Auto-promote DanbooruBot to Mod. Auto-create DanbooruBot if it doesn't exist.

app/models/dmail.rb

@@ -86,7 +86,7 @@ class Dmail < ApplicationRecord
       end
 
       def create_automated(params)
-        dmail = Dmail.new(from: Danbooru.config.system_user, **params)
+        dmail = Dmail.new(from: User.system, **params)
         dmail.owner = dmail.to
         dmail.save
         dmail
@@ -234,7 +234,7 @@ class Dmail < ApplicationRecord
   end
 
   def is_automated?
-    from == Danbooru.config.system_user
+    from == User.system
   end
 
   def filtered?

app/models/user.rb

@@ -316,7 +316,7 @@ class User < ApplicationRecord
 
     module ClassMethods
       def system
-        Danbooru.config.system_user
+        User.find_by!(name: Danbooru.config.system_user)
       end
 
       def level_hash
@@ -366,7 +366,7 @@ class User < ApplicationRecord
     def promote_to_admin_if_first_user
       return if Rails.env.test?
 
-      if User.count == 0
+      if User.admins.count == 0
         self.level = Levels::ADMIN
         self.can_approve_posts = true
         self.can_upload_free = true

config/danbooru_default_config.rb

@@ -37,8 +37,10 @@ module Danbooru
     end
 
     # System actions, such as sending automated dmails, will be performed with this account.
+    # This account will be created automatically if it doesn't exist. It will
+    # be promoted to Moderator if it isn't already a Moderator.
     def system_user
-      User.find_by_name("DanbooruBot") || User.admins.first
+      "DanbooruBot"
     end
 
     def upload_feedback_topic

config/initializers/system_user.rb

@@ -0,0 +1,10 @@
+require "securerandom"
+
+system = User.find_or_create_by!(name: Danbooru.config.system_user) do |user|
+  user.password = SecureRandom.base64(32)
+end
+
+unless system.is_moderator?
+  system.level = User::Levels::MODERATOR
+  system.save
+end

test/unit/dmail_test.rb

@@ -177,7 +177,7 @@ class DmailTest < ActiveSupport::TestCase
     context "that is automated" do
       setup do
         @bot = FactoryGirl.create(:user)
-        Danbooru.config.stubs(:system_user).returns(@bot)
+        User.stubs(:system).returns(@bot)
       end
 
       should "only create a copy for the recipient" do

test/unit/post_disapproval_test.rb

@@ -85,7 +85,7 @@ class PostDisapprovalTest < ActiveSupport::TestCase
 
         should "dmail the uploaders" do
           bot = FactoryGirl.create(:user)
-          Danbooru.config.stubs(:system_user).returns(bot)
+          User.stubs(:system).returns(bot)
 
           assert_difference(["@uploaders[0].dmails.count", "@uploaders[1].dmails.count"], 1) do
             PostDisapproval.dmail_messages!

test/unit/post_replacement_test.rb

@@ -20,7 +20,7 @@ class PostReplacementTest < ActiveSupport::TestCase
     Delayed::Worker.delay_jobs = true # don't delete the old images right away
 
     @system = FactoryGirl.create(:user, created_at: 2.weeks.ago)
-    Danbooru.config.stubs(:system_user).returns(@system)
+    User.stubs(:system).returns(@system)
 
     @uploader = FactoryGirl.create(:user, created_at: 2.weeks.ago, can_upload_free: true)
     @replacer = FactoryGirl.create(:user, created_at: 2.weeks.ago, can_approve_posts: true)

test/unit/user_test.rb

@@ -28,7 +28,7 @@ class UserTest < ActiveSupport::TestCase
 
       should "send an automated dmail to the user" do
         bot = FactoryGirl.create(:user)
-        Danbooru.config.stubs(:system_user).returns(bot)
+        User.stubs(:system).returns(bot)
 
         assert_difference("Dmail.count", 1) do
           @user.promote_to!(User::Levels::GOLD)