inherits attributes, relationships and other settings from parent serializer

Author: shishirmk

lib/fast_jsonapi/object_serializer.rb

@@ -96,6 +96,19 @@ def is_collection?(resource)
     end
 
     class_methods do
+
+      def inherited(subclass)
+        super(subclass)
+        subclass.attributes_to_serialize = attributes_to_serialize.dup if attributes_to_serialize.present?
+        subclass.relationships_to_serialize = relationships_to_serialize.dup if relationships_to_serialize.present?
+        subclass.cachable_relationships_to_serialize = cachable_relationships_to_serialize.dup if cachable_relationships_to_serialize.present?
+        subclass.uncachable_relationships_to_serialize = uncachable_relationships_to_serialize.dup if uncachable_relationships_to_serialize.present?
+        subclass.transform_method = transform_method
+        subclass.cache_length = cache_length
+        subclass.race_condition_ttl = race_condition_ttl
+        subclass.cached = cached
+      end
+
       def reflected_record_type
         return @reflected_record_type if defined?(@reflected_record_type)
 

spec/lib/object_serializer_inheritance_spec.rb

@@ -0,0 +1,126 @@
+require 'spec_helper'
+
+describe FastJsonapi::ObjectSerializer do
+
+  after(:all) do
+    classes_to_remove = %i[
+      User
+      UserSerializer
+      Country
+      CountrySerializer
+      Employee
+      EmployeeSerializer
+    ]
+    classes_to_remove.each do |klass_name|
+      Object.send(:remove_const, klass_name) if Object.constants.include?(klass_name)
+    end
+  end
+
+  class User
+    attr_accessor :id, :first_name, :last_name
+
+    attr_accessor :address_ids, :country_id, :photo_id
+  end
+
+  class UserSerializer
+    include FastJsonapi::ObjectSerializer
+    set_type :user
+    attributes :first_name, :last_name
+
+    attribute :full_name do |user, params|
+      "#{user.first_name} #{user.last_name}"
+    end
+
+    has_many :addresses, cached: true
+    belongs_to :country
+    has_one :photo
+  end
+
+  class Country
+    attr_accessor :id, :name
+  end
+
+  class CountrySerializer
+    include FastJsonapi::ObjectSerializer
+    attributes :name
+  end
+
+  class Employee < User
+    attr_accessor :id, :location, :compensation
+    attr_accessor :account_id
+  end
+
+  class EmployeeSerializer < UserSerializer
+    include FastJsonapi::ObjectSerializer
+    attributes :location
+    attributes :compensation
+
+    has_one :account
+  end
+
+  context 'when testing inheritance of attributes' do
+
+    it 'includes parent attributes' do
+      subclass_attributes = EmployeeSerializer.attributes_to_serialize
+      superclass_attributes = UserSerializer.attributes_to_serialize
+      expect(subclass_attributes).to include(superclass_attributes)
+    end
+
+    it 'returns inherited attribute with a block correctly' do
+      e = Employee.new
+      e.id = 1
+      e.first_name = 'S'
+      e.last_name = 'K'
+      attributes_hash = EmployeeSerializer.new(e).serializable_hash[:data][:attributes]
+      expect(attributes_hash).to include(full_name: 'S K')
+    end
+
+    it 'includes child attributes' do
+      expect(EmployeeSerializer.attributes_to_serialize[:location]).to eq(:location)
+    end
+
+    it 'doesnt change parent class attributes' do
+      EmployeeSerializer
+      expect(UserSerializer.attributes_to_serialize).not_to have_key(:location)
+    end
+  end
+
+  context 'when testing inheritance of relationship' do
+    it 'includes parent relationships' do
+      subclass_relationships = EmployeeSerializer.relationships_to_serialize
+      superclass_relationships = UserSerializer.relationships_to_serialize
+      expect(subclass_relationships).to include(superclass_relationships)
+    end
+
+    it 'returns inherited relationship correctly' do
+      e = Employee.new
+      e.country_id = 1
+      relationships_hash = EmployeeSerializer.new(e).serializable_hash[:data][:relationships][:country]
+      expect(relationships_hash).to include(data: { id: "1", type: :country })
+    end
+
+    it 'includes child relationships' do
+      expect(EmployeeSerializer.relationships_to_serialize.keys).to include(:account)
+    end
+
+    it 'doesnt change parent class attributes' do
+      EmployeeSerializer
+      expect(UserSerializer.relationships_to_serialize.keys).not_to include(:account)
+    end
+
+    it 'includes parent cached relationships' do
+      subclass_relationships = EmployeeSerializer.cachable_relationships_to_serialize
+      superclass_relationships = UserSerializer.cachable_relationships_to_serialize
+      expect(subclass_relationships).to include(superclass_relationships)
+    end
+  end
+
+  context 'when test inheritence of other attributes' do
+
+    it 'inherits the tranform method' do
+      EmployeeSerializer
+      expect(UserSerializer.transform_method).to eq EmployeeSerializer.transform_method
+    end
+
+  end
+end