Module: Vindicator

Defined in:
lib/vindicator.rb,
lib/vindicator/version.rb

Constant Summary collapse

VERSION = 
"0.1.0"

Class Method Summary collapse

Class Method Details

.valid_vin?(vin) ⇒ Boolean

Example valid_vin?(‘1GNEC233X9R191831’)

Returns:

  • (Boolean) 


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# File 'lib/vindicator.rb', line 9

def self.valid_vin?(vin)
  # I, O, and Q are not valid letters in a VIN. A valid VIN is exactly 17 characters in length
  vin = vin.to_s.downcase.gsub(/(i|o|q|\W|_)/i,'').split('')
  return false if vin.size != 17

  # The 9th character is the check digit
  check_digit = vin[8]

  # Set up the numeric values for alpha characters and the weight for each position in the VIN
  alpha_values = {'a' => 1, 'b' => 2, 'c' => 3, 'd' => 4, 'e' => 5, 'f' => 6, 'g' => 7, 'h' => 8,
                  'j' => 1, 'k' => 2, 'l' => 3, 'm' => 4, 'n' => 5,           'p' => 7,           'r' => 9,
                            's' => 2, 't' => 3, 'u' => 4, 'v' => 5, 'w' => 6, 'x' => 7, 'y' => 8, 'z' => 9}
  weight = [8,7,6,5,4,3,2,10,0,9,8,7,6,5,4,3,2]

  total = 0
  vin.each_with_index do |num,index|
    next if index == 8 # skip the check digit
    if num =~ /\d/
      total += num.to_i * weight[index]
    elsif num =~ /[a-z]/
      total += alpha_values[num] * weight[index]
    end
  end

  # The total divided my the remainder should be the same as the check digit.
  # The check digit should be x if the remainder is 10
  remainder = total % 11
  remainder = 'x' if remainder == 10
  check_digit.to_s == remainder.to_s
end