Class: MiniDefender::Rules::Luhn

Inherits:
MiniDefender::Rule show all
Defined in:
lib/mini_defender/rules/luhn.rb

Direct Known Subclasses

CreditCard, NationalId

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from MiniDefender::Rule

#active?, available?, #bails?, #default_value, #defaults?, #error_message, #excluded?, #force_coerce?, #implicit?, make, #priority, #stops?, #with_message

Class Method Details

.signature ⇒ Object 



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# File 'lib/mini_defender/rules/luhn.rb', line 4

def self.signature
  'luhn'
end

.valid_luhn?(value) ⇒ Boolean

Returns:



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# File 'lib/mini_defender/rules/luhn.rb', line 8

def self.valid_luhn?(value)
  value = value.to_s
  return false unless value.match?(/\A\d+\z/)

  double_sum = [0, 2, 4, 6, 8, 1, 3, 5, 7, 9]
  sum = 0

  value.to_i.digits.each_with_index do |digit, index|
    sum += index.even? ? digit : double_sum[digit]
  end

  sum % 10 === 0
end

Instance Method Details

#coerce(value) ⇒ Object 



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# File 'lib/mini_defender/rules/luhn.rb', line 22

def coerce(value)
  value.to_s
end

#message(attribute, value, validator) ⇒ Object 



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# File 'lib/mini_defender/rules/luhn.rb', line 30

def message(attribute, value, validator)
  'The value must be a valid Luhn string.'
end

#passes?(attribute, value, validator) ⇒ Boolean

Returns:



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# File 'lib/mini_defender/rules/luhn.rb', line 26

def passes?(attribute, value, validator)
  value.is_a?(String) && self.class.valid_luhn?(value)
end