Fixed selecting serializer for deeply inherited resources

Author: piotrekbator

lib/graphiti/resource/polymorphism.rb

@@ -67,7 +67,8 @@ def resource_for_type(type)
         end
 
         def resource_for_model(model)
-          resource = children.find { |c| model.is_a?(c.model) }
+          resource = children.find { |c| model.class == c.model } ||
+            children.find { |c| model.is_a?(c.model) }
           if resource.nil?
             raise Errors::PolymorphicResourceChildNotFound.new(self, model: model)
           else

spec/fixtures/poro.rb

@@ -36,6 +36,7 @@ def klasses
           teams: PORO::Team,
           paypals: PORO::Paypal,
           visas: PORO::Visa,
+          gold_visas: PORO::GoldVisa,
           mastercards: PORO::Mastercard,
           visa_rewards: PORO::VisaReward,
           books: PORO::Book,
@@ -241,6 +242,9 @@ def initialize(*)
     end
   end
 
+  class GoldVisa < Visa
+  end
+
   class Mastercard < CreditCard
   end
 
@@ -397,7 +401,7 @@ class BioResource < ApplicationResource
   end
 
   class CreditCardResource < ApplicationResource
-    self.polymorphic = %w[PORO::VisaResource PORO::MastercardResource]
+    self.polymorphic = %w[PORO::VisaResource PORO::GoldVisaResource PORO::MastercardResource]
 
     def base_scope
       {type: [:visas, :mastercards]}
@@ -422,6 +426,9 @@ def base_scope
     has_many :visa_rewards
   end
 
+  class GoldVisaResource < VisaResource
+  end
+
   class MastercardResource < CreditCardResource
     attribute :description, :string do
       "mastercard description"

spec/polymorphic_resource_spec.rb

@@ -14,6 +14,8 @@
     it "returns the serializer of the child resource associated to the given model" do
       expect(instance.serializer_for(PORO::Visa.new))
         .to eq(PORO::VisaResource.serializer)
+      expect(instance.serializer_for(PORO::GoldVisa.new))
+        .to eq(PORO::GoldVisaResource.serializer)
     end
 
     context "when a polymorphic child" do

spec/schema_spec.rb

@@ -703,7 +703,7 @@ def self.name
       it "generates a polymorphic schema for the resource" do
         expect(schema[:resources][0][:polymorphic]).to eq(true)
         expect(schema[:resources][0][:children])
-          .to eq(["PORO::VisaResource", "PORO::MastercardResource"])
+          .to eq(["PORO::VisaResource", "PORO::GoldVisaResource", "PORO::MastercardResource"])
       end
     end