Remove User#internal_attributes method

It's not needed anymore as we've replaced boolean `support_bot` with
enum `bot_type`.

app/models/user.rb

@@ -537,20 +537,16 @@ class User < ApplicationRecord
     username
   end
 
-  def self.internal_attributes
-    [:ghost]
-  end
-
   def internal?
-    self.class.internal_attributes.any? { |a| self[a] }
+    ghost?
   end
 
   def self.internal
-    where(Hash[internal_attributes.zip([true] * internal_attributes.size)])
+    where(ghost: true)
   end
 
   def self.non_internal
-    where(internal_attributes.map { |attr| "#{attr} IS NOT TRUE" }.join(" AND "))
+    where('ghost IS NOT TRUE')
   end
 
   #

ee/app/models/ee/user.rb

@@ -70,21 +70,32 @@ module EE
       # Note: When adding an option, it's value MUST equal to the last value + 1.
       enum group_view: { details: 1, security_dashboard: 2 }, _prefix: true
       scope :group_view_details, -> { where('group_view = ? OR group_view IS NULL', group_view[:details]) }
+
+      enum bot_type: {
+        support_bot: 1
+      }
     end
 
     class_methods do
+      extend ::Gitlab::Utils::Override
+
       def support_bot
         email_pattern = "support%s@#{Settings.gitlab.host}"
 
-        unique_internal(where(support_bot: true), 'support-bot', email_pattern) do |u|
+        unique_internal(where(bot_type: :support_bot), 'support-bot', email_pattern) do |u|
           u.bio = 'The GitLab support bot used for Service Desk'
           u.name = 'GitLab Support Bot'
         end
       end
 
-      # override
-      def internal_attributes
-        super + [:support_bot]
+      override :internal
+      def internal
+        super.or(where.not(bot_type: nil))
+      end
+
+      override :non_internal
+      def non_internal
+        super.where(bot_type: nil)
       end
 
       def non_ldap
@@ -224,6 +235,14 @@ module EE
       super
     end
 
+    def internal?
+      super || bot?
+    end
+
+    def bot?
+      bot_type.present?
+    end
+
     protected
 
     override :password_required?

ee/spec/models/user_spec.rb

@@ -519,4 +519,31 @@ describe User do
       end
     end
   end
+
+  describe 'internal methods' do
+    let!(:user) { create(:user) }
+    let!(:ghost) { User.ghost }
+    let!(:support_bot) { User.support_bot }
+    let!(:non_internal) { [user] }
+    let!(:internal) { [ghost, support_bot] }
+
+    it 'returns non internal users' do
+      expect(User.internal).to eq(internal)
+      expect(internal.all?(&:internal?)).to eq(true)
+    end
+
+    it 'returns internal users' do
+      expect(User.non_internal).to eq(non_internal)
+      expect(non_internal.all?(&:internal?)).to eq(false)
+    end
+
+    describe '#bot?' do
+      it 'marks bot users' do
+        expect(user.bot?).to eq(false)
+        expect(ghost.bot?).to eq(false)
+
+        expect(support_bot.bot?).to eq(true)
+      end
+    end
+  end
 end