Return project approval rules if merge request approval rules is empty

ee/app/models/concerns/approvable.rb

@@ -17,6 +17,7 @@ module Approvable
     committers_can_approve?
     approvers_overwritten?
     total_approvals_count
+    wrapped_approval_rules
   }.freeze
 
   delegate(*FORWARDABLE_METHODS, to: :approval_state)

ee/app/models/ee/merge_request.rb

@@ -275,7 +275,7 @@ module EE
     end
 
     def applicable_approval_rules_for_user(user_id)
-      approval_rules.applicable_to_branch(target_branch).select do |rule|
+      wrapped_approval_rules.select do |rule|
         rule.approvers.pluck(:id).include?(user_id)
       end
     end

ee/spec/serializers/ee/user_serializer_spec.rb

@@ -7,6 +7,10 @@ RSpec.describe UserSerializer do
   let_it_be(:user2) { create(:user) }
   let_it_be(:merge_request) { create(:merge_request) }
   let_it_be(:project) { merge_request.project }
+  let_it_be(:protected_branch) { create(:protected_branch, project: project, name: merge_request.target_branch) }
+  let_it_be(:approval_project_rule) do
+    create(:approval_project_rule, name: 'Project Rule', project: project, users: [user1], protected_branches: [protected_branch])
+  end
 
   let(:serializer) { described_class.new(options) }
 
@@ -33,20 +37,41 @@ RSpec.describe UserSerializer do
     context 'with approval_rules' do
       let(:options) { super().merge(approval_rules: 'true') }
 
-      let!(:approval_merge_request_rule) do
-        create(:approval_merge_request_rule, name: 'Merge Request Rule', merge_request: merge_request, users: [user1])
+      context 'with merge request approval rules' do
+        let!(:approval_merge_request_rule) do
+          create(:approval_merge_request_rule, name: 'Merge Request Rule', merge_request: merge_request, users: [user1])
+        end
+
+        let!(:approval_code_owner_rule) do
+          create(:code_owner_rule, name: 'Code Owner Rule', merge_request: merge_request, users: [user1])
+        end
+
+        it 'returns users with merge request approval rules' do
+          serialized_user1, serialized_user2 = serializer.represent([user1, user2], project: project).as_json
+
+          expect(serialized_user1).to include(
+            'id' => user1.id,
+            'applicable_approval_rules' => [
+              { 'id' => approval_merge_request_rule.id, 'name' => 'Merge Request Rule', 'rule_type' => 'regular' },
+              { 'id' => approval_code_owner_rule.id, 'name' => 'Code Owner Rule', 'rule_type' => 'code_owner' }
+            ]
+          )
+          expect(serialized_user2).to include('id' => user2.id, 'applicable_approval_rules' => [])
+        end
       end
 
-      it 'returns users with applicable_approval_rules' do
-        serialized_user1, serialized_user2 = serializer.represent([user1, user2], project: project).as_json
+      context 'without merge request approval rules' do
+        it 'returns users with project approval rules' do
+          serialized_user1, serialized_user2 = serializer.represent([user1, user2], project: project).as_json
 
-        expect(serialized_user1).to include(
-          'id' => user1.id,
-          'applicable_approval_rules' => [
-            { 'id' => approval_merge_request_rule.id, 'name' => 'Merge Request Rule', 'rule_type' => 'regular' }
-          ]
-        )
-        expect(serialized_user2).to include('id' => user2.id, 'applicable_approval_rules' => [])
+          expect(serialized_user1).to include(
+            'id' => user1.id,
+            'applicable_approval_rules' => [
+              { 'id' => approval_project_rule.id, 'name' => 'Project Rule', 'rule_type' => 'regular' }
+            ]
+          )
+          expect(serialized_user2).to include('id' => user2.id, 'applicable_approval_rules' => [])
+        end
       end
     end
   end
@@ -61,11 +86,6 @@ RSpec.describe UserSerializer do
     context 'with approval_rules' do
       let(:options) { super().merge(approval_rules: 'true') }
 
-      let!(:protected_branch) { create(:protected_branch, project: project, name: 'my_branch') }
-      let!(:approval_project_rule) do
-        create(:approval_project_rule, name: 'Project Rule', project: project, users: [user1], protected_branches: [protected_branch])
-      end
-
       it 'returns users with applicable_approval_rules' do
         serialized_user1, serialized_user2 = serializer.represent([user1, user2], project: project).as_json
 
@@ -79,7 +99,7 @@ RSpec.describe UserSerializer do
       end
 
       context 'with target_branch' do
-        let(:options) { super().merge(target_branch: 'my_branch') }
+        let(:options) { super().merge(target_branch: protected_branch.name) }
 
         it 'returns users with applicable_approval_rules' do
           serialized_user1, serialized_user2 = serializer.represent([user1, user2], project: project).as_json