LG-1411 Add error message when attempting to add email you already have

app/forms/add_user_email_form.rb

@@ -43,7 +43,7 @@ def new_email_address(params)
   attr_reader :success, :email_address
 
   def valid_form?
-    @allow && valid? && !email_taken?
+    @allow && valid?
   end
 
   def process_successful_submission
@@ -54,7 +54,6 @@ def process_successful_submission
 
   def extra_analytics_attributes
     {
-      email_already_exists: email_taken?,
       user_id: existing_user.uuid,
       domain_name: email&.split('@')&.last,
     }.merge(@recaptcha_h)

app/validators/form_add_email_validator.rb

@@ -27,6 +27,7 @@ def downcase_and_strip
 
   def email_is_available_to_user
     email_address = EmailAddress.find_with_email(email)
-    @email_taken = true if email_address&.user_id == @user.id
+    return unless email_address&.user_id == @user.id
+    errors.add(:email, I18n.t('email_addresses.add.duplicate'))
   end
 end

config/locales/email_addresses/en.yml

@@ -1,6 +1,8 @@
 ---
 en:
   email_addresses:
+    add:
+      duplicate: This email address is already registered to your account.
     delete:
       confirm: Are you sure you want to delete %{email}?
       failure: Unable to delete this email address.

config/locales/email_addresses/es.yml

@@ -1,6 +1,8 @@
 ---
 es:
   email_addresses:
+    add:
+      duplicate: Esta dirección de correo electrónico ya está registrada en su cuenta.
     delete:
       confirm: "¿Estas seguro que quieres borrarlo %{email}?"
       failure: No se puede eliminar esta dirección de correo electrónico.

config/locales/email_addresses/fr.yml

@@ -1,6 +1,8 @@
 ---
 fr:
   email_addresses:
+    add:
+      duplicate: Cette adresse e-mail est déjà enregistrée sur votre compte.
     delete:
       confirm: Etes-vous sûr que vous voulez supprimer %{email}?
       failure: Impossible de supprimer cette adresse email.

spec/features/multiple_emails/add_email_spec.rb

@@ -133,6 +133,21 @@
       expect(page).to have_current_path(add_email_path)
     end
 
+    it 'stays on form and gives an error message when adding an email already on the account' do
+      user = create(:user, :signed_up)
+      sign_in_and_2fa_user(user)
+      visit account_path
+      click_link t('account.index.email_add')
+
+      expect(page).to have_current_path(add_email_path)
+
+      fill_in 'Email', with: user.email_addresses.first.email
+      click_button t('forms.buttons.submit.default')
+
+      expect(page).to have_current_path(add_email_path)
+      expect(page).to have_content(I18n.t('email_addresses.add.duplicate'))
+    end
+
     it 'does not show verify screen without an email in session from add email' do
       user = create(:user, :signed_up)
       sign_in_and_2fa_user(user)