1 files changed, 77 insertions, 0 deletions
diff --git a/spec/migrations/migrate_discussion_id_on_promoted_epics_spec.rb b/spec/migrations/migrate_discussion_id_on_promoted_epics_spec.rb
new file mode 100644
index 00000000000..57c4bd16f2e
--- /dev/null
+++ b/spec/migrations/migrate_discussion_id_on_promoted_epics_spec.rb
@@ -0,0 +1,77 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+require Rails.root.join('db', 'post_migrate', '20190715193142_migrate_discussion_id_on_promoted_epics.rb')
+
+describe MigrateDiscussionIdOnPromotedEpics, :migration, :sidekiq do
+  let(:migration_class) { described_class::MIGRATION }
+  let(:migration_name)  { migration_class.to_s.demodulize }
+
+  let(:namespaces) { table(:namespaces) }
+  let(:projects) { table(:projects) }
+  let(:users) { table(:users) }
+  let(:issues) { table(:issues) }
+  let(:epics) { table(:epics) }
+  let(:notes) { table(:notes) }
+  let(:system_note_metadata) { table(:system_note_metadata) }
+
+  let(:user) { users.create!(email: 'test@example.com', projects_limit: 100, username: 'test') }
+  let(:namespace) { namespaces.create(name: 'gitlab', path: 'gitlab-org') }
+
+  def create_promotion_note(model, id)
+    note = notes.create!(system: true, note: 'promoted from issue XXX',
+                         noteable_id: model.id,
+                         noteable_type: model.class.name,
+                         discussion_id: id)
+    system_note_metadata.create!(note_id: note.id, action: 'moved')
+  end
+
+  def create_epic
+    epics.create!(author_id: user.id, iid: 1,
+                  group_id: namespace.id,
+                  title: 'Epic with discussion',
+                  title_html: 'Epic with discussion')
+  end
+
+  def create_note(model, id)
+    notes.create!(note: 'note', noteable_id: model.id,
+                  noteable_type: model.class.name, discussion_id: id)
+  end
+
+  context 'with promoted epic' do
+    let(:epic1) { create_epic }
+    let!(:note1) { create_promotion_note(epic1, 'id1') }
+
+    it 'correctly schedules background migrations in batches' do
+      create_note(epic1, 'id2')
+      create_note(epic1, 'id3')
+
+      stub_const("#{described_class.name}::BATCH_SIZE", 2)
+
+      Sidekiq::Testing.fake! do
+        Timecop.freeze do
+          migrate!
+
+          expect(migration_name).to be_scheduled_delayed_migration(2.minutes, %w(id1 id2))
+          expect(migration_name).to be_scheduled_delayed_migration(4.minutes, %w(id3))
+          expect(BackgroundMigrationWorker.jobs.size).to eq(2)
+        end
+      end
+    end
+
+    it 'schedules only promoted epics' do
+      issue = issues.create(description: 'first', state: 'opened')
+      create_promotion_note(issue, 'id2')
+      create_note(create_epic, 'id3')
+
+      Sidekiq::Testing.fake! do
+        Timecop.freeze do
+          migrate!
+
+          expect(migration_name).to be_scheduled_delayed_migration(2.minutes, %w(id1))
+          expect(BackgroundMigrationWorker.jobs.size).to eq(1)
+        end
+      end
+    end
+  end
+end