module ThoughtBot::Shoulda::ActiveRecord::Macros

def should_ensure_length_is(attribute, length, opts = {})


should_ensure_length_is :ssn, 9
Example:

Regexp or string. Default = I18n.translate('activerecord.errors.messages.wrong_length') % length
* :message - value the test expects to find in errors.on(:attribute).
Options:

create a new instance to test against.
model being tested, then this method will use that. Otherwise, it will
If an instance variable has been created in the setup named after the

Ensures that the length of the attribute is exactly a certain length 
def should_ensure_length_is(attribute, length, opts = {})
  message = get_options!([opts], :message)
  message ||= default_error_message(:wrong_length, :count => length)
  klass = model_class
  should "not allow #{attribute} to be less than #{length} chars long" do
    min_value = "x" * (length - 1)
    assert_bad_value(klass, attribute, min_value, message)
  end
  should "not allow #{attribute} to be greater than #{length} chars long" do
    max_value = "x" * (length + 1)
    assert_bad_value(klass, attribute, max_value, message)
  end
  should "allow #{attribute} to be #{length} chars long" do
    valid_value = "x" * (length)
    assert_good_value(klass, attribute, valid_value, message)
  end
end