NoMethodError in allow_listed? and disposable_domain? when address is unparseable

[kwent]

Description

allow_listed? and disposable_domain? raise NoMethodError: undefined method 'domain' for nil when called on an unparseable email address (e.g. "><test>").

Root cause

When Mail::Address.new raises a ParseError, the @address instance variable remains nil and @parse_error is set to true. However, allow_listed? and disposable_domain? access address.domain without first checking valid?:

# These methods don't guard — they crash on nil @address:
def allow_listed?
  domain_is_in?(address.domain, ValidEmail2.allow_list)  # address is nil → NoMethodError
end

def disposable_domain?
  domain_is_in?(address.domain, ValidEmail2.disposable_emails)  # same issue
end

# These methods DO guard correctly:
def deny_listed?
  valid? && domain_is_in?(address.domain, ValidEmail2.deny_list)  # ✅
end

def valid_mx?
  return false unless valid?  # ✅
  # ...
end

Reproduction

require 'valid_email2'
require 'valid_email2/address'

a = ValidEmail2::Address.new('"><test>')
a.valid?        # => false (correct)
a.allow_listed? # => NoMethodError: undefined method 'domain' for nil

Expected behavior

allow_listed? and disposable_domain? should return false for unparseable addresses, consistent with deny_listed? and valid_mx?.

Suggested fix

Add a valid? guard to both methods:

def allow_listed?
  valid? && domain_is_in?(address.domain, ValidEmail2.allow_list)
end

def disposable_domain?
  valid? && domain_is_in?(address.domain, ValidEmail2.disposable_emails)
end

Environment

• valid_email2 7.0.15
• Ruby 4.0.5
• mail gem 2.9.0