Remove finalize MR approval rule in data migration

Past MR's approval requirement may change if project level setting
ever changed, so finalizing a past MR won't be accurate.

If there is a need to create estimated data,
another optional migration can be implemented.

ee/lib/gitlab/background_migration/migrate_approver_to_approval_rules.rb

@@ -56,13 +56,6 @@ module Gitlab
             scope
           end
         end
-
-        def sync_approvals
-          # Before being merged, approvals are dynamically calculated instead of being persisted in the db.
-          return unless merge_request.merged?
-
-          self.approvals = merge_request.approvals.where(user_id: approvers.map(&:id))
-        end
       end
 
       class ApprovalMergeRequestRuleSource < ApplicationRecord
@@ -105,24 +98,6 @@ module Gitlab
         def sync_code_owners_with_approvers
           ::MergeRequest.find(id).sync_code_owners_with_approvers
         end
-
-        def finalize_approvals
-          return unless merged?
-
-          copy_project_approval_rules unless approval_rules.regular.exists?
-
-          approval_rules.reload.each(&:sync_approvals)
-        end
-
-        private
-
-        def copy_project_approval_rules
-          target_project.approval_rules.each do |project_rule|
-            rule = approval_rules.create!(project_rule.attributes.slice('approvals_required', 'name'))
-            rule.users = project_rule.users
-            rule.groups = project_rule.groups
-          end
-        end
       end
 
       class Project < ActiveRecord::Base
@@ -175,8 +150,6 @@ module Gitlab
           end
 
           target.sync_code_owners_with_approvers
-
-          target.finalize_approvals if target.merged?
         end
       end
 

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

@@ -190,117 +190,4 @@ describe Gitlab::BackgroundMigration::MigrateApproverToApprovalRules do
       end
     end
   end
-
-  # Copied and modified from merge_request_spec.rb
-  describe '#finalize_approvals' do
-    let(:project) { create(:project, :repository) }
-    subject(:merge_request) { create(:merge_request, source_project: project, target_project: project) }
-    let(:target) { merge_request }
-
-    let!(:member1) { create(:user) }
-    let!(:member2) { create(:user) }
-    let!(:member3) { create(:user) }
-    let!(:group1) { create(:group) }
-    let!(:group2) { create(:group) }
-    let!(:group1_member) { create(:user) }
-    let!(:group2_member) { create(:user) }
-    let!(:approval1) { create(:approval, merge_request: subject, user: member1) }
-    let!(:approval2) { create(:approval, merge_request: subject, user: member3) }
-    let!(:approval3) { create(:approval, merge_request: subject, user: group1_member) }
-    let!(:approval4) { create(:approval, merge_request: subject, user: group2_member) }
-
-    before do
-      group1.add_guest(group1_member)
-      group2.add_guest(group2_member)
-
-      rule = create(:approval_project_rule, project: project, name: 'foo', approvals_required: 12)
-
-      rule.users = [member1, member2]
-      rule.groups << group1
-    end
-
-    context 'when without MR rules (project rule not overwritten)' do
-      it 'does nothing if unmerged' do
-        expect do
-          described_class.new.perform(target.class.name, target.id)
-        end.not_to change { ApprovalMergeRequestRule.count }
-
-        expect(approval1.approval_rules).to be_empty
-        expect(approval2.approval_rules).to be_empty
-        expect(approval3.approval_rules).to be_empty
-        expect(approval4.approval_rules).to be_empty
-      end
-
-      context 'when merged' do
-        subject(:merge_request) { create(:merged_merge_request, source_project: project, target_project: project) }
-
-        it 'copies project rules to MR' do
-          expect do
-            described_class.new.perform(target.class.name, target.id)
-          end.to change { ApprovalMergeRequestRule.count }.by(1)
-
-          rule = subject.approval_rules.first
-
-          expect(rule.name).to eq('foo')
-          expect(rule.approvals_required).to eq(12)
-
-          expect(rule.users).to contain_exactly(member1, member2)
-          expect(rule.groups).to contain_exactly(group1)
-
-          rule = subject.approval_rules.first
-
-          expect(approval1.approval_rules).to contain_exactly(rule)
-          expect(approval2.approval_rules).to be_empty
-          expect(approval3.approval_rules).to contain_exactly(rule)
-          expect(approval4.approval_rules).to be_empty
-        end
-      end
-    end
-
-    context 'when with MR approver exists (project rule overwritten)' do
-      before do
-        create_skip_sync(:approver, target: subject, user: member2)
-        create_skip_sync(:approver, target: subject, user: member3)
-        create_skip_sync(:approver_group, target: subject, group: group2)
-
-        merge_request.update(approvals_before_merge: 32)
-      end
-
-      it 'does not call finalize_approvals if unmerged' do
-        expect do
-          described_class.new.perform(target.class.name, target.id)
-        end.to change { ApprovalMergeRequestRule.count }.by(1)
-
-        expect(approval1.approval_rules).to be_empty
-        expect(approval2.approval_rules).to be_empty
-        expect(approval3.approval_rules).to be_empty
-        expect(approval4.approval_rules).to be_empty
-      end
-
-      context 'when merged' do
-        subject(:merge_request) { create(:merged_merge_request, source_project: project, target_project: project) }
-
-        it 'does not copy project rules, and updates approval mapping with MR rules' do
-          expect(subject).not_to receive(:copy_project_approval_rules)
-
-          expect do
-            described_class.new.perform(target.class.name, target.id)
-          end.to change { ApprovalMergeRequestRule.count }.by(1)
-
-          rule = subject.approval_rules.first
-
-          expect(rule.name).to eq('Default')
-          expect(rule.approvals_required).to eq(32)
-
-          expect(rule.users).to contain_exactly(member2, member3)
-          expect(rule.groups).to contain_exactly(group2)
-
-          expect(approval1.approval_rules).to be_empty
-          expect(approval2.approval_rules).to contain_exactly(rule)
-          expect(approval3.approval_rules).to be_empty
-          expect(approval4.approval_rules).to contain_exactly(rule)
-        end
-      end
-    end
-  end
 end