refactor: use email_validator gem instead of custom regex

- Add email_validator gem for Rails-native email validation
- Replace custom EMAIL_REGEX with gem's strict mode
- Single source of truth for email validation

Author: mroderick

Gemfile

@@ -18,6 +18,7 @@ gem 'csv' # LOCKED: csv was loaded from the standard library, but is not part of
 gem 'delayed_job'
 gem 'delayed_job_active_record'
 gem 'drb' # LOCKED: Added because of pry-remote
+gem 'email_validator'
 gem 'font_awesome5_rails'
 gem 'bootstrap', '~> 5'
 gem 'friendly_id'

Gemfile.lock

@@ -193,6 +193,8 @@ GEM
       dotenv (= 3.2.0)
       railties (>= 6.1)
     drb (2.2.3)
+    email_validator (2.2.4)
+      activemodel
     erb (6.0.2)
     erubi (1.13.1)
     execjs (2.10.1)
@@ -635,6 +637,7 @@ DEPENDENCIES
   delayed_job_active_record
   dotenv-rails
   drb
+  email_validator
   fabrication
   faker
   faraday

app/helpers/email_header_helper.rb

@@ -1,6 +1,4 @@
 module EmailHeaderHelper
-  EMAIL_REGEX = /\A[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\.[A-Za-z]{2,}\z/
-
   private
 
   def mail_args(member, subject, from_email = 'meetings@codebar.io', cc = '', bcc = '')
@@ -14,7 +12,7 @@ def mail_args(member, subject, from_email = 'meetings@codebar.io', cc = '', bcc
   end
 
   def invalid_email?(email, member_id)
-    return false if email.present? && email.match?(EMAIL_REGEX)
+    return false if EmailValidator.valid?(email, mode: :strict)
 
     Rails.logger.warn("[EmailHeaderHelper] Invalid email for member_id=#{member_id}: #{email}")
     true

app/models/member.rb

@@ -23,12 +23,10 @@ class Member < ApplicationRecord
   has_many :announcements, -> { distinct }, through: :groups
   has_many :meeting_invitations
 
-  EMAIL_REGEX = /\A[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\.[A-Za-z]{2,}\z/
-
   validates :auth_services, presence: true
   validates :name, :surname, :email, :about_you, presence: true, if: :can_log_in?
   validates :email, uniqueness: true
-  validates :email, format: { with: EMAIL_REGEX }, if: :can_log_in?
+  validates :email, email: { mode: :strict }, if: :can_log_in?
   validates :about_you, length: { maximum: 255 }
 
   DIETARY_RESTRICTIONS = %w[vegan vegetarian pescetarian halal gluten_free dairy_free other].freeze