Class: BankCard::Validations::LuhnValidator

Inherits:
ActiveModel::EachValidator
  • Object
show all
Defined in:
lib/bank_card/validations/luhn_validator.rb

Instance Method Summary collapse

Instance Method Details

#validate_each(record, attribute, value) ⇒ Object 



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# File 'lib/bank_card/validations/luhn_validator.rb', line 4

def validate_each(record, attribute, value)
  relative_number = {'0' => 0, '1' => 2, '2' => 4, '3' => 6, '4' => 8, '5' => 1, '6' => 3, '7' => 5, '8' => 7, '9' => 9}

  sum = 0

  value.to_s.reverse.split("").each_with_index do |n, i|
  sum += (i % 2 == 0) ? n.to_i : relative_number[n]
  end

  unless sum % 10 == 0
    record.errors.add(attribute, :invalid, options)
  end
end