Add deliver_all_later to enqueue multiple emails at once

Author: fatkodima

actionmailer/CHANGELOG.md

@@ -1,2 +1,17 @@
+*   Add `deliver_all_later` to enqueue multiple emails at once.
+
+    ```ruby
+    user_emails = User.all.map { |user| Notifier.welcome(user) }
+    ActionMailer.deliver_all_later(user_emails)
+
+    # use a custom queue
+    ActionMailer.deliver_all_later(user_emails, queue: :my_queue)
+    ```
+
+    This can greatly reduce the number of round-trips to the queue datastore.
+    For queue adapters that do not implement the `enqueue_all` method, we
+    fall back to enqueuing email jobs indvidually.
+
+    *fatkodima*
 
 Please check [8-0-stable](https://github.com/rails/rails/blob/8-0-stable/actionmailer/CHANGELOG.md) for previous changes.

actionmailer/lib/action_mailer/message_delivery.rb

@@ -3,6 +3,38 @@
 require "delegate"
 
 module ActionMailer
+  class << self
+    # Enqueue many emails at once to be delivered through Active Job.
+    # When the individual job runs, it will send the email using +deliver_now+.
+    def deliver_all_later(*deliveries, **options)
+      _deliver_all_later("deliver_now", *deliveries, **options)
+    end
+
+    # Enqueue many emails at once to be delivered through Active Job.
+    # When the individual job runs, it will send the email using +deliver_now!+.
+    # That means that the message will be sent bypassing checking +perform_deliveries+
+    # and +raise_delivery_errors+, so use with caution.
+    def deliver_all_later!(*deliveries, **options)
+      _deliver_all_later("deliver_now!", *deliveries, **options)
+    end
+
+    private
+      def _deliver_all_later(delivery_method, *deliveries, **options)
+        deliveries.flatten!
+
+        jobs = deliveries.map do |delivery|
+          mailer_class = delivery.mailer_class
+          delivery_job = mailer_class.delivery_job
+
+          delivery_job
+            .new(mailer_class.name, delivery.action.to_s, delivery_method, params: delivery.params, args: delivery.args)
+            .set(options)
+        end
+
+        ActiveJob.perform_all_later(jobs)
+      end
+  end
+
   # = Action Mailer \MessageDelivery
   #
   # The +ActionMailer::MessageDelivery+ class is used by
@@ -17,6 +49,8 @@ module ActionMailer
   #   Notifier.welcome(User.first).deliver_later # enqueue email delivery as a job through Active Job
   #   Notifier.welcome(User.first).message       # a Mail::Message object
   class MessageDelivery < Delegator
+    attr_reader :mailer_class, :action, :params, :args # :nodoc:
+
     def initialize(mailer_class, action, *args) # :nodoc:
       @mailer_class, @action, @args = mailer_class, action, args
 

actionmailer/test/message_delivery_test.rb

@@ -2,7 +2,9 @@
 
 require "abstract_unit"
 require "active_job"
+require "mailers/base_mailer"
 require "mailers/delayed_mailer"
+require "mailers/params_mailer"
 
 class MessageDeliveryTest < ActiveSupport::TestCase
   include ActiveJob::TestHelper
@@ -136,6 +138,67 @@ class DummyJob < ActionMailer::MailDeliveryJob; end
     end
   end
 
+  test "deliver_all_later enqueues multiple deliveries" do
+    mail1 = DelayedMailer.test_message(1)
+    mail2 = DelayedMailer.test_kwargs(argument: 1)
+
+    assert_performed_with(job: ActionMailer::MailDeliveryJob, args: ["DelayedMailer", "test_message", "deliver_now", params: nil, args: [1]]) do
+      assert_performed_with(job: ActionMailer::MailDeliveryJob, args: ["DelayedMailer", "test_kwargs", "deliver_now", params: nil, args: [argument: 1]]) do
+        ActionMailer.deliver_all_later(mail1, mail2)
+      end
+    end
+  end
+
+  test "deliver_all_later! enqueues multiple deliveries" do
+    mail1 = DelayedMailer.test_message(1)
+    mail2 = DelayedMailer.test_kwargs(argument: 1)
+
+    assert_performed_with(job: ActionMailer::MailDeliveryJob, args: ["DelayedMailer", "test_message", "deliver_now!", params: nil, args: [1]]) do
+      assert_performed_with(job: ActionMailer::MailDeliveryJob, args: ["DelayedMailer", "test_kwargs", "deliver_now!", params: nil, args: [argument: 1]]) do
+        ActionMailer.deliver_all_later!(mail1, mail2)
+      end
+    end
+  end
+
+  test "deliver_all_later enqueues multiple deliveries with correct jobs" do
+    old_delivery_job = BaseMailer.delivery_job
+    BaseMailer.delivery_job = DummyJob
+
+    mail1 = DelayedMailer.test_message
+    mail2 = BaseMailer.welcome
+
+    assert_performed_with(job: ActionMailer::MailDeliveryJob, args: ["DelayedMailer", "test_message", "deliver_now", params: nil, args: []]) do
+      assert_performed_with(job: DummyJob, args: ["BaseMailer", "welcome", "deliver_now", params: nil, args: []]) do
+        ActionMailer.deliver_all_later(mail1, mail2)
+      end
+    end
+  ensure
+    BaseMailer.delivery_job = old_delivery_job
+  end
+
+  test "deliver_all_later enqueues multiple deliveries with custom options" do
+    mail1 = DelayedMailer.test_message(1)
+    mail2 = DelayedMailer.test_message(2)
+
+    assert_performed_with(job: ActionMailer::MailDeliveryJob, args: ["DelayedMailer", "test_message", "deliver_now", params: nil, args: [1]], queue: "another_queue") do
+      assert_performed_with(job: ActionMailer::MailDeliveryJob, args: ["DelayedMailer", "test_message", "deliver_now", params: nil, args: [2]], queue: "another_queue") do
+        ActionMailer.deliver_all_later(mail1, mail2, queue: :another_queue)
+      end
+    end
+  end
+
+  test "deliver_all_later enqueues parameterized emails" do
+    mail1 = DelayedMailer.test_message(1)
+    mail2 = ParamsMailer.with(inviter: "[email protected]", invitee: "[email protected]").invitation
+
+    assert_performed_with(job: ActionMailer::MailDeliveryJob, args: ["DelayedMailer", "test_message", "deliver_now", params: nil, args: [1]]) do
+      assert_performed_with(job: ActionMailer::MailDeliveryJob,
+                            args: ["ParamsMailer", "invitation", "deliver_now", args: [], params: { inviter: "[email protected]", invitee: "[email protected]" }]) do
+        ActionMailer.deliver_all_later(mail1, mail2)
+      end
+    end
+  end
+
   test "job delegates error handling to mailer" do
     # Superclass not rescued by mailer's rescue_from RuntimeError
     message = DelayedMailer.test_raise("StandardError")