pi_spec.rb

require "minitest/autorun"

module PI
  extend self

  def call(str)
    return mask_email(str) if str =~ /@/
    mask_phone(str)
  end

  def mask_email(str)
    email_parts = str.downcase.scan(/(^\w{1})(\w*)(.+)(@)(\w+)(.)(\w+)/).flatten
    email_parts[1] = "*" * 5
    email_parts.join
  end

  def mask_phone(str)
    normalize_phone= str.gsub(/[\(|\)|\-]/, '')
    if normalize_phone.size == 10
      phone_parts = normalize_phone.scan(/(\d{3})(\d{3})(\d{4})/).flatten
      phone_parts[0] = replace_number_with_asterisk_for(phone_parts[0])
      phone_parts[1] = replace_number_with_asterisk_for(phone_parts[1])
      phone_parts.join('-')
    else
      phone_parts = normalize_phone.scan(/(\d{2})(\d{3})(\d{3})(\d{4})/).flatten
      0.upto(2).each do |idx|
        phone_parts[idx] = replace_number_with_asterisk_for(phone_parts[idx])
      end
      "+#{phone_parts.join('-')}"
    end
  end

  def replace_number_with_asterisk_for(str)
    str.gsub(/./, '*')
  end
end

describe PI do
  describe "when passing emails" do
    it "replace all letters in the first name to asterisks and lowercase everything" do
      PI.("[email protected]").must_equal "n*****[email protected]"
      PI.("[email protected]").must_equal "l*****[email protected]"
      PI.("[email protected]").must_equal "a*****[email protected]"
    end

    it "masks phone numbers" do
      PI.("1(234)567-890").must_equal "***-***-7890"
      PI.("86-(10)12345678").must_equal "+**-***-***-5678"
    end
  end
end