feat(user): block unverified_email from being sent

app/lib/balancer_delivery_method.rb

@@ -14,6 +14,7 @@
 #
 # Be sure to restart your server when you modify this file.
 class BalancerDeliveryMethod
+  BYPASS_UNVERIFIED_MAIL_PROTECTION = 'BYPASS_UNVERIFIED_MAIL_PROTECTION'.freeze
   FORCE_DELIVERY_METHOD_HEADER = 'X-deliver-with'
   # Allows configuring the random number generator used for selecting a delivery method,
   # mostly for testing purposes.
@@ -24,6 +25,8 @@ class BalancerDeliveryMethod
   end
 
   def deliver!(mail)
+    return if prevent_delivery?(mail)
+
     balanced_delivery_method = delivery_method(mail)
     ApplicationMailer.wrap_delivery_behavior(mail, balanced_delivery_method)
 
@@ -40,6 +43,18 @@ class BalancerDeliveryMethod
 
   private
 
+  def prevent_delivery?(mail)
+    return false if mail[BYPASS_UNVERIFIED_MAIL_PROTECTION].present?
+
+    user = User.find_by(email: mail.to.first)
+    return user.unverified_email? if user.present?
+
+    individual = Individual.find_by(email: mail.to.first)
+    return individual.unverified_email? if individual.present?
+
+    true
+  end
+
   def force_delivery_method?(mail)
     @delivery_methods.keys.map(&:to_s).include?(mail[FORCE_DELIVERY_METHOD_HEADER]&.value)
   end

app/models/individual.rb

@@ -29,4 +29,6 @@ class Individual < ApplicationRecord
       gender: fc_information.gender == 'female' ? GENDER_FEMALE : GENDER_MALE
     )
   end
+
+  def unverified_email? = !email_verified_at?
 end

app/models/user.rb

@@ -267,6 +267,8 @@ class User < ApplicationRecord
     super && blocked_at.nil?
   end
 
+  def unverified_email? = !email_verified_at?
+
   private
 
   def does_not_merge_on_self

spec/lib/balancer_delivery_method_spec.rb

@@ -1,7 +1,11 @@
 RSpec.describe BalancerDeliveryMethod do
   class ExampleMailer < ApplicationMailer
-    def greet(name)
-      mail(to: "smtp_to", from: "smtp_from", body: "Hello #{name}")
+    def greet(name, bypass_unverified_mail_protection: true)
+      mail(to: name, from: "smtp_from", body: "Hello #{name}")
+
+      if bypass_unverified_mail_protection
+        headers['BYPASS_UNVERIFIED_MAIL_PROTECTION'] = true
+      end
     end
   end
 
@@ -9,7 +13,8 @@ RSpec.describe BalancerDeliveryMethod do
     before_action :set_x_deliver_with
 
     def greet(name)
-      mail(to: "smtp_to", from: "smtp_from", body: "Hello #{name}")
+      mail(to: name, from: "smtp_from", body: "Hello #{name}")
+      headers['BYPASS_UNVERIFIED_MAIL_PROTECTION'] = true
     end
 
     private
@@ -145,6 +150,57 @@ RSpec.describe BalancerDeliveryMethod do
     end
   end
 
+  context 'when the email does not bypass unverified mail protection' do
+    let(:mail) { ExampleMailer.greet(email, bypass_unverified_mail_protection:) }
+    let(:bypass_unverified_mail_protection) { false }
+
+    before do
+      ActionMailer::Base.balancer_settings = { mock_smtp: 10 }
+      mail.deliver_now
+    end
+
+    context 'when the email belongs to a user' do
+      let(:email) { user.email }
+      let(:user) { create(:user, email: 'u@a.com', email_verified_at:) }
+
+      context 'and the email is not verified' do
+        let(:email_verified_at) { nil }
+
+        it { expect(mail).not_to have_been_delivered_using(MockSmtp) }
+      end
+
+      context 'and the email is not verified but a bypass flag is added' do
+        let(:email_verified_at) { nil }
+        let(:bypass_unverified_mail_protection) { true }
+
+        it { expect(mail).to have_been_delivered_using(MockSmtp) }
+      end
+
+      context 'and the email is verified' do
+        let(:email_verified_at) { Time.current }
+
+        it { expect(mail).to have_been_delivered_using(MockSmtp) }
+      end
+    end
+
+    context 'when the email belongs to a individual' do
+      let(:email) { individual.email }
+      let(:individual) { create(:individual, email: 'u@a.com', email_verified_at:) }
+
+      context 'and the email is not verified' do
+        let(:email_verified_at) { nil }
+
+        it { expect(mail).not_to have_been_delivered_using(MockSmtp) }
+      end
+
+      context 'and the email is verified' do
+        let(:email_verified_at) { Time.current }
+
+        it { expect(mail).to have_been_delivered_using(MockSmtp) }
+      end
+    end
+  end
+
   # Helpers
 
   def have_been_delivered_using(delivery_class)