It seems that lazy_load_data: true does not work as expected for multilevel and polymorphic or STI relationships defined more than once. #246

class ApplicationSerializer
  include JSONAPI::Serializer

  def self.has_many(name, options = {}, &block)
    super(name, options.merge(lazy_load_data: true), &block)
  end

  def self.has_one(name, options = {}, &block)
    super(name, options.merge(lazy_load_data: true), &block)
  end

  def self.belongs_to(name, options = {}, &block)
    super(name, options.merge(lazy_load_data: true), &block)
  end

  def self.has_and_belongs_to_many(name, options = {}, &block)
    super(name, options.merge(lazy_load_data: true), &block)
  end
end

class ASerializer < ApplicationSerializer
  has_many :b
end
class BSerializer < ApplicationSerializer
  belongs_to :c, polymorphic: true
end

{
  "data"=>{
    ...
  },
  "included"=>
  [
    ...
    {
      ...
    },
    ...
  ],l
  "relationships"=> {
    "c"=>{
      data => {
        ...
      }
    }
  }
},
"meta"=>{"total-count"=>1},
"links"=> {
  "self"=> "http://link.com/path",
  "current"=> "http://link.com/path",
}

{
  "data"=>{
    ...
  },
  "included"=>
  [
    ...
    {
      ...
    },
    ...
  ],l
  "relationships"=> {
    "c"=>{
      data => {}
    }
  }
},
"meta"=>{"total-count"=>1},
"links"=> {
  "self"=> "http://link.com/path",
  "current"=> "http://link.com/path",
}