1 files changed, 41 insertions, 0 deletions
diff --git a/spec/lib/gitlab/background_migration/backfill_project_settings_spec.rb b/spec/lib/gitlab/background_migration/backfill_project_settings_spec.rb
new file mode 100644
index 00000000000..525c236b644
--- /dev/null
+++ b/spec/lib/gitlab/background_migration/backfill_project_settings_spec.rb
@@ -0,0 +1,41 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Gitlab::BackgroundMigration::BackfillProjectSettings, :migration, schema: 20220324165436 do
+  let(:migration) { described_class.new }
+  let(:namespaces_table) { table(:namespaces) }
+  let(:projects_table) { table(:projects) }
+  let(:project_settings_table) { table(:project_settings) }
+
+  let(:table_name) { 'projects' }
+  let(:batch_column) { :id }
+  let(:sub_batch_size) { 2 }
+  let(:pause_ms) { 0 }
+
+  subject(:perform_migration) { migration.perform(1, 30, table_name, batch_column, sub_batch_size, pause_ms) }
+
+  before do
+    namespaces_table.create!(id: 1, name: 'namespace', path: 'namespace-path', type: 'Group')
+    projects_table.create!(id: 11, name: 'group-project-1', path: 'group-project-path-1', namespace_id: 1)
+    projects_table.create!(id: 12, name: 'group-project-2', path: 'group-project-path-2', namespace_id: 1)
+    project_settings_table.create!(project_id: 11)
+
+    namespaces_table.create!(id: 2, name: 'namespace', path: 'namespace-path', type: 'User')
+    projects_table.create!(id: 21, name: 'user-project-1', path: 'user--project-path-1', namespace_id: 2)
+    projects_table.create!(id: 22, name: 'user-project-2', path: 'user-project-path-2', namespace_id: 2)
+    project_settings_table.create!(project_id: 21)
+  end
+
+  it 'backfills project settings when it does not exist', :aggregate_failures do
+    expect(project_settings_table.count).to eq 2
+
+    queries = ActiveRecord::QueryRecorder.new do
+      perform_migration
+    end
+
+    expect(queries.count).to eq(5)
+
+    expect(project_settings_table.count).to eq 4
+  end
+end