emails: fix sending emails to invalid addresses.

Fix mailers to not attempt deliveries to invalid or nonexistent email
addresses. This usually happened when someone changed their email, and
we tried to send a confirmation email to a nonexistent address.

app/controllers/password_resets_controller.rb

@@ -9,7 +9,7 @@ class PasswordResetsController < ApplicationController
     if @user.blank?
       flash[:notice] = "That account does not exist"
       redirect_to password_reset_path
-    elsif @user.can_receive_email?(require_verification: false)
+    elsif @user.can_receive_email?(require_verified_email: false)
       UserMailer.password_reset(@user).deliver_later
       UserEvent.create_from_request!(@user, :password_reset, request)
       flash[:notice] = "Password reset email sent. Check your email"

app/controllers/users_controller.rb

@@ -90,7 +90,7 @@ class UsersController < ApplicationController
       flash[:notice] = "Sign up failed: #{@user.errors.full_messages.join("; ")}"
     else
       session[:user_id] = @user.id
-      UserMailer.welcome_user(@user).deliver_later if @user.can_receive_email?(require_verification: false)
+      UserMailer.welcome_user(@user).deliver_later
       set_current_user
     end
 

app/mailers/application_mailer.rb

@@ -5,4 +5,11 @@
 # @see https://guides.rubyonrails.org/action_mailer_basics.html
 class ApplicationMailer < ActionMailer::Base
   default from: "#{Danbooru.config.canonical_app_name} <#{Danbooru.config.contact_email}>", content_type: "text/html"
+
+  def mail(user, require_verified_email:, **options)
+    to = email_address_with_name(user.email_address&.address, user.name)
+    message = super(to: to, **options)
+    message.perform_deliveries = user.can_receive_email?(require_verified_email: require_verified_email)
+    message
+  end
 end

app/mailers/user_mailer.rb

@@ -7,24 +7,24 @@ class UserMailer < ApplicationMailer
   # The email sent when a user receives a DMail.
   def dmail_notice(dmail)
     @dmail = dmail
-    mail to: dmail.to.email_with_name, subject: "#{Danbooru.config.app_name} - Message received from #{dmail.from.name}"
+    mail(dmail.to, require_verified_email: true, subject: "#{Danbooru.config.app_name} - Message received from #{dmail.from.name}")
   end
 
   # The email sent when a user requests a password reset.
   def password_reset(user)
     @user = user
-    mail to: @user.email_with_name, subject: "#{Danbooru.config.app_name} password reset request"
+    mail(@user, require_verified_email: false, subject: "#{Danbooru.config.app_name} password reset request")
   end
 
   # The email sent when a user changes their email address.
   def email_change_confirmation(user)
     @user = user
-    mail to: @user.email_with_name, subject: "Confirm your email address"
+    mail(@user, require_verified_email: false, subject: "Confirm your email address")
   end
 
   # The email sent when a new user signs up with an email address.
   def welcome_user(user)
     @user = user
-    mail to: @user.email_with_name, subject: "Welcome to #{Danbooru.config.app_name}! Confirm your email address"
+    mail(@user, require_verified_email: false, subject: "Welcome to #{Danbooru.config.app_name}! Confirm your email address")
   end
 end

app/models/dmail.rb

@@ -141,7 +141,7 @@ class Dmail < ApplicationRecord
   end
 
   def send_email
-    if is_recipient? && !is_deleted? && to.receive_email_notifications? && to.can_receive_email?
+    if is_recipient? && !is_deleted? && to.receive_email_notifications?
       UserMailer.dmail_notice(self).deliver_later
     end
   end

app/models/user.rb

@@ -361,11 +361,7 @@ class User < ApplicationRecord
   end
 
   module EmailMethods
-    def email_with_name
-      "#{name} <#{email_address.address}>"
-    end
-
-    def can_receive_email?(require_verification: true)
+    def can_receive_email?(require_verified_email: true)
       email_address.present? && email_address.is_deliverable? && (email_address.is_verified? || !require_verification)
     end
 

test/functional/users_controller_test.rb

@@ -259,7 +259,7 @@ class UsersControllerTest < ActionDispatch::IntegrationTest
         assert_equal(User::Levels::MEMBER, User.last.level)
         assert_equal(User.last, User.last.authenticate_password("xxxxx1"))
         assert_nil(User.last.email_address)
-        assert_no_enqueued_emails
+        assert_enqueued_email_with UserMailer, :welcome_user, args: [User.last], queue: "default"
         assert_equal(true, User.last.user_events.user_creation.exists?)
       end
 

test/unit/user_mailer_test.rb

@@ -12,6 +12,20 @@ class UserMailerTest < ActionMailer::TestCase
         mail = UserMailer.dmail_notice(@dmail)
         assert_emails(1) { mail.deliver_now }
       end
+
+      should "not send an email for a user without an email address" do
+        @user = create(:user)
+        @dmail = create(:dmail, owner: @user, to: @user)
+        mail = UserMailer.dmail_notice(@dmail)
+        assert_emails(0) { mail.deliver_now }
+      end
+
+      should "not send an email for a user with an undeliverable address" do
+        @user = create(:user, email_address: build(:email_address, is_deliverable: false))
+        @dmail = create(:dmail, owner: @user, to: @user)
+        mail = UserMailer.dmail_notice(@dmail)
+        assert_emails(0) { mail.deliver_now }
+      end
     end
 
     context "password_reset method" do