Use a dynamic module to include the writing methods that are generated from using belongs_to

[doliveirakn]

Prior to this, if we have something like

class Link < ActiveRecord::Base
  include PolymorphicIntegerType::Extensions

  belongs_to :source, polymorphic: true, integer_type: true
  belongs_to :target, polymorphic: true, integer_type: true

  def source=(val)
    super(val)
  end

  def source_type=(val)
    super(val)
  end
end

the source= will override the method defined by the belongs_to and what will end up happening is that the source_type will not end up being created properly.

By created an anonymous module, we can prepend it to the class and then the super behaviour will work as expected.

[doliveirakn]

This line is also new.

Previously, we checked klass.to_s, then klass.base_class.to_s, then klass.base_class.sti_name. This ensures that we check klass.sti_name before we move to the base class.

[doliveirakn]

mapping is a a local variable in the context of the belongs_to method. It was captured in the context of the dynamic methods. We have the ability to access the mapping through a class variable, so we can use that method instead of capturing the local variable.