Demonstrate presence of bug mentioned in #1686

test/fixtures/poro.rb

@@ -251,4 +251,85 @@ def maker
   cache only: [:id]
   attributes :id
 end
+
+module ModelWithAssociations
+  class Model < ActiveModelSerializers::Model
+    attr_accessor :id, :title, :body, :comments, :blog, :author
+  end
+  class Comment < ActiveModelSerializers::Model
+    attr_accessor :id, :body
+  end
+  class Blog < ActiveModelSerializers::Model
+    attr_accessor :id, :name
+  end
+  class Author < ActiveModelSerializers::Model
+    attr_accessor :id, :first_name, :last_name, :models
+  end
+
+  class AuthorSerializer < ActiveModel::Serializer
+    attributes :id, :first_name, :last_name
+
+    has_many :models, embed: :ids
+    has_one :bio
+  end
+  class BlogSerializer < ActiveModel::Serializer
+    attributes :id, :name
+  end
+  class CommentSerializer < ActiveModel::Serializer
+    attributes :id, :body
+
+    belongs_to :model
+    belongs_to :author
+  end
+  class ModelSerializer < ActiveModel::Serializer
+    attributes :id, :title, :body
+
+    has_many :comments, serializer: CommentSerializer
+    belongs_to :blog, serializer: BlogSerializer
+    belongs_to :author, serializer: AuthorSerializer
+
+    link(:model_authors) { 'https://example.com/model_authors' }
+
+    meta do
+      {
+        rating: 5,
+        favorite_count: 10
+      }
+    end
+
+    def blog
+      Blog.new(id: 999, name: 'Custom blog')
+    end
+  end
+  class CachingAuthorSerializer < AuthorSerializer
+    cache key: 'writer', only: [:first_name, :last_name], skip_digest: true
+  end
+
+  class CachingCommentSerializer < CommentSerializer
+    cache expires_in: 1.day, skip_digest: true
+  end
+
+  class CachingModelSerializer < ActiveModel::Serializer
+    cache key: 'model', expires_in: 0.1, skip_digest: true
+
+    attributes :id, :title, :body
+
+    belongs_to :blog, serializer: BlogSerializer
+    belongs_to :author, serializer: CachingAuthorSerializer
+    has_many :comments, serializer: CachingCommentSerializer
+
+    link(:model_authors) { 'https://example.com/model_authors' }
+
+    meta do
+      {
+        rating: 5,
+        favorite_count: 10
+      }
+    end
+
+    def blog
+      Blog.new(id: 999, name: 'Custom blog')
+    end
+  end
+end
 $VERBOSE = verbose

test/serializers/associations_test.rb

@@ -261,6 +261,30 @@ def false
 
           assert_equal(expected, hash)
         end
+
+        def test_associations_yield_reflections
+          model = ModelWithAssociations::Model.new(
+            id: 1337,
+            title: 'New Post',
+            blog: nil,
+            body: 'Body',
+            comments: (0..50).map { |i| ModelWithAssociations::Comment.new(id: i, body: 'ZOMG A COMMENT') },
+            author: ModelWithAssociations::Author.new(id: 42, first_name: 'Joao', last_name: 'Moura')
+          )
+          include_tree = ActiveModel::Serializer::IncludeTree.from_include_args('*')
+
+          associations = []
+          ModelWithAssociations::ModelSerializer.new(model).associations(include_tree).each do |association|
+            associations << association
+          end
+          assert_equal [:author, :blog, :comments], associations.map(&:key).sort
+
+          associations = []
+          ModelWithAssociations::CachingModelSerializer.new(model).associations(include_tree).each do |association|
+            associations << association
+          end
+          assert_equal [:author, :blog, :comments], associations.map(&:key).sort
+        end
       end
     end
   end