Fix orphaned promoted issues

Fix promoted issues with missing promoted_to_epic_id field.

db/post_migrate/20200207184023_add_temporary_index_to_promotion_notes.rb

+# frozen_string_literal: true
+
+# See http://doc.gitlab.com/ce/development/migration_style_guide.html
+# for more information on how to write migrations for GitLab.
+
+class AddTemporaryIndexToPromotionNotes < ActiveRecord::Migration[6.0]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  def up
+    add_concurrent_index :notes,
+      :note,
+      where: "noteable_type = 'Issue' AND system IS TRUE AND note LIKE 'promoted to epic%'",
+      name: 'tmp_idx_on_promoted_notes'
+  end
+
+  def down
+    # NO OP
+  end
+end

db/post_migrate/20200207185149_schedule_fix_orphan_promoted_issues.rb

+# frozen_string_literal: true
+
+class ScheduleFixOrphanPromotedIssues < ActiveRecord::Migration[5.2]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+  BATCH_SIZE = 100
+  BACKGROUND_MIGRATION = 'FixOrphanPromotedIssues'.freeze
+
+  disable_ddl_transaction!
+
+  class Note < ActiveRecord::Base
+    include EachBatch
+
+    self.table_name = 'notes'
+
+    scope :of_promotion, -> do
+      where(noteable_type: 'Issue')
+        .where('notes.system IS TRUE')
+        .where("notes.note LIKE 'promoted to epic%'")
+    end
+  end
+
+  def up
+    Note.of_promotion.each_batch(of: BATCH_SIZE) do |notes, index|
+      jobs = notes.map { |note| [BACKGROUND_MIGRATION, [note.id]] }
+
+      BackgroundMigrationWorker.bulk_perform_async(jobs)
+    end
+  end
+
+  def down
+    # NO OP
+  end
+end

db/schema.rb

@@ -2811,6 +2811,7 @@ ActiveRecord::Schema.define(version: 2020_02_13_220211) do
     t.index ["id"], name: "epic_mentions_temp_index", where: "((note ~~ '%@%'::text) AND ((noteable_type)::text = 'Epic'::text))"
     t.index ["line_code"], name: "index_notes_on_line_code"
     t.index ["note"], name: "index_notes_on_note_trigram", opclass: :gin_trgm_ops, using: :gin
+    t.index ["note"], name: "tmp_idx_on_promoted_notes", where: "(((noteable_type)::text = 'Issue'::text) AND (system IS TRUE) AND (note ~~ 'promoted to epic%'::text))"
     t.index ["noteable_id", "noteable_type"], name: "index_notes_on_noteable_id_and_noteable_type"
     t.index ["project_id", "id"], name: "index_notes_on_project_id_and_id_and_system_false", where: "(NOT system)"
     t.index ["project_id", "noteable_type"], name: "index_notes_on_project_id_and_noteable_type"

ee/changelogs/unreleased/issue_194177.yml

+---
+title: Fix orphan issues that were promoted to epics
+merge_request: 23916
+author:
+type: fixed

ee/lib/ee/gitlab/background_migration/fix_orphan_promoted_issues.rb

+# frozen_string_literal: true
+module EE
+  module Gitlab
+    module BackgroundMigration
+      # This migration populates issues that were promoted to epics
+      # and have null promoted_to_epic_id.
+      # For more information please check https://gitlab.com/gitlab-org/gitlab/issues/194177
+      module FixOrphanPromotedIssues
+        extend ::Gitlab::Utils::Override
+
+        override :perform
+        def perform(note_id)
+          ActiveRecord::Base.connection.execute <<~SQL
+            WITH promotion_notes AS (
+              SELECT noteable_id, note as promotion_note, projects.namespace_id as epic_group_id FROM notes
+              INNER JOIN projects ON notes.project_id = projects.id
+              WHERE notes.noteable_type = 'Issue'
+              AND notes.system IS TRUE
+              AND notes.note like 'promoted to epic%'
+              AND notes.id = #{Integer(note_id)}
+            ), promoted_epics AS (
+              SELECT epics.id as promoted_epic_id, promotion_notes.noteable_id as issue_id FROM epics
+              INNER JOIN promotion_notes on epics.group_id = promotion_notes.epic_group_id
+              WHERE concat('promoted to epic &', epics.iid) = promotion_notes.promotion_note
+            )
+            UPDATE issues
+            SET promoted_to_epic_id = promoted_epic_id
+            FROM promoted_epics
+            WHERE issues.id = promoted_epics.issue_id
+            AND issues.promoted_to_epic_id IS NULL
+          SQL
+        rescue ArgumentError
+        end
+      end
+    end
+  end
+end

