Validation of IBAN, ISBN, ISSN, UESRP, NER and VATIN numbers

validations.rb

# SPDX-License-Identifier: MIT

## Copyright (C) 2010 Przemyslaw Pawelczyk <przemoc@gmail.com>
##
## This script is licensed under the terms of the MIT license.
## https://opensource.org/licenses/MIT

module Validations # version 0.1
  # International Bank Account Number
  def iban?
    unless /\A[A-Z]{2}\d{2} ?[A-Z\d]{4}( ?\d{4}){1,} ?\d{1,4}\z/ === self
      return false
    end
    iban = self.gsub( / /, '' )
    iban = ( iban[4..-1] + iban[0..3] ).gsub( /[A-Z]/ ) { |c| ( c[0] - 55 ).to_s }
    iban.to_i % 97 == 1
  end

  # International Standard Book Number
  def isbn?
    unless [13,17].include?( self.size ) and /\A((978|979)-)?\d+-\d+-\d+-[X\d]\z/ === self
      return false
    end
    isbn = self.gsub( '-', '' )
    r = 0
    case isbn.size
    when 10
      0.upto( 8 ) { |i| r += isbn[i,1].to_i * [10,9,8,7,6,5,4,3,2][i] }
      r = ( 11 - r  % 11 ) % 11
      r = ( r < 10 ) ? r.to_s : 'X'
    when 13
      0.upto( 11 ) { |i| r += isbn[i,1].to_i * [1,3][i % 2] }
      r = ( ( ( 10 - r ) % 10 ) % 10 ).to_s
    end
    isbn[-1,1] == r
  end

  # International Standard Serial Number
  def issn?
    unless self.size == 9 and /\A\d{4}\-\d{3}[X\d]\z/ === self
      return false
    end
    issn = self.gsub( '-', '' )
    r = 0
    0.upto( 6 ) { |i| r += issn[i,1].to_i * [8,7,6,5,4,3,2][i] }
    r = ( 11 - r % 11 ) % 11
    issn[-1,1] == ( ( r < 10 ) ? r.to_s : 'X' )
  end

  # Polish: Powszechny Elektroniczny System Ewidencji Ludności
  # Universal Electronic System for Registration of the Population
  def pesel?
    unless self.size == 11 and /\A\d+\z/ === self
      return false
    end
    r = 0
    0.upto( 10 ) { |i| r += self[i,1].to_i * [1,3,7,9,1,3,7,9,1,3,1][i] }
    r % 10 == 0
  end

  # Polish: Rejestr Gospodarki Narodowej
  # National Economy Register
  def regon?
    unless [9,14].include?( self.size ) and /\A\d+\z/ === self
      return false
    end
    r = 0
    case self.size
    when 9
      0.upto( 7 ) { |i| r += self[i,1].to_i * [8,9,2,3,4,5,6,7][i] }
    when 14
      0.upto( 12 ) { |i| r += self[i,1].to_i * [2,4,8,5,0,9,7,3,6,1,2,4,8][i] }
    end
    ( r % 11 ) % 10 == self[-1,1].to_i
  end

  # Value Added Tax Identification Number
  # uses VIES - VAT Information Exchange System
  def vatin?
    require 'net/http'
    unless self.size <= 20 && /\A[A-Z]{2}/ === self
      return false
    end
    vat = self.gsub( /[ \-]/, '' )
    req = Net::HTTP::Post.new( '/taxation_customs/vies/viesquer.do' )
    req.set_form_data( { 'iso' => vat[0..1], 'vat' => vat[2..-1] } )
    res = Net::HTTP.start( 'ec.europa.eu' ) { |q| q.request( req ) }
    res.body.include?( 'Yes, valid VAT number' )
  end
end

class String
  include Validations
end

commit 4b58f417039738016c6d9e542aaa381ee61c036c
Author: Przemyslaw Pawelczyk <przemoc@gmail.com>
Date:   2018-02-06 15:22:07 +0100

    validations.rb: Add copyright notice and MIT license notice.

commit 7f80078b4a95949123b2c8a941b18426d9ddbc46
Author: Przemyslaw Pawelczyk <przemoc@gmail.com>
Date:   2018-02-06 15:22:50 +0100

    Add SPDX License Identifier.

    The Software Package Data Exchange (SPDX) is a good initiative, it has
    matured over time and deserves accelerated adoption in open-source.

    https://spdx.org/learn
    https://spdx.org/using-spdx
    https://spdx.org/license-list