Sha256: e98413dc02900d471a33a1349d5458a15e47f4bbeb966d07bb9ac3dad87d5415
Contents?: true
Size: 1.07 KB
Versions: 396
Compression:
Stored size: 1.07 KB
Contents
module.exports = class Luhn
constructor: (number) ->
@checkDigit = number % 10
@addends = @calculateAddends(number)
@checksum = @calculateChecksum(@addends)
@valid = @determineIfValid(@checksum)
calculateAddends: (number) ->
numberAsString = "" + number + ""
numbers = numberAsString.split('')
addends = (@calculateAddend(i,numbers) for i in [0..numbers.length-1])
addends.reverse()
calculateAddend: (i,numbers) ->
index = numbers.length - 1 - i
currentAddend = parseInt(numbers[index])
if (i + 1) % 2 == 0
currentAddend = currentAddend * 2
if currentAddend > 10
currentAddend = currentAddend - 9
currentAddend
calculateChecksum: (numbers) ->
numbers.reduce (x,y) -> x + y
determineIfValid: (sum) ->
(sum % 10 == 0)
@create = (number) ->
finalNumber = number * 10
luhnNumber = new Luhn(finalNumber)
index = 0
while(!luhnNumber.valid)
finalNumber = number * 10 + index
luhnNumber = new Luhn(finalNumber)
break if luhnNumber.valid
index += 1
finalNumber
Version data entries
396 entries across 396 versions & 1 rubygems