash[key].concat(value)
+          else
+            hash[key] = value
+          end
+        end
+
         hash
       else
         serializable_object

lib/active_model/serializer.rb

@@ -128,15 +128,11 @@ def attributes
     end
 
     def associations
-      associations = self.class._associations
-      included_associations = filter(associations.keys)
-      associations.each_with_object({}) do |(name, association), hash|
-        if included_associations.include? name
-          if association.embed_ids?
-            hash[association.key] = serialize_ids association
-          elsif association.embed_objects?
-            hash[association.embedded_key] = serialize association
-          end
+      allowed_associations.each_with_object({}) do |association, hash|
+        if association.embed_ids?
+          hash[association.key] = serialize_ids association
+        elsif association.embed_objects?
+          hash[association.embedded_key] = serialize association
         end
       end
     end
@@ -152,23 +148,8 @@ def filter(keys)
     end
 
     def embedded_in_root_associations
-      associations = self.class._associations
-      included_associations = filter(associations.keys)
-      associations.each_with_object({}) do |(name, association), hash|
-        if included_associations.include? name
-          if association.embed_in_root?
-            association_serializer = build_serializer(association)
-            hash.merge! association_serializer.embedded_in_root_associations
-
-            serialized_data = association_serializer.serializable_object
-            key = association.root_key
-            if hash.has_key?(key)
-              hash[key].concat(serialized_data).uniq!
-            else
-              hash[key] = serialized_data
-            end
-          end
-        end
+      allowed_associations.each_with_object({}) do |association, hash|
+        embed_serialized_assocation(association, hash) if association.embed_in_root?
       end
     end
 
@@ -197,5 +178,42 @@ def serializable_object(options={})
       @wrap_in_array ? [hash] : hash
     end
     alias_method :serializable_hash, :serializable_object
+
+    protected
+
+    def embed_serialized_assocation(association, hash)
+      association_serializer = build_serializer(association)
+      embed_association_root_assocations(association_serializer, hash)
+      embed_data(hash, association.root_key, association_serializer.serializable_object)
+    end
+
+    def embed_association_root_assocations(association_serializer, hash)
+      return if association_serializer.send(:object).nil?
+
+      association_serializer.embedded_in_root_associations.each do |key, value|
+        embed_data(hash, key, value)
+      end
+    end
+
+    def embed_data(hash, key, data)
+      if hash[key].is_a?(Array) && data.is_a?(Array)
+        hash[key].concat(data).uniq!
+      else
+        hash[key] = data
+      end
+      hash
+    end
+
+    def allowed_associations
+      included_associations.values_at(*allowed_association_keys)
+    end
+
+    def allowed_association_keys
+      filter(included_associations.keys)
+    end
+
+    def included_associations
+      self.class._associations
+    end
   end
 end

test/fixtures/poro.rb

@@ -26,13 +26,24 @@ class Profile < Model
 end
 
 class Post < Model
+  def user
+    @user
+  end
+
   def comments
     @comments ||= [Comment.new(content: 'C1'),
                    Comment.new(content: 'C2')]
   end
 end
 
 class Comment < Model
+  def user
+    @user
+  end
+
+  def comments
+    @comments ||= []
+  end
 end
 
 ###

test/unit/active_model/array_serializer/serialization_test.rb

@@ -79,6 +79,33 @@ class << @post2
         PostSerializer._associations[:comments] = @old_association
       end
 
+      def test_associated_objects_of_recursive_instances_embedded_in_root
+        CommentSerializer.has_many :comments
+        @association = CommentSerializer._associations[:comments]
+
+        @association.embed = :ids
+        @association.embed_in_root = true
+
+        @comment1 = Comment.new(content: 'C1')
+        @comment2 = Comment.new(content: 'C2')
+
+        class << @comment1
+          attr_writer :comments
+        end
+        @comment1.comments = [Comment.new(content: 'C1-1')]
+
+        @serializer = ArraySerializer.new([@comment1, @comment2], root: :comments)
+        assert_equal({
+          comments: [
+            { content: 'C1', 'comment_ids' => @comment1.comments.map(&:object_id) },
+            { content: 'C2', 'comment_ids' => [] },
+            { content: 'C1-1', 'comment_ids' => []}
+          ]
+        }, @serializer.as_json)
+      ensure
+        CommentSerializer._associations = {}
+      end
+
       def test_embed_object_for_has_one_association_with_nil_value
         @association = UserSerializer._associations[:profile]
         @old_association = @association.dup

test/unit/active_model/serializer/embed_in_root_test.rb

@@ -0,0 +1,56 @@
+require 'test_helper'
+
+module ActiveModel
+  class Serializer
+    class EmbedInRootTest < Minitest::Test
+      def setup
+        @old_post_associations = PostSerializer._associations.dup
+        @old_comment_associations = CommentSerializer._associations.dup
+        @old_user_associations = UserSerializer._associations.dup
+
+        # reset associations
+        PostSerializer._associations = {}
+        UserSerializer._associations = {}
+
+        # set associations
+        PostSerializer.has_one :user, embed: :ids, embed_in_root: true
+        PostSerializer.has_many :comments, embed: :ids, embed_in_root: true
+        CommentSerializer.has_one :user, embed: :ids, embed_in_root: true
+
+        @post = Post.new({ title: 'Title 1', body: 'Body 1', date: '1/1/2000' })
+        @post_serializer = PostSerializer.new(@post)
+      end
+
+      def teardown
+        PostSerializer._associations = @old_post_associations
+        CommentSerializer._associations = @old_comment_associations
+        UserSerializer._associations = @old_user_associations
+      end
+
+      def test_associations_embedding_ids_including_objects_with_same_key_serialization_using_as_json
+        @user1 = User.new(name: 'post author')
+        @user2 = User.new(name: 'comment author')
+
+        @post.instance_variable_set(:@user, @user1)
+        @post.comments.first.instance_variable_set(:@user, @user2)
+
+        assert_equal({
+          'post' => {
+            title: 'Title 1',
+            body: 'Body 1',
+            'user_id' => @user1.object_id,
+            'comment_ids' => @post.comments.map(&:object_id)
+          },
+          'users' => [
+            { name: 'post author', email: nil },
+            { name: 'comment author', email: nil }
+          ],
+          comments: [
+            { content: 'C1', 'user_id' => @user2.object_id },
+            { content: 'C2', 'user_id' => nil }
+          ]
+        }, @post_serializer.as_json)
+      end
+    end
+  end
+end