Ensure that pages metadata exists when updating it

This fix is a bit paranoid: pages_metadata was added in 12.*
and created via background migration.

Now it should exists for every project. (this is true for .com)

But if users just upgrade to 13.* after a long wait,
then background migration may still be in-progress, so we want
to ensure that metadata exist before we update it with
deployment_id

app/models/project.rb

@@ -1823,6 +1823,10 @@ class Project < ApplicationRecord
     ensure_pages_metadatum.update!(deployed: false, artifacts_archive: nil, pages_deployment: nil)
   end
 
+  def update_pages_deployment!(deployment)
+    ensure_pages_metadatum.update!(pages_deployment: deployment)
+  end
+
   def write_repository_config(gl_full_path: full_path)
     # We'd need to keep track of project full path otherwise directory tree
     # created with hashed storage enabled cannot be usefully imported using

app/services/projects/update_pages_service.rb

@@ -138,7 +138,7 @@ module Projects
         deployment = project.pages_deployments.create!(file: file,
                                                        file_count: entries_count,
                                                        file_sha256: sha256)
-        project.pages_metadatum.update!(pages_deployment: deployment)
+        project.update_pages_deployment!(deployment)
       end
 
       DestroyPagesDeploymentsWorker.perform_in(

spec/models/project_spec.rb

@@ -5927,6 +5927,26 @@ RSpec.describe Project, factory_default: :keep do
     end
   end
 
+  describe '#update_pages_deployment!' do
+    let(:project) { create(:project) }
+    let(:deployment) { create(:pages_deployment, project: project) }
+
+    it "creates new metadata record if none exists yet and sets deployment" do
+      project.pages_metadatum.destroy!
+      project.reload
+
+      project.update_pages_deployment!(deployment)
+
+      expect(project.pages_metadatum.pages_deployment).to eq(deployment)
+    end
+
+    it "updates the existing metadara record with deployment" do
+      expect do
+        project.update_pages_deployment!(deployment)
+      end.to change { project.pages_metadatum.reload.pages_deployment }.from(nil).to(deployment)
+    end
+  end
+
   describe '#has_pool_repsitory?' do
     it 'returns false when it does not have a pool repository' do
       subject = create(:project, :repository)

spec/services/projects/update_pages_service_spec.rb

@@ -71,6 +71,17 @@ RSpec.describe Projects::UpdatePagesService do
         expect(project.pages_metadatum.reload.pages_deployment_id).to eq(deployment.id)
       end
 
+      it 'does not fail if pages_metadata is absent' do
+        project.pages_metadatum.destroy!
+        project.reload
+
+        expect do
+          expect(execute).to eq(:success)
+        end.to change { project.pages_deployments.count }.by(1)
+
+        expect(project.pages_metadatum.reload.pages_deployment).to eq(project.pages_deployments.last)
+      end
+
       context 'when there is an old pages deployment' do
         let!(:old_deployment_from_another_project) { create(:pages_deployment) }
         let!(:old_deployment) { create(:pages_deployment, project: project) }