1 files changed, 42 insertions, 0 deletions
diff --git a/spec/lib/gitlab/background_migration/backfill_packages_tags_project_id_spec.rb b/spec/lib/gitlab/background_migration/backfill_packages_tags_project_id_spec.rb
new file mode 100644
index 00000000000..423d9fe76ac
--- /dev/null
+++ b/spec/lib/gitlab/background_migration/backfill_packages_tags_project_id_spec.rb
@@ -0,0 +1,42 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Gitlab::BackgroundMigration::BackfillPackagesTagsProjectId,
+  feature_category: :package_registry,
+  schema: 20231030051837 do # schema before we introduced the invalid not-null constraint
+  let!(:tags_without_project_id) do
+    (0...13).map do |i|
+      namespace = table(:namespaces).create!(name: 'my namespace', path: 'my-namespace')
+      project = table(:projects).create!(name: 'my project', path: 'my-project', namespace_id: namespace.id,
+        project_namespace_id: namespace.id)
+      package = table(:packages_packages).create!(project_id: project.id, created_at: Time.current,
+        updated_at: Time.current, name: "Package #{i}", package_type: 1, status: 1)
+      table(:packages_tags).create!(package_id: package.id, name: "Tag #{i}", created_at: Time.current,
+        updated_at: Time.current, project_id: nil)
+    end
+  end
+
+  let!(:starting_id) { table(:packages_tags).pluck(:id).min }
+  let!(:end_id) { table(:packages_tags).pluck(:id).max }
+
+  let!(:migration) do
+    described_class.new(
+      start_id: starting_id,
+      end_id: end_id,
+      batch_table: :packages_tags,
+      batch_column: :id,
+      sub_batch_size: 10,
+      pause_ms: 2,
+      connection: ::ApplicationRecord.connection
+    )
+  end
+
+  it 'backfills the missing project_id for the batch' do
+    expect do
+      migration.perform
+    end.to change { table(:packages_tags).where(project_id: nil).count }
+      .from(13)
+      .to(0)
+  end
+end