1 files changed, 55 insertions, 0 deletions
diff --git a/spec/lib/gitlab/background_migration/backfill_namespace_details_spec.rb b/spec/lib/gitlab/background_migration/backfill_namespace_details_spec.rb
new file mode 100644
index 00000000000..b6282de0da6
--- /dev/null
+++ b/spec/lib/gitlab/background_migration/backfill_namespace_details_spec.rb
@@ -0,0 +1,55 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Gitlab::BackgroundMigration::BackfillNamespaceDetails, :migration do
+  let(:namespaces) { table(:namespaces) }
+  let(:namespace_details) { table(:namespace_details) }
+
+  subject(:perform_migration) do
+    described_class.new(start_id: namespaces.minimum(:id),
+                        end_id: namespaces.maximum(:id),
+                        batch_table: :namespaces,
+                        batch_column: :id,
+                        sub_batch_size: 2,
+                        pause_ms: 0,
+                        connection: ActiveRecord::Base.connection)
+                   .perform
+  end
+
+  describe '#perform' do
+    it 'creates details for all namespaces in range' do
+      namespace1 = namespaces.create!(id: 5, name: 'test1', path: 'test1', description: "Some description1",
+                                      description_html: "Some description html1", cached_markdown_version: 4)
+      namespaces.create!(id: 6, name: 'test2', path: 'test2', type: 'Project',
+                         description: "Some description2", description_html: "Some description html2",
+                         cached_markdown_version: 4)
+      namespace3 = namespaces.create!(id: 7, name: 'test3', path: 'test3', description: "Some description3",
+                                      description_html: "Some description html3", cached_markdown_version: 4)
+      namespace4 = namespaces.create!(id: 8, name: 'test4', path: 'test4', description: "Some description3",
+                                      description_html: "Some description html4", cached_markdown_version: 4)
+      namespace_details.delete_all
+
+      expect(namespace_details.pluck(:namespace_id)).to eql []
+
+      expect { perform_migration }
+        .to change { namespace_details.pluck(:namespace_id) }.from([]).to contain_exactly(
+          namespace1.id,
+          namespace3.id,
+          namespace4.id
+        )
+
+      expect(namespace_details.find_by_namespace_id(namespace1.id)).to have_attributes(migrated_attributes(namespace1))
+      expect(namespace_details.find_by_namespace_id(namespace3.id)).to have_attributes(migrated_attributes(namespace3))
+      expect(namespace_details.find_by_namespace_id(namespace4.id)).to have_attributes(migrated_attributes(namespace4))
+    end
+  end
+
+  def migrated_attributes(namespace)
+    {
+      description: namespace.description,
+      description_html: namespace.description_html,
+      cached_markdown_version: namespace.cached_markdown_version
+    }
+  end
+end