1 files changed, 57 insertions, 0 deletions
diff --git a/spec/lib/gitlab/background_migration/backfill_project_namespace_on_issues_spec.rb b/spec/lib/gitlab/background_migration/backfill_project_namespace_on_issues_spec.rb
new file mode 100644
index 00000000000..29833074109
--- /dev/null
+++ b/spec/lib/gitlab/background_migration/backfill_project_namespace_on_issues_spec.rb
@@ -0,0 +1,57 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+# todo: this will need to specify schema version once we introduce the not null constraint on issues#namespace_id
+# https://gitlab.com/gitlab-org/gitlab/-/issues/367835
+RSpec.describe Gitlab::BackgroundMigration::BackfillProjectNamespaceOnIssues do
+  let(:namespaces) { table(:namespaces) }
+  let(:projects) { table(:projects) }
+  let(:issues) { table(:issues) }
+
+  let(:namespace1) { namespaces.create!(name: 'batchtest1', type: 'Group', path: 'space1') }
+  let(:namespace2) { namespaces.create!(name: 'batchtest2', type: 'Group', parent_id: namespace1.id, path: 'space2') }
+
+  let(:proj_namespace1) { namespaces.create!(name: 'proj1', path: 'proj1', type: 'Project', parent_id: namespace1.id) }
+  let(:proj_namespace2) { namespaces.create!(name: 'proj2', path: 'proj2', type: 'Project', parent_id: namespace2.id) }
+
+  # rubocop:disable Layout/LineLength
+  let(:proj1) { projects.create!(name: 'proj1', path: 'proj1', namespace_id: namespace1.id, project_namespace_id: proj_namespace1.id) }
+  let(:proj2) { projects.create!(name: 'proj2', path: 'proj2', namespace_id: namespace2.id, project_namespace_id: proj_namespace2.id) }
+
+  let!(:proj1_issue_with_namespace) { issues.create!(title: 'issue1', project_id: proj1.id, namespace_id: proj_namespace1.id) }
+  let!(:proj1_issue_without_namespace1) { issues.create!(title: 'issue2', project_id: proj1.id) }
+  let!(:proj1_issue_without_namespace2) { issues.create!(title: 'issue3', project_id: proj1.id) }
+  let!(:proj2_issue_with_namespace) { issues.create!(title: 'issue4', project_id: proj2.id, namespace_id: proj_namespace2.id) }
+  let!(:proj2_issue_without_namespace1) { issues.create!(title: 'issue5', project_id: proj2.id) }
+  let!(:proj2_issue_without_namespace2) { issues.create!(title: 'issue6', project_id: proj2.id) }
+  # rubocop:enable Layout/LineLength
+
+  let(:migration) do
+    described_class.new(
+      start_id: proj1_issue_with_namespace.id,
+      end_id: proj2_issue_without_namespace2.id,
+      batch_table: :issues,
+      batch_column: :id,
+      sub_batch_size: 2,
+      pause_ms: 2,
+      connection: ApplicationRecord.connection
+    )
+  end
+
+  subject(:perform_migration) { migration.perform }
+
+  it 'backfills namespace_id for the selected records', :aggregate_failures do
+    perform_migration
+
+    expected_namespaces = [proj_namespace1.id, proj_namespace2.id]
+
+    expect(issues.where.not(namespace_id: nil).count).to eq(6)
+    expect(issues.where.not(namespace_id: nil).pluck(:namespace_id).uniq).to match_array(expected_namespaces)
+  end
+
+  it 'tracks timings of queries' do
+    expect(migration.batch_metrics.timings).to be_empty
+
+    expect { perform_migration }.to change { migration.batch_metrics.timings }
+  end
+end