From 44d5e0f9c5bd54a5fbfd265b805c55e65d95af11 Mon Sep 17 00:00:00 2001
From: homer <dimmokr@gmail.com>
Date: Mon, 28 May 2018 18:49:36 +0500
Subject: [PATCH] Fix serialization for nested nil includes with block

---
 lib/fast_jsonapi/serialization_core.rb |  2 +-
 spec/lib/object_serializer_spec.rb     |  7 +++++++
 spec/shared/contexts/movie_context.rb  | 19 ++++++++++++++++++-
 3 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/lib/fast_jsonapi/serialization_core.rb b/lib/fast_jsonapi/serialization_core.rb
index de138cd..668aebe 100644
--- a/lib/fast_jsonapi/serialization_core.rb
+++ b/lib/fast_jsonapi/serialization_core.rb
@@ -182,7 +182,7 @@ module FastJsonapi
           object = relationship[:object_block].call(record, params)
 
           return object.map(&:id) if object.respond_to? :map
-          return object.id
+          return object.try(:id)
         end
 
         record.public_send(relationship[:id_method_name])
diff --git a/spec/lib/object_serializer_spec.rb b/spec/lib/object_serializer_spec.rb
index 2d8c99e..7941f66 100644
--- a/spec/lib/object_serializer_spec.rb
+++ b/spec/lib/object_serializer_spec.rb
@@ -97,6 +97,13 @@ describe FastJsonapi::ObjectSerializer do
       expect(serializable_hash['data']['relationships']['owner']['data']).to be nil
     end
 
+    it 'returns correct json when belongs_to returns nil and there is a block for the relationship' do
+      movie.owner_id = nil
+      json = MovieSerializer.new(movie, {include: [:owner]}).serialized_json
+      serializable_hash = JSON.parse(json)
+      expect(serializable_hash['data']['relationships']['owner']['data']).to be nil
+    end
+
     it 'returns correct json when has_one returns nil' do
       supplier.account_id = nil
       json = SupplierSerializer.new(supplier).serialized_json
diff --git a/spec/shared/contexts/movie_context.rb b/spec/shared/contexts/movie_context.rb
index 7871f8b..a73e869 100644
--- a/spec/shared/contexts/movie_context.rb
+++ b/spec/shared/contexts/movie_context.rb
@@ -43,6 +43,13 @@ RSpec.shared_context 'movie class' do
         ac
       end
 
+      def owner
+        return unless owner_id
+        ow = Owner.new
+        ow.id = owner_id
+        ow
+      end
+
       def cache_key
         "#{id}"
       end
@@ -146,6 +153,14 @@ RSpec.shared_context 'movie class' do
       attr_accessor :id
     end
 
+    class Owner
+      attr_accessor :id
+    end
+
+    class OwnerSerializer
+      include FastJsonapi::ObjectSerializer
+    end
+
     # serializers
     class MovieSerializer
       include FastJsonapi::ObjectSerializer
@@ -153,7 +168,9 @@ RSpec.shared_context 'movie class' do
       # director attr is not mentioned intentionally
       attributes :name, :release_year
       has_many :actors
-      belongs_to :owner, record_type: :user
+      belongs_to :owner, record_type: :user do |object, params|
+        object.owner
+      end
       belongs_to :movie_type
       has_one :advertising_campaign
     end