Updated user model that belongs to Contact, who has the EmailAddress association

user.rb

# app/models/user.rb
class User
  belongs_to :contact
  
  # This is optional
  has_many :email_addresses, through: :contact
  
  # So we can create the contact association when creating a User
  accepts_nested_attributes_for :contact
  after_initialize :add_contact
  
  # Create new blank contact on new record initialize.
  # This makes it so a blank Contact is attached when when
  # we create a new User
  def add_contact
    self.contact ||= Contact.new if self.new_record?
  end
  
  # ...
  # Then below are the same devise overrides from the
  # user.rb shown above. There are no changes to them.
end