Simple email validation micro gem

email_validator.gemspec

Gem::Specification.new do |s|
  s.name        = 'email_validator'
  s.version     = '0.1.0'
  s.platform    = Gem::Platform::RUBY
  s.author      = 'Betterplace Developers'
  s.email       = 'developers@betterplace.org'
  s.summary     = 'Simple email validation for rails'
  s.description = "Stay simple but don't interfere with `mail`"

  s.files         = ['email_validator.rb']
  s.require_path  = '.'
end

email_validator.rb

class EmailValidator < ActiveModel::EachValidator
  def validate_each(record, attribute, value)
    record.errors[attribute] << error_message unless valid?(value)
  end

  VALID_EMAIL_PATTERN = /
    \A\.?
    [a-z0-9\#$%&'*+\/=?^_`{|}~-]+
    (?:\.[a-z0-9\#$%&'*+\/=?^_`{|}~-]*)*
    @
    (?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+
    [a-z0-9]
    (?:[a-z0-9-]*[a-z0-9])?
    \z
  /ix

  def self.valid?(email)
    VALID_EMAIL_PATTERN.match?(email)
  end

  def valid?(email)
    VALID_EMAIL_PATTERN.match?(email)
  end

  private

  def error_message
    options[:message] || :invalid
  end
end