feat(User.validation): validates email when env var is present

app/models/user.rb

@@ -33,10 +33,15 @@ class User < ApplicationRecord
   accepts_nested_attributes_for :france_connect_information
 
   default_scope { eager_load(:instructeur, :administrateur, :expert) }
-  before_validation -> { sanitize_email(:email) }
 
+  before_validation -> { sanitize_email(:email) }
   validate :does_not_merge_on_self, if: :requested_merge_into_id_changed?
 
+  with_options if: :elligible_to_new_validation? do
+    before_validation :remove_devise_email_validator
+    validates :email, strict_email: true
+  end
+
   def validate_password_complexity?
     administrateur?
   end
@@ -268,4 +273,18 @@ class User < ApplicationRecord
   def link_invites!
     Invite.where(email: email).update_all(user_id: id)
   end
+
+  def elligible_to_new_validation?
+    StrictEmailValidator.elligible_to_new_validation?(self)
+  end
+
+  def remove_devise_email_validator
+    _validators[:email]&.reject! { _1.is_a?(ActiveModel::Validations::FormatValidator) }
+    _validate_callbacks.each do |callback|
+      next if !callback.filter.is_a?(ActiveModel::Validations::FormatValidator)
+      next if !callback.filter.attributes.include? :email
+
+      callback.filter.attributes.delete(:email)
+    end
+  end
 end

app/validators/strict_email_validator.rb

@@ -6,14 +6,22 @@ class StrictEmailValidator < ActiveModel::EachValidator
   REGEXP = /\A[^@\s]+@[^@\s\.]+\.[^@\s]{2,}\z/
 
   def validate_each(record, attribute, value)
-    if value.present? && !REGEXP.match?(value)
-      record.errors.add(attribute, :format)
+    if value.present? && !regexp_for(record).match?(value)
+      record.errors.add(attribute, :invalid_email_format)
+    end
+  end
+
+  def regexp_for(record)
+    if StrictEmailValidator.elligible_to_new_validation?(record)
+      REGEXP
+    else
+      Devise.email_regexp
     end
   end
 
   def self.elligible_to_new_validation?(record)
     return false if !strict_validation_enabled?
-    return false if (record.created_at || Time.now) < date_since_strict_email_validation
+    return false if (record.created_at || Time.zone.now) < date_since_strict_email_validation
     true
   end
 
@@ -26,6 +34,4 @@ class StrictEmailValidator < ActiveModel::EachValidator
   rescue
     DateTime.new(1789, 5, 5, 0, 0) # french revolution, ds was not yet launched
   end
-
-
 end