Each resident in Japan is notified of his or her own Individual Number (a.k.a. "My Number") beginning in October 2015, and each company is given its own Corporate Number likewise.

This gem provides both My Number and Corporate Number validators which inspect the format and (optionally) the check digit.

Add this line to your application's Gemfile:

gem 'tsubaki'

And then execute:

$ bundle

Or install it yourself as:

$ gem install tsubaki

A My Number consists of 12 digits & the last digit is used as a check digit.

To validate the format of an attribute, add the following to your model:

# Verifies the format and its check digit with `strict` option:
validates :digits, my_number: { strict: true, allow_blank: true }

# Without strict option, it verifies only the length of the digits:
validates :digits, my_number: true

# Or if a My Number contains any dividers, specify it:
validates :digits, my_number: { strict: true, divider: '-' } # => 4652-8126-6333 should be valid

A Corporate Number consists of 13 digits & the first digit is used as a check digit.

To validate the format of an attribute, add the following to your model:

# Verifies the format and its check digit with `strict` option:
validates :digits, corporate_number: { strict: true, allow_blank: true }

# Without strict option, it verifies only the length of the digits:
validates :digits, corporate_number: true

# Or if a Corporate Number contains any dividers, specify it:
validates :digits, corporate_number: { strict: true, divider: '-' } # => 5-8356-7825-6246 should be valid

To ensure appropriate validations are specified, Tsubaki includes rspec matchers.

# In spec_helper.rb, you'll need to require the matchers:
require 'tsubaki/matchers'

# And include the module:
RSpec.configure do |config|
  config.include Tsubaki::Shoulda::Matchers
end

describe User do
  # For My Number validation
  it { should validate_my_number_of(:digits) }

  # To ensure options:
  it { should validate_my_number_of(:digits).strict.with_divider('-').allow_blank }
end

describe Company do
  # For Corporate Number validation
  it { should validate_corporate_number_of(:digits) }

  # To ensure options:
  it { should validate_corporate_number_of(:digits).strict.with_divider('-') }
end

You can obtain a random yet having valid check digit numbers. These are useful when creating dummy records.

Tsubaki::MyNumber.rand # => 765895492872
Tsubaki::CorporateNumber.rand # => 5868731863533

擬似マイナンバーくん demonstrates the random number generators.

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/kufu/tsubaki.

Everyone interacting in the tsubaki project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.

The gem is available as open source under the terms of the MIT License).