Send Devise emails triggered from the 'Email' model asynchronously

This change sends Devise emails triggered from the
'Email' model asynchronously

app/models/concerns/async_devise_email.rb

+# frozen_string_literal: true
+
+module AsyncDeviseEmail
+  extend ActiveSupport::Concern
+
+  private
+
+  # Added according to https://github.com/plataformatec/devise/blob/7df57d5081f9884849ca15e4fde179ef164a575f/README.md#activejob-integration
+  def send_devise_notification(notification, *args)
+    return true unless can?(:receive_notifications)
+
+    devise_mailer.__send__(notification, self, *args).deliver_later # rubocop:disable GitlabSecurity/PublicSend
+  end
+end

app/models/email.rb

@@ -15,9 +15,14 @@ class Email < ApplicationRecord
   after_commit :update_invalid_gpg_signatures, if: -> { previous_changes.key?('confirmed_at') }
 
   devise :confirmable
+
+  # This module adds async behaviour to Devise emails
+  # and should be added after Devise modules are initialized.
+  include AsyncDeviseEmail
+
   self.reconfirmable = false # currently email can't be changed, no need to reconfirm
 
-  delegate :username, to: :user
+  delegate :username, :can?, to: :user
 
   def email=(value)
     write_attribute(:email, value.downcase.strip)

app/models/user.rb

@@ -58,6 +58,10 @@ class User < ApplicationRecord
   devise :lockable, :recoverable, :rememberable, :trackable,
          :validatable, :omniauthable, :confirmable, :registerable
 
+  # This module adds async behaviour to Devise emails
+  # and should be added after Devise modules are initialized.
+  include AsyncDeviseEmail
+
   BLOCKED_MESSAGE = "Your account has been blocked. Please contact your GitLab " \
                     "administrator if you think this is an error."
   LOGIN_FORBIDDEN = "Your account does not have the required permission to login. Please contact your GitLab " \
@@ -1746,13 +1750,6 @@ class User < ApplicationRecord
     ApplicationSetting.current_without_cache&.usage_stats_set_by_user_id == self.id
   end
 
-  # Added according to https://github.com/plataformatec/devise/blob/7df57d5081f9884849ca15e4fde179ef164a575f/README.md#activejob-integration
-  def send_devise_notification(notification, *args)
-    return true unless can?(:receive_notifications)
-
-    devise_mailer.__send__(notification, self, *args).deliver_later # rubocop:disable GitlabSecurity/PublicSend
-  end
-
   def ensure_user_rights_and_limits
     if external?
       self.can_create_group = false

changelogs/unreleased/async-secondary-email-devise-mailers.yml

+---
+title: Send Devise emails triggered from the 'Email' model asynchronously
+merge_request: 32286
+author:
+type: fixed

spec/controllers/profiles/emails_controller_spec.rb

@@ -9,6 +9,12 @@ describe Profiles::EmailsController do
     sign_in(user)
   end
 
+  around do |example|
+    perform_enqueued_jobs do
+      example.run
+    end
+  end
+
   describe '#create' do
     context 'when email address is valid' do
       let(:email_params) { { email: "add_email@example.com" } }

spec/features/profiles/emails_spec.rb

@@ -67,7 +67,7 @@ describe 'Profile > Emails' do
     email = user.emails.create(email: 'my@email.com')
     visit profile_emails_path
 
-    expect { click_link("Resend confirmation email") }.to change { ActionMailer::Base.deliveries.size }
+    expect { click_link("Resend confirmation email") }.to have_enqueued_job.on_queue('mailers')
     expect(page).to have_content("Confirmation email sent to #{email.email}")
   end
 

spec/models/email_spec.rb

@@ -3,6 +3,12 @@
 require 'spec_helper'
 
 describe Email do
+  describe 'modules' do
+    subject { described_class }
+
+    it { is_expected.to include_module(AsyncDeviseEmail) }
+  end
+
   describe 'validations' do
     it_behaves_like 'an object with RFC3696 compliant email-formated attributes', :email do
       subject { build(:email) }
@@ -45,4 +51,16 @@ describe Email do
       expect(build(:email, user: user).username).to eq user.username
     end
   end
+
+  describe 'Devise emails' do
+    let!(:user) { create(:user) }
+
+    describe 'behaviour' do
+      it 'sends emails asynchronously' do
+        expect do
+          user.emails.create!(email: 'hello@hello.com')
+        end.to have_enqueued_job.on_queue('mailers')
+      end
+    end
+  end
 end

spec/models/user_spec.rb

@@ -17,6 +17,7 @@ describe User do
     it { is_expected.to include_module(Sortable) }
     it { is_expected.to include_module(TokenAuthenticatable) }
     it { is_expected.to include_module(BlocksJsonSerialization) }
+    it { is_expected.to include_module(AsyncDeviseEmail) }
   end
 
   describe 'delegations' do
@@ -165,6 +166,18 @@ describe User do
     end
   end
 
+  describe 'Devise emails' do
+    let!(:user) { create(:user) }
+
+    describe 'behaviour' do
+      it 'sends emails asynchronously' do
+        expect do
+          user.update!(email: 'hello@hello.com')
+        end.to have_enqueued_job.on_queue('mailers').exactly(:twice)
+      end
+    end
+  end
+
   describe 'validations' do
     describe 'password' do
       let!(:user) { create(:user) }

spec/services/emails/confirm_service_spec.rb

@@ -8,10 +8,10 @@ describe Emails::ConfirmService do
   subject(:service) { described_class.new(user) }
 
   describe '#execute' do
-    it 'sends a confirmation email again' do
+    it 'enqueues a background job to send confirmation email again' do
       email = user.emails.create(email: 'new@email.com')
-      mail  = service.execute(email)
-      expect(mail.subject).to eq('Confirmation instructions')
+
+      expect { service.execute(email) }.to have_enqueued_job.on_queue('mailers')
     end
   end
 end