ee/spec/lib/gitlab/background_migration/fix_orphan_promoted_issues_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Gitlab::BackgroundMigration::FixOrphanPromotedIssues, :migration, schema: 20200207185149 do
+  let(:users) { table(:users) }
+  let(:namespaces) { table(:namespaces) }
+  let(:projects) { table(:projects) }
+  let(:issues) { table(:issues) }
+  let(:epics) { table(:epics) }
+  let(:notes) { table(:notes) }
+  let(:migration) { described_class.new }
+  let(:group1) { namespaces.create!(name: 'gitlab', path: 'gitlab') }
+  let(:project1) { projects.create!(namespace_id: group1.id) }
+  let(:group2) { namespaces.create!(name: 'other', path: 'other') }
+  let(:project2) { projects.create!(namespace_id: group2.id) }
+  let(:user) { users.create(name: 'any', email: 'user@example.com', projects_limit: 9) }
+  let!(:epic_from_issue_1) { epics.create(iid: 14532, title: 'from issue 1', group_id: group1.id, author_id: user.id, created_at: Time.now, updated_at: Time.now, title_html: 'any') }
+  let!(:epic_from_issue_2) { epics.create(iid: 209, title: 'from issue 2', group_id: group2.id, author_id: user.id, created_at: Time.now, updated_at: Time.now, title_html: 'any') }
+  let!(:promoted_orphan) { issues.create!(description: 'promoted 1', state_id: 1, project_id: project1.id) }
+  let!(:promoted) { issues.create!(description: 'promoted 3', state_id: 2, project_id: project2.id, promoted_to_epic_id: epic_from_issue_2.id) }
+  let!(:promotion_note_1) { notes.create!(project_id: project1.id, noteable_id: promoted_orphan.id, noteable_type: "Issue", note: "promoted to epic &14532", system: true) }
+  let!(:promotion_note_2) { notes.create!(project_id: project2.id, noteable_id: promoted.id, noteable_type: "Issue", note: "promoted to epic &209", system: true) }
+
+  context 'when promoted_to_epic_id is missing' do
+    it 'populates missing promoted_to_epic_id' do
+      expect do
+        described_class.new.perform(promotion_note_1.id)
+        promoted_orphan.reload
+      end.to change { promoted_orphan.promoted_to_epic_id }.from(nil).to(epic_from_issue_1.id)
+    end
+  end
+
+  context 'when promoted_to_epic_id is present' do
+    it 'does not change promoted_to_epic_id' do
+      expect do
+        described_class.new.perform(promotion_note_2.id)
+        promoted.reload
+      end.not_to change { promoted.promoted_to_epic_id }
+    end
+  end
+end

ee/spec/migrations/schedule_fix_orphan_promoted_issues_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+require Rails.root.join('db', 'post_migrate', '20200207185149_schedule_fix_orphan_promoted_issues.rb')
+
+describe ScheduleFixOrphanPromotedIssues, :migration do
+  let(:projects) { table(:projects) }
+  let(:notes) { table(:notes) }
+  let(:project1) { projects.create!(namespace_id: 99) }
+  let!(:promote_orphan_1_note) { notes.create!(project_id: project1.id, noteable_id: 1, noteable_type: "Issue", note: "promoted to epic &14532", system: true) }
+  let!(:promote_orphan_2_note) { notes.create!(project_id: project1.id, noteable_id: 2, noteable_type: "Issue", note: "promoted to epic &209", system: true) }
+  let!(:promote_orphan_3_note) { notes.create!(project_id: project1.id, noteable_id: 4, noteable_type: "Issue", note: "promoted to epic &12", system: true) }
+
+  it 'correctly schedules background migrations' do
+    stub_const("#{described_class.name}::BATCH_SIZE", 2)
+
+    Sidekiq::Testing.fake! do
+      Timecop.freeze do
+        migrate!
+
+        expect(described_class::BACKGROUND_MIGRATION).to be_scheduled_migration(promote_orphan_1_note.id)
+        expect(described_class::BACKGROUND_MIGRATION).to be_scheduled_migration(promote_orphan_2_note.id)
+        expect(described_class::BACKGROUND_MIGRATION).to be_scheduled_migration(promote_orphan_3_note.id)
+        expect(BackgroundMigrationWorker.jobs.size).to eq(3)
+      end
+    end
+  end
+end

lib/gitlab/background_migration/fix_orphan_promoted_issues.rb

+# frozen_string_literal: true
+
+module Gitlab
+  module BackgroundMigration
+    # No OP for CE
+    class FixOrphanPromotedIssues
+      def perform(note_id)
+      end
+    end
+  end
+end
+
+Gitlab::BackgroundMigration::FixOrphanPromotedIssues.prepend_if_ee('EE::Gitlab::BackgroundMigration::FixOrphanPromotedIssues')