Set MR rule to point to project MR

ee/lib/gitlab/background_migration/migrate_approver_to_approval_rules.rb

@@ -29,6 +29,8 @@ module Gitlab
         has_and_belongs_to_many :groups, class_name: 'Group', join_table: :approval_merge_request_rules_groups
         has_and_belongs_to_many :approvals # This is only populated after merge request is merged
         has_many :approved_approvers, through: :approvals, source: :user
+        has_one :approval_merge_request_rule_source
+        has_one :approval_project_rule, through: :approval_merge_request_rule_source
 
         def project
           merge_request.target_project
@@ -63,6 +65,12 @@ module Gitlab
         end
       end
 
+      class ApprovalMergeRequestRuleSource < ApplicationRecord
+        self.table_name = 'approval_merge_request_rule_sources'
+        belongs_to :approval_merge_request_rule
+        belongs_to :approval_project_rule
+      end
+
       class ApprovalProjectRule < ActiveRecord::Base
         self.table_name = 'approval_project_rules'
 
@@ -158,7 +166,10 @@ module Gitlab
 
       def handle_merge_request
         ActiveRecord::Base.transaction do
-          sync_rule
+          if rule = sync_rule
+            rule.approval_project_rule = target.target_project.approval_rules.regular.first
+          end
+
           target.finalize_approvals if target.merged?
         end
       end
@@ -171,7 +182,6 @@ module Gitlab
         schedule_to_migrate_merge_requests(target)
       end
 
-      # Sync users and groups on rule
       def sync_rule
         unless approvers_exists?
           target.approval_rules.regular.delete_all
@@ -179,9 +189,9 @@ module Gitlab
         end
 
         rule = find_or_create_rule
-
         rule.user_ids = target.approvers.pluck(:user_id)
         rule.group_ids = target.approver_groups.pluck(:group_id)
+        rule
       end
 
       def schedule_to_migrate_merge_requests(project)
@@ -204,7 +214,7 @@ module Gitlab
       end
 
       def find_or_create_rule
-        rule = target.approval_rules.find_or_initialize_by(name: 'Default')
+        rule = target.approval_rules.regular.find_or_initialize_by(name: 'Default')
 
         unless rule.persisted?
           rule.approvals_required = target.approvals_before_merge || 0

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

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Gitlab::BackgroundMigration::MigrateApproverToApprovalRulesInBatch do
+  context 'when there is no more MigrateApproverToApprovalRules jobs' do
+    let(:job) { double(:job) }
+
+    it 'enables feature' do
+      allow(Gitlab::BackgroundMigration::MigrateApproverToApprovalRules).to receive(:new).and_return(job)
+
+      expect(job).to receive(:perform).exactly(3).times
+
+      described_class.new.perform('Foo', [1, 2, 3])
+    end
+  end
+end

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

@@ -83,6 +83,28 @@ describe Gitlab::BackgroundMigration::MigrateApproverToApprovalRules do
 
       it_behaves_like 'sync approval member'
 
+      context 'when project rule is present' do
+        let!(:project_rule) { create(:approval_project_rule, project: target.target_project) }
+
+        it "sets MR rule's source to project rule" do
+          create_member_in(create(:user), :old_schema)
+
+          described_class.new.perform(target_type, target.id)
+
+          expect(target.approval_rules.regular.first.approval_project_rule).to eq(project_rule)
+        end
+      end
+
+      context 'when project rule is absent' do
+        it "has MR rule's source as nil" do
+          create_member_in(create(:user), :old_schema)
+
+          described_class.new.perform(target_type, target.id)
+
+          expect(target.approval_rules.regular.first.approval_project_rule).to eq(nil)
+        end
+      end
+
       context 'when approver is no longer overwritten' do
         before do
           create_member_in(create(:user), :new_schema)