Change discussion_ids on promoted epics notes

Notes on epics promoted from an issue used to get same discussion_id
as the notes from the issue the epic was promoted from, which would
cause problems when trying to reply to the epic discussion.

2 files changed, 130 insertions, 0 deletions

diff --git a/spec/lib/gitlab/background_migration/fix_promoted_epics_discussion_ids_spec.rb b/spec/lib/gitlab/background_migration/fix_promoted_epics_discussion_ids_spec.rb
new file mode 100644
index 00000000000..73c855ac184
--- /dev/null
+++ b/spec/lib/gitlab/background_migration/fix_promoted_epics_discussion_ids_spec.rb
@@ -0,0 +1,49 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Gitlab::BackgroundMigration::FixPromotedEpicsDiscussionIds, :migration, schema: 20190715193142 do
+  let(:namespaces) { table(:namespaces) }
+  let(:users) { table(:users) }
+  let(:epics) { table(:epics) }
+  let(:notes) { table(:notes) }
+
+  let(:user) { users.create!(email: 'test@example.com', projects_limit: 100, username: 'test') }
+  let(:namespace) { namespaces.create!(name: 'gitlab', path: 'gitlab-org') }
+  let(:epic1) { epics.create!(id: 1, author_id: user.id, iid: 1, group_id: namespace.id, title: 'Epic with discussion', title_html: 'Epic with discussion') }
+
+  def create_note(discussion_id)
+    notes.create!(note: 'note comment',
+                  noteable_id: epic1.id,
+                  noteable_type: 'Epic',
+                  discussion_id: discussion_id)
+  end
+
+  def expect_valid_discussion_id(id)
+    expect(id).to match(/\A\h{40}\z/)
+  end
+
+  describe '#perform with batch of discussion ids' do
+    it 'updates discussion ids' do
+      note1 = create_note('00000000')
+      note2 = create_note('00000000')
+      note3 = create_note('10000000')
+
+      subject.perform(%w(00000000 10000000))
+
+      expect_valid_discussion_id(note1.reload.discussion_id)
+      expect_valid_discussion_id(note2.reload.discussion_id)
+      expect_valid_discussion_id(note3.reload.discussion_id)
+      expect(note1.discussion_id).to eq(note2.discussion_id)
+      expect(note1.discussion_id).not_to eq(note3.discussion_id)
+    end
+
+    it 'skips notes with discussion id not in range' do
+      note4 = create_note('20000000')
+
+      subject.perform(%w(00000000 10000000))
+
+      expect(note4.reload.discussion_id).to eq('20000000')
+    end
+  end
+end
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..5e25d1aed82
--- /dev/null
+++ b/spec/migrations/migrate_discussion_id_on_promoted_epics_spec.rb
@@ -0,0 +1,81 @@
+# 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 = create_note(model, id, { system: true,
+                                    note: 'promoted from issue XXX' })
+    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, extra_params = {})
+    params = {
+      note: 'note',
+      noteable_id: model.id,
+      noteable_type: model.class.name,
+      discussion_id: id
+    }.merge(extra_params)
+
+    notes.create!(params)
+  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