Drop User.system and replace with Account#system_user

app/models/account.rb

@@ -31,4 +31,8 @@ class Account < ApplicationRecord
   def account
     self
   end
+
+  def system_user
+    users.where(role: :system).first!
+  end
 end

app/models/board/accessible.rb

@@ -49,7 +49,7 @@ module Board::Accessible
   end
 
   def watchers
-    users.without(User.system).where(accesses: { involvement: :watching })
+    users.active.where(accesses: { involvement: :watching })
   end
 
   private

app/models/card/entropic.rb

@@ -26,7 +26,7 @@ module Card::Entropic
   class_methods do
     def auto_postpone_all_due
       due_to_be_postponed.find_each do |card|
-        card.auto_postpone(user: User.system)
+        card.auto_postpone(user: card.account.system_user)
       end
     end
   end

app/models/card/eventable/system_commenter.rb

@@ -8,7 +8,7 @@ class Card::Eventable::SystemCommenter
   def comment
     return unless comment_body.present?
 
-    card.comments.create! creator: User.system, body: comment_body, created_at: event.created_at
+    card.comments.create! creator: card.account.system_user, body: comment_body, created_at: event.created_at
   end
 
   private

app/models/user/role.rb

@@ -8,12 +8,6 @@ module User::Role
     scope :active, -> { where(active: true, role: %i[ admin member ]) }
   end
 
-  class_methods do
-    def system
-      find_or_create_by!(account: Current.account, role: :system) { it.name = "System" }
-    end
-  end
-
   def can_change?(other)
     admin? || other == self
   end

app/views/cards/comments/_watchers.html.erb

@@ -2,11 +2,11 @@
   <strong class="txt-uppercase">Subscribers</strong>
 
   <p class="margin-none-block-start margin-block-end-half">
-    <%= pluralize(card.watchers.without(User.system).count, "person") %> will be notified when someone comments on this.
+    <%= pluralize(card.watchers.active.count, "person") %> will be notified when someone comments on this.
   </p>
 
   <div class="flex align-center flex-wrap gap-half max-width txt-normal">
-    <% card.watchers.without(User.system).alphabetically.each do |watcher| %>
+    <% card.watchers.active.alphabetically.each do |watcher| %>
       <%= avatar_tag watcher %>
     <% end %>
   </div>

test/fixtures/users.yml

@@ -31,3 +31,9 @@ mike:
   role: admin
   identity: mike
   account: initech_uuid
+
+system_initech:
+  id: <%= ActiveRecord::FixtureSet.identify("system_initech", :uuid) %>
+  name: System
+  role: system
+  account: initech_uuid

test/models/account_test.rb

@@ -41,6 +41,22 @@ class AccountTest < ActiveSupport::TestCase
       assert_equal "David", admin.name
       assert_equal "david@37signals.com", admin.identity.email_address
       assert_equal "admin", admin.role
+
+      assert_predicate account.system_user, :present?
+    end
+  end
+
+  test "#system_user returns the system user of the account" do
+    system_user = User.find_by!(account: accounts("37s"), role: :system)
+
+    assert_equal system_user, accounts("37s").system_user
+  end
+
+  test "#system_user raises if there is no system user" do
+    account = Account.create!(name: "No System User Account")
+
+    assert_raises ActiveRecord::RecordNotFound do
+      account.system_user
     end
   end
 end

test/models/card/entropic_test.rb

@@ -43,7 +43,7 @@ class Card::EntropicTest < ActiveSupport::TestCase
     end
 
     assert cards(:logo).reload.postponed?
-    assert_equal User.system, cards(:logo).postponed_by
+    assert_equal accounts("37s").system_user, cards(:logo).postponed_by
     assert_not cards(:shipping).reload.postponed?
   end
 

test/models/notifier/event_notifier_test.rb

@@ -7,7 +7,7 @@ class Notifier::EventNotifierTest < ActiveSupport::TestCase
 
   test "generate does not create notifications if the event was system-generated" do
     cards(:logo).drafted!
-    events(:logo_published).update!(creator: User.system)
+    events(:logo_published).update!(creator: accounts("37s").system_user)
 
     assert_no_difference -> { Notification.count } do
       Notifier.for(events(:logo_published)).notify

test/models/user_test.rb

@@ -35,14 +35,4 @@ class UserTest < ActiveSupport::TestCase
     assert_equal "DHH", User.new(name: "David Heinemeier Hansson").initials
     assert_equal "ÉLH", User.new(name: "Éva-Louise Hernández").initials
   end
-
-  test "system user" do
-    system_user = User.system
-
-    assert system_user.system?
-    assert_equal "System", system_user.name
-    assert_equal "S", system_user.initials
-
-    assert_not_includes User.active, system_user
-  end
 end