Adds test on proxying has_many through polymorphic

spec/integration/associations/belongs_to_polymorphic_spec.rb

@@ -118,6 +118,26 @@
     end
   end
 
+  context 'proxying a has_many association through a polymorphic association' do
+    it 'returns the associated documents' do
+      event = Event.create(restaurant: restaurant)
+
+      picture = Picture.create(imageable: event, mime: 'image/png')
+      guillaume = IdentifiedPerson.create(picture: picture,
+                                          fullname: 'Guillaume Briat')
+      alexandre = IdentifiedPerson.create(picture: picture,
+                                          fullname: 'Alexandre Astier')
+
+      picture = Picture.create(imageable: event, mime: 'image/png')
+      lionnel = IdentifiedPerson.create(picture: picture,
+                                        fullname: 'Lionnel Astier')
+      franck = IdentifiedPerson.create(picture: picture,
+                                       fullname: 'Franck Pitiot')
+
+      expect(event.people.to_a).to eql([guillaume, alexandre, lionnel, franck])
+    end
+  end
+
   context 'joining on the imageable belongs_to' do
     it 'fails' do
       expect do

spec/support/models.rb

@@ -157,6 +157,14 @@ def color=(value)
   end
 
   def load_belongs_to_polymorphic_models
+    define_class :IdentifiedPerson do
+      include NoBrainer::Document
+
+      field :fullname
+
+      belongs_to :picture
+    end
+
     define_class :Image do
       include NoBrainer::Document
 
@@ -171,13 +179,16 @@ def load_belongs_to_polymorphic_models
 
     define_class :Picture, Image do
       include NoBrainer::Document
+
+      has_many :people, class_name: 'IdentifiedPerson'
     end
 
     define_class :Event do
       include NoBrainer::Document
 
       belongs_to :restaurant
-      has_many :photos, as: :imageable, class_name: 'Picture'
+      has_many :photos, class_name: 'Picture', as: :imageable
+      has_many :people, through: :photos
     end
 
     define_class :Restaurant do