Prevent user from changing username with container registry tags

app/models/user.rb

@@ -148,6 +148,8 @@ class User < ActiveRecord::Base
     uniqueness: { case_sensitive: false }
 
   validate :namespace_uniq, if: :username_changed?
+  validate :namespace_move_dir_allowed, if: :username_changed?
+
   validate :avatar_type, if: ->(user) { user.avatar.present? && user.avatar_changed? }
   validate :unique_email, if: :email_changed?
   validate :owns_notification_email, if: :notification_email_changed?
@@ -487,6 +489,12 @@ class User < ActiveRecord::Base
     end
   end
 
+  def namespace_move_dir_allowed
+    if namespace&.any_project_has_container_registry_tags?
+      errors.add(:username, 'cannot be changed if a personal project has container registry tags.')
+    end
+  end
+
   def avatar_type
     unless avatar.image?
       errors.add :avatar, "only images allowed"

changelogs/unreleased/mk-validate-username-change-with-container-registry-tags.yml

+---
+title: Add missing validation error for username change with container registry tags
+merge_request: 13356
+author:

spec/models/user_spec.rb

@@ -118,6 +118,17 @@ describe User do
 
         expect(user).to validate_uniqueness_of(:username).case_insensitive
       end
+
+      context 'when username is changed' do
+        let(:user) { build_stubbed(:user, username: 'old_path', namespace: build_stubbed(:namespace)) }
+
+        it 'validates move_dir is allowed for the namespace' do
+          expect(user.namespace).to receive(:any_project_has_container_registry_tags?).and_return(true)
+          user.username = 'new_path'
+          expect(user).to be_invalid
+          expect(user.errors.messages[:username].first).to match('cannot be changed if a personal project has container registry tags')
+        end
+      end
     end
 
     it { is_expected.to validate_presence_of(:projects_limit) }

spec/serializers/pipeline_serializer_spec.rb

@@ -111,7 +111,7 @@ describe PipelineSerializer do
       shared_examples 'no N+1 queries' do
         it 'verifies number of queries', :request_store do
           recorded = ActiveRecord::QueryRecorder.new { subject }
-          expect(recorded.count).to be_within(1).of(59)
+          expect(recorded.count).to be_within(1).of(57)
           expect(recorded.cached_count).to eq(0)
         end
       end