class Shoulda::Matchers::ActiveModel::AllowValueMatcher::AttributeSetters

def does_not_match?(tuple)
  !tuple.attribute_setter.set!
end

def each(&block)
  tuples.each(&block)
end

def first_failing
  tuples.detect(&method(:does_not_match?))
end

def initialize(allow_value_matcher, values)
  @tuples = values.map do |attribute_name, value|
    AttributeSetterAndValidator.new(
      allow_value_matcher,
      attribute_name,
      value,
    )
  end
end