Ruby class for validating ORCID formats and checksums

LICENSE

The MIT License (MIT)

Copyright (c) 2018 Arfon Smith

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

orcid_validator.rb

class String
  def numeric?
    Float(self) != nil rescue false
  end
end

class OrcidValidator
  attr_reader :orcid

  def initialize(orcid)
    @orcid = orcid.strip
  end

  # Returns true or false
  def validate
    check_structure
    check_length
    check_chars

    if checksum_char == "X" || checksum_char == "x"
      return checksum == 10
    else
      return checksum == checksum_char.to_i
    end
  end

  def packed_orcid
    orcid.gsub('-', '')
  end

  # Returns the last character of the string
  def checksum_char
    packed_orcid[-1]
  end

  def first_11
    packed_orcid.chop
  end

  def check_structure
    groups = orcid.split('-')
    warn("ORCID looks malformed") unless groups.size == 4
  end

  def check_length
    warn("ORCID looks to be the wrong length") unless packed_orcid.length == 16
  end

  def check_chars
    first_11.each_char do |c|
      warn("Invalid ORDIC digit (#{c})") unless c.numeric?
    end
  end

  # https://support.orcid.org/knowledgebase/articles/116780-structure-of-the-orcid-identifier
  def checksum
    total = 0
    first_11.each_char do |c|
      total = (total + c.to_i) * 2
    end

    remainder = total % 11
    result = (12 - remainder) % 11

    return result
  end
end


p OrcidValidator.new("0000-0002-3957-2474").validate
# true

p OrcidValidator.new("0000-0002-3957-247X").validate
# false

p OrcidValidator.new("0000-0002-3957-247").validate
# ORCID looks to be the wrong length
# false

p OrcidValidator.new("0000-0002-3957-24XX").validate
# Invalid ORDIC digit (X)
# false

p OrcidValidator.new("0000000239572474").validate
# ORCID looks malformed
# true