module ActiveRecord::Associations::Builder
  class SingularAssociation < Association #:nodoc:
    def valid_options
      super + [:remote, :dependent, :counter_cache, :primary_key, :inverse_of]
    end

    def constructable?
      true
    end

    def define_accessors
      super
      define_constructors if constructable?
    end

    def define_constructors
      name = self.name

      mixin.redefine_method("build_#{name}") do |*params, &block|
        association(name).build(*params, &block)
      end

      mixin.redefine_method("create_#{name}") do |*params, &block|
        association(name).create(*params, &block)
      end

      mixin.redefine_method("create_#{name}!") do |*params, &block|
        association(name).create!(*params, &block)
      end
    end
  end
end