Support ActiveRecord setting id columns on belong_to relationships

enhanced_association_id_setter.rb

module EnhancedAssociationIdSetter
  extend ActiveSupport::Concern

  module ClassMethods
    def belongs_to(name, scope = nil, **options)
      result = super
      build_assocation_id_setter_for(name)
      result
    end

    def build_assocation_id_setter_for(assocation)
      reflection = reflections[assocation.to_s]

      raise "Unable to find #{assocation} for #{model_name.class_name}" unless reflection

      id_column = reflection.foreign_key
      association_klass = reflection.class_name

      class_eval <<~RUBY, __FILE__, __LINE__ + 1
        def #{id_column}=(value)
          new_value = value.is_a?(#{association_klass}) ? value.id : value
          self[:#{id_column.to_sym}] = new_value
        end
      RUBY
    end
  end
end