Stop syncing approvals_required once feature enabled

as it is no longer needed.

ee/app/services/ee/merge_requests/update_service.rb

@@ -47,6 +47,7 @@ module EE
 
       # TODO remove after #1979 is closed
       def sync_approval_rules(merge_request)
+        return if ::Feature.enabled?(:approval_rules, merge_request.target_project)
         return if merge_request.merged?
         return unless merge_request.previous_changes.include?(:approvals_before_merge)
 

ee/app/services/ee/projects/update_service.rb

@@ -77,6 +77,7 @@ module EE
 
       # TODO remove after #1979 is closed
       def sync_approval_rules
+        return if ::Feature.enabled?(:approval_rules, project)
         return unless project.previous_changes.include?(:approvals_before_merge)
 
         project.approval_rules.update_all(approvals_required: project.approvals_before_merge)

ee/spec/services/merge_requests/update_service_spec.rb

@@ -60,22 +60,49 @@ describe MergeRequests::UpdateService, :mailer do
     context 'when approvals_before_merge changes' do
       using RSpec::Parameterized::TableSyntax
 
-      where(:project_value, :mr_before_value, :mr_after_value, :result) do
-        3 | 4   | 5   | 5
-        3 | 4   | nil | 3
-        3 | nil | 5   | 5
+      context 'when approval_rules is disabled' do
+        before do
+          stub_feature_flags(approval_rules: false)
+        end
+
+        where(:project_value, :mr_before_value, :mr_after_value, :result) do
+          3 | 4   | 5   | 5
+          3 | 4   | nil | 3
+          3 | nil | 5   | 5
+        end
+
+        with_them do
+          let(:project) { create(:project, :repository, approvals_before_merge: project_value) }
+
+          it "updates approval_rules' approvals_required" do
+            merge_request.update(approvals_before_merge: mr_before_value)
+            rule = create(:approval_merge_request_rule, merge_request: merge_request)
+
+            update_merge_request(approvals_before_merge: mr_after_value)
+
+            expect(rule.reload.approvals_required).to eq(result)
+          end
+        end
       end
 
-      with_them do
-        let(:project) { create(:project, :repository, approvals_before_merge: project_value) }
+      context 'when approval_rules is enabled' do
+        where(:project_value, :mr_before_value, :mr_after_value, :result) do
+          3 | 4   | 5   | 5
+          3 | 4   | nil | 3
+          3 | nil | 5   | 5
+        end
+
+        with_them do
+          let(:project) { create(:project, :repository, approvals_before_merge: project_value) }
 
-        it "updates approval_rules' approvals_required" do
-          merge_request.update(approvals_before_merge: mr_before_value)
-          rule = create(:approval_merge_request_rule, merge_request: merge_request)
+          it "does not update" do
+            merge_request.update(approvals_before_merge: mr_before_value)
+            rule = create(:approval_merge_request_rule, merge_request: merge_request)
 
-          update_merge_request(approvals_before_merge: mr_after_value)
+            update_merge_request(approvals_before_merge: mr_after_value)
 
-          expect(rule.reload.approvals_required).to eq(result)
+            expect(rule.reload.approvals_required).to eq(0)
+          end
         end
       end
     end

ee/spec/services/projects/update_service_spec.rb

@@ -230,14 +230,26 @@ describe Projects::UpdateService, '#execute' do
   end
 
   context 'with approval_rules' do
-    it "updates approval_rules' approvals_required" do
-      stub_feature_flags(approval_rules: false)
+    context 'when approval_rules is disabled' do
+      it "updates approval_rules' approvals_required" do
+        stub_feature_flags(approval_rules: false)
 
-      rule = create(:approval_project_rule, project: project)
+        rule = create(:approval_project_rule, project: project)
 
-      update_project(project, user, approvals_before_merge: 42)
+        update_project(project, user, approvals_before_merge: 42)
 
-      expect(rule.reload.approvals_required).to eq(42)
+        expect(rule.reload.approvals_required).to eq(42)
+      end
+    end
+
+    context 'when approval_rules is enabled' do
+      it 'does not update' do
+        rule = create(:approval_project_rule, project: project)
+
+        update_project(project, user, approvals_before_merge: 42)
+
+        expect(rule.reload.approvals_required).to eq(0)
+      end
     end
   end