class Shoulda::Matchers::ActiveModel::OnlyIntegerMatcher

def allowed_types
  'integer'
end

def failure_message_for_should
  @disallow_value_matcher.failure_message_for_should
end

def initialize(attribute)
  @attribute = attribute
  @disallow_value_matcher = DisallowValueMatcher.new(NON_INTEGER_VALUE).
    for(attribute).
    with_message(:not_an_integer)
end

def matches?(subject)
  @disallow_value_matcher.matches?(subject)
end

def with_message(message)
  @disallow_value_matcher.with_message(message)
  self
end