Remove MergeRequestAssigneesMigrationProgressCheck background migration

Removes an old background mutation

db/post_migrate/20190402224749_schedule_merge_request_assignees_migration_progress_check.rb

-# frozen_string_literal: true
-
-class ScheduleMergeRequestAssigneesMigrationProgressCheck < ActiveRecord::Migration[5.0]
-  include Gitlab::Database::MigrationHelpers
-
-  MIGRATION = 'MergeRequestAssigneesMigrationProgressCheck'
-
-  DOWNTIME = false
-
-  disable_ddl_transaction!
-
-  def up
-    BackgroundMigrationWorker.perform_async(MIGRATION)
-  end
-
-  def down
-  end
-end

db/schema_migrations/20190402224749

-f655a3f9f1f41710ae501c3e4ef0893791c28971d87e12f87d4b65131502b812
\ No newline at end of file

lib/gitlab/background_migration/merge_request_assignees_migration_progress_check.rb

-# frozen_string_literal: true
-
-module Gitlab
-  module BackgroundMigration
-    # rubocop: disable Style/Documentation
-    class MergeRequestAssigneesMigrationProgressCheck
-      include Gitlab::Utils::StrongMemoize
-
-      RESCHEDULE_DELAY = 3.hours
-      WORKER = 'PopulateMergeRequestAssigneesTable'
-      DeadJobsError = Class.new(StandardError)
-
-      def perform
-        raise DeadJobsError, "Only dead background jobs in the queue for #{WORKER}" if !ongoing? && dead_jobs?
-
-        if ongoing?
-          BackgroundMigrationWorker.perform_in(RESCHEDULE_DELAY, self.class.name)
-        else
-          Feature.enable(:multiple_merge_request_assignees)
-        end
-      end
-
-      private
-
-      def dead_jobs?
-        strong_memoize(:dead_jobs) do
-          migration_klass.dead_jobs?(WORKER)
-        end
-      end
-
-      def ongoing?
-        strong_memoize(:ongoing) do
-          migration_klass.exists?(WORKER) || migration_klass.retrying_jobs?(WORKER)
-        end
-      end
-
-      def migration_klass
-        Gitlab::BackgroundMigration
-      end
-    end
-    # rubocop: enable Style/Documentation
-  end
-end

spec/lib/gitlab/background_migration/merge_request_assignees_migration_progress_check_spec.rb

-# frozen_string_literal: true
-
-require 'spec_helper'
-
-RSpec.describe Gitlab::BackgroundMigration::MergeRequestAssigneesMigrationProgressCheck do
-  context 'rescheduling' do
-    context 'when there are ongoing and no dead jobs' do
-      it 'reschedules check' do
-        allow(Gitlab::BackgroundMigration).to receive(:exists?)
-                                                .with('PopulateMergeRequestAssigneesTable')
-                                                .and_return(true)
-
-        allow(Gitlab::BackgroundMigration).to receive(:dead_jobs?)
-                                                .with('PopulateMergeRequestAssigneesTable')
-                                                .and_return(false)
-
-        expect(BackgroundMigrationWorker).to receive(:perform_in).with(described_class::RESCHEDULE_DELAY, described_class.name)
-
-        described_class.new.perform
-      end
-    end
-
-    context 'when there are ongoing and dead jobs' do
-      it 'reschedules check' do
-        allow(Gitlab::BackgroundMigration).to receive(:exists?)
-                                                .with('PopulateMergeRequestAssigneesTable')
-                                                .and_return(true)
-
-        allow(Gitlab::BackgroundMigration).to receive(:dead_jobs?)
-                                                .with('PopulateMergeRequestAssigneesTable')
-                                                .and_return(true)
-
-        expect(BackgroundMigrationWorker).to receive(:perform_in).with(described_class::RESCHEDULE_DELAY, described_class.name)
-
-        described_class.new.perform
-      end
-    end
-
-    context 'when there retrying jobs and no scheduled' do
-      it 'reschedules check' do
-        allow(Gitlab::BackgroundMigration).to receive(:exists?)
-                                                .with('PopulateMergeRequestAssigneesTable')
-                                                .and_return(false)
-
-        allow(Gitlab::BackgroundMigration).to receive(:retrying_jobs?)
-                                                .with('PopulateMergeRequestAssigneesTable')
-                                                .and_return(true)
-
-        expect(BackgroundMigrationWorker).to receive(:perform_in).with(described_class::RESCHEDULE_DELAY, described_class.name)
-
-        described_class.new.perform
-      end
-    end
-  end
-
-  context 'when there are no scheduled, or retrying or dead' do
-    before do
-      stub_feature_flags(multiple_merge_request_assignees: false)
-    end
-
-    it 'enables feature' do
-      allow(Gitlab::BackgroundMigration).to receive(:exists?)
-                                              .with('PopulateMergeRequestAssigneesTable')
-                                              .and_return(false)
-
-      allow(Gitlab::BackgroundMigration).to receive(:retrying_jobs?)
-                                              .with('PopulateMergeRequestAssigneesTable')
-                                              .and_return(false)
-
-      allow(Gitlab::BackgroundMigration).to receive(:dead_jobs?)
-                                              .with('PopulateMergeRequestAssigneesTable')
-                                              .and_return(false)
-
-      described_class.new.perform
-
-      expect(Feature.enabled?(:multiple_merge_request_assignees, type: :licensed)).to eq(true)
-    end
-  end
-
-  context 'when there are only dead jobs' do
-    it 'raises DeadJobsError error' do
-      allow(Gitlab::BackgroundMigration).to receive(:exists?)
-                                              .with('PopulateMergeRequestAssigneesTable')
-                                              .and_return(false)
-
-      allow(Gitlab::BackgroundMigration).to receive(:retrying_jobs?)
-                                              .with('PopulateMergeRequestAssigneesTable')
-                                              .and_return(false)
-
-      allow(Gitlab::BackgroundMigration).to receive(:dead_jobs?)
-                                              .with('PopulateMergeRequestAssigneesTable')
-                                              .and_return(true)
-
-      expect { described_class.new.perform }
-        .to raise_error(described_class::DeadJobsError,
-                        "Only dead background jobs in the queue for #{described_class::WORKER}")
-    end
-  end
-end

spec/migrations/schedule_merge_request_assignees_migration_progress_check_spec.rb

-# frozen_string_literal: true
-
-require 'spec_helper'
-require Rails.root.join('db', 'post_migrate', '20190402224749_schedule_merge_request_assignees_migration_progress_check.rb')
-
-RSpec.describe ScheduleMergeRequestAssigneesMigrationProgressCheck do
-  describe '#up' do
-    it 'schedules MergeRequestAssigneesMigrationProgressCheck background job' do
-      expect(BackgroundMigrationWorker).to receive(:perform_async)
-                                             .with(described_class::MIGRATION)
-                                             .and_call_original
-
-      subject.up
-    end
-  end
-